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Lecture 2 Fundamental Concepts 31014 921 AM Fundamental Concepts Key concepts 0 Different time scales of response o Regulation o Homeostasis How fast things can change in an organism Biochemical buffering and gene expression can change within minutes Physiological flexibility can change within days or months Behavioral responses can change from days to years Genetic drift selection happens in months to decades Evolution occurs over decades to millennia Ecological interactions can take from minutes to decades In this class we are looking at responses such as genetic drift behavior physiological flexibility gene expression and biochemical buffering More complex animals require more and more time to evolve Physiological response on different time scales Different time scales o Short term acute scaring someone getting burnt o Acclimatization getting used to a condition in hours days o Acclimation o Developmental temperature dependent sex determination TSD o Genotypic change true adaptation local adaptation Short term acute responses o Physiological biochemical or anatomical changes within an animal during its lifetime o Results from an ACUTE exposure in the natural environment to new naturally occurring conditions 0 Generally reversible o EX Humans at high altitude decreased oxygen content with altitude at less oxygen contents people experience many forms of impairment People can expose themselves to these harsh conditions and make themselves more fit to be at high altitudes Acclimatization 0 Physiological biochemical or anatomical change within an individual animal during its life 0 Results from CHRONIC exposure in the natural environment to new naturally occurring conditions 0 Generally reversible o Organisms have to be able to adjust themselves rapidly to survive o EX Blue crabs estuaries and salinity Live in oceans and fresh water have to be able to adapt to high salt content Photosynthesis algae salt wind differ as well in the two mini habitats Gradient of salinity in estuaries These crabs can tolerate high salinities in the water Acclimation 0 Physiological biochemical or anatomical change within an individual in its lifetime 0 Experimentally induced by an investigator 0 Generally reversible o EX African jewelfish is an invasive species in coastal estuaries Scientists have studied that these fish can tolerate high levels of salinity 0 ANALYSIS make a conservative recommendation as a result of this experiment on the jewelfish Will warming or cooling of regions of the estuary influence the invasion proceeds Group Justine 805 674 1707 Mike 559 936 7303 Chris 805 350 3303 Deirdre 858 603 9549 Physiological Regulation Strategies for coping with changing conditions Conformers o Allow internal conditions to change when faced with variations in external conditions 0 Internal environment adjusts to reflect external conditions Regulators o Maintain relatively constant internal conditions regardless of the conditions in the external environment 0 Keep internal environment within narrow limits Homeostasis Maintenance of internal conditions in the face of environmental perturbations Controlled by feedback loops or reflex control pathways 0 Negative feedback loops 0 Positive feedback loops Unifying themes in physiology Physiological processes obey physical and chemical laws Physiological processes are usually regulated Physiological phenotype is a product of the genotype and the environment Genotype is a product of evolution Lecture 2 Intro to Marine Systems Modern Day Oceans Two large basins pacific and Atlantic Largely stable Smaller enclosed arctic ocean and smaller seas like the Red sea lots of evaporation and the Mediterranean Each has its own critical hot spots of biodiversity determined in part by the oceanography Sea Water Chemistry Maintained by geochemical cycles in the ocean Dominated by Na 30 and Cl 55 ions 0 Calcium highly significant for biogenic calcification Water Salinity Fresh water gt5 Brackish water 5 30 Saline 3050 Brine gt 50 Most marine invertebrates are osmoregulators Stresses for marine life 0 Open ocean fairly stable chemically some temp variation specific to latitude o Other marine ecosystems quite challenging Consume seawater Have water loss through skin Concentrated salty urine Mg SO2 Active ion transport through gills Pass of ions in and out of their body Na K Cl Organisms have to keep their body at a different level than the ocean which requires all of these different physiological mechanisms World ocean thermohaline circulation Hot and cold currents within the ocean Open oceans are very low in primary productivity cholorphyll Diel Vertical Migration Organisms move in the water column Depending upon what time of day it is organisms change their location During the day the organisms go deeper At night they migrate to the surface At night visually acclimated predators cant predate on them so organisms go to the top to feed What were going to look at Ice filled environments 0 Threatens organisms with freezing o Organisms have developed proteins that allow them to not have their insides freeze absence of ice crystals 0 Arctic has a phytoplankton boom Intertidal Zone 0 Extreme environment in which organisms experience extreme temperature changes changing tides desiccation Estuaries 0 Mix of ocean and fresh water Dead zones All of the oxygen is taken out of the water hypoxia Organisms die because of this Occurs in days or weeks at time Happens because of agricultural runoff into oceans Its like over respiration of the water because there39s too many constituents Major processes 0 Process Example Ionic and osmotic physiology Osmoregulation and a fish gill and adaptations Temperature Variable thermotolerance in intertidal benthic invertebrates Respiratory Vertical migrating species Reproduction Different larval forms with different feeding and developmental strategies Locomotion Swimming burrowing in sediment Sensory and signaling Vision bioluminescence in the deep sea Feeding Filter feeding Lecture 4 Temperature and Marine Systems 31014 921 AM Temperature has profound effects on biological systems Rates processes are influenced o Mitosis reproduction ect Can influence energy balance 0 Alter how organisms use their energy Lethal limits CT max critical temperature max highest temperature they can operate before the organism starts to fail Structure communities and influence species range limits 0 Where they live where they39re able to reproduce 0 Trend seen when climate starts to warm migration organisms try to find their optimal climate after their own climate has changed Temperature amp Marine Life Reversible acclimation of one species how plastic are they in response to environmental temperature change Prentice paper on crab acclimation Developmental acclimation in guppies Evolutionary local adaptation to temperature Sanford paper Diel Scale vertical migration short term response through varying temperatures and physiological costs Reversible acclimation First discovered in 1824 in a study on birds summer birds did better in confined air than winter air Winter birds have higher metabolic rates seasonal acclimation Winter birds died faster than summer birds in oxygen poor environments 0 Winter birds need more oxygen Discoveries in the lab acclimation responses to metabolic rate As temperature drops there are 5 distinct responses observed by organisms o 1 Overcompensation organism overshoots the metabolic rate that it hard before 0 2 Perfect compensation comes back to same level 0 3 partial compensation almost comes back 0 4 No compensation organism doesn39t compensate at all o 5 Reverse compensation looks almost like hibernation dormancy cold cue winter go into really low metabolic state to save energy during a cold period EX Mytilus edulis mussel Perfect example of perfect compensation Really good at maintaining their metabolic rate in varying climates live in a very diverse climate It only takes them 14 days to return to their perfect level Change in metabolic rate of crabs cancer magister Acclimated crabs to 2 temperatures 75 and 175 Researchers thought that the low temps should have the highest metabolic rate but they had the lowest think that maybe it was starting dormancy Van T Hoff equation for Q10 value for comparing organisms responses to temperatures 0 Q10 how much temperature influences rate process per 10 degrees Developmental Acclimation Developing organisms may have their physiologies forever altered Can have huge impacts on the next generation of species Especially in ectothermic animals such as fish increased temperatures causes resting metabolic rate RMR to increase Good or bad 0 Can be beneficial because helps organisms developed quicker 0 But come at a cost changes what the organism has to do with its energy budget 0 Organism always has an allotted amount of energy with which to do its processes Maintenance renew proteins build new muscle maintain body keep body going 2 When metabolic rate goes up more energy needs to be applied to body maintenance and that means there is less energy available for the other processes Reproduction Growth Reversible acclimation in tropical guppies Raised guppies at various temperatures for 70 days 23 25 28 30 0 2328 normal 0 2830 pretty warm found that there is a reduced body size at higher temperatures 0 usually females were larger than males 0 both fish saw a reduction in body size but the reduction was greater for females 0 this decrease can be attributed to the fact that increased RBR caused a decrease in energy to be supplied to growth how can that additional cost to energy expenditure be explained o Guppies reared at 30 degrees had significantly higher metabolic rates than the others 0 Really big cost to those individuals being at a higher temperature why they have such a smaller size Metabolism as a measure of performance and response to environment Metabolism use of energy by organism Creates heat thermogenesis and energy Heat can be measured directly or indirectly 0 Direct calorimeter o Indirect oxygen consumption way to measure basal metabolic rate BMR post digestion laying down completely at rest RMR for aquatic animals resting metabolic rate energy expended at rest while it just sits there and doesn39t swim Lecture 4 Temperature Part II 31014 921 AM Historical observation 1920s waves of studies on tolerances and distributions 19505 a function meets biogeography perspective emerges 19705 species tolerances a physiological perspective 1980s biochemical adaptations 19905 evolutionary physiology 20005 post genomic era Example then and now Then the effect of temperature in limiting the geographical range of invertebrates in the woods Now could you identify physiological traits across latitudes in organisms Abundant center hypothesis Says that if we look at a gradient of stress across which an organism might live there39s a place in the middle of the range where everything is optimal food desiccation temperature and as a result of this more organisms reside in the center of their range than the edges 0 At the edges we should be able to observe a scarcity of resources or some limiting factor that creates a smaller population Experiment channeled dogwhelk nucella canaliculata 0 Found that in the center there actually are many more organisms 0 Also found more stress proteins at the edges of distribution 0 Thermotolerance of dogwhelks How does this pattern of Thermotolerance evolve Life history traits embryo to adult influences evolutionary capacities Nucella moms create tiny egg capsules for their babies so they39re protected in the intertidal zone 0 The babies then crawl away from their parents but they really don39t get very far 0 Babies don39t disperse very far o Called oca adaptation the fine tuning of physiological responses of an organism to its environment genetic response LT50 experiment ofjuvenile snails Results were unexpected but then they found that in CA and OR there are discrepancies in the temperatures of the intertidal zone 0 Low tide exposure in the north results in hot temperatures in the summer Diel pattern of migration DVM Perhaps largest migration on Earth biomass wise These organisms migrate to the surface at night and fall back into the depth during the day Compared to their body size these organisms travel enormous distances 100s of meters Now scientists can use echosonder to see the abundance of certain organisms at different depths 0 Why do this Millimeter length organisms move 300 meters in a day What is the strategy that makes these organisms expend so much energy Costs consequences and adaptive value 0 Huge costs in energy swimming 0 Maybe there39s a metabolic advantage from going to the surface 0 When its cold they have a lower metabolic rate 0 There39s also less foodslower growth at the bottom Two categories of hypotheses 0 Vertical migration provides a metabolic advantage Views and results 2 Variable temperature does not seem to provide a clear advantage notably warmer T in surface waters does not seem to increase feeding rate enough 0 Avoiding surface waters during the day reduces predation risk by visual light dependent predators Views and results 2 Good evidence for this although there are several different patterns in several taxa 2 Percentage of larvae with and without predators 0 Without higher heights With lower heights Better hungry than dead 2 Energetic saves metabolic advantage theory vs predator avoidance this one seems to win 2 Adaptive behavioral response to predation 2 Evolved more than once in divergent taxa 2 Reverse DVM have been observed WRITING ASSIGNMENT 1 Photoessay 1 due Wednesday 22 January by 5pm 0 Please capture an image fro the local intertidal sites 0 Write a caption for your image that describes the organism environment interactions that your image captures Lecture 5 Temperature and the Intertidal 31014 921 AM Emerging new physiological challenge from the environment Environmental gradients can be steep Salinity variation Aerial exposure exposure to air during a low tide Desiccation stresses Exposure to predators Organismal responses Varying tolerances Adaptations New behavioral responses Avoidance as a strategy Timing The Rocky Intertidal zone steep environmental gradients Thermal stress in rocky intertidal What sets patterns of distribution in nature Is it physical abiotic factors of species interactions biotic Two examples 0 Mussels o Porcelain crabs Porcelain crabs High intertidal rocky more sun less water more air Middle intermediate more movement of water rapidly changes Low mostly water less air cooler movement Petrolithes cinctipes high intertidal zone 0 Lighter in color 0 Experience much higher temperatures more temperature stress possible adaptations 0 Upon measuring heart rate ABT it was determined it occurred at 315 Tolerates a much higher temperature range as demonstrated by its fine tuning of heart function Petrolithes eriomerus low intertidal zone 0 Darker in color 0 Experience lower temperatures 0 ABT 266 much lower because it lives at lower temperatures Mussels Form vast beds that are habitats for other organisms Beds have distinct boundaries 0 Spend a lot of time and effort trying to stay in this bed 0 Have adductor muscles bysall threads to keep them in place Biological filters Keystone effects on coastal phytoplankton because they filter so much water Important link in the food web in coastal areas Mussels drastically change their body temperatures throughout the day Mussels are bigger in the low intertidal more feeding more water filtering through What are the physiological challenges and what are the costs 0 Protein denaturation o Apoptosis o Ubiquitin proteasome system Protein homeostasis 0 Maintain the amount of functional protein in an organism 0 Prevention of aberrant protein behavior quality control multiple processes 0 generally speaking stabilize protein conformations refold misfolded proteins degrade proteins that are detrimental to cell 0 how to fix sticky proteins eukaryotic chaperone proteins 2 many other proteins running around that prevent sticky proteins from aggregating and also have surfaces that allow sticky proteins to unclump ubiquitination system 2 large structure called proteasome used when protein cannot be refolded 2 ubiquitin molecules are placed on denatured proteins that signal proteasomes to destroy the faulty protein then the amino acids can be used to make new proteins 2 if many proteins have to go through this pathway it is an energetic loss to the organism 0 thermal stress sets the upper limits of their habitats Species interactions Predator prey pair mytilus and pisaster 0 Different response to abiotic environment 0 Predation sets the lower limit of the mussels Experiment where predators were removed from the mussels environment to see if their lower limit would expand and it did Lecture 5 Hydrothermal Vents 31014 921 AM Ecophysiology of the Hydrothermal Vents Two case studies Until 1977 we thought that photosynthesis was the energetic basis for all food webs Forms the basis of all terrestrial food webs Photonic energy captured in chloroplasts Microscopic algae are the primary marine source of most marine animals Used to fix carbon dioxide Even responsible for deep sea life Detritus bacteria and fecal matter rain down to the sea floor known as marine snow 0 Very slow input 0 Most of the deep sea doesn39t have very much biomass due to this slow movement Hydrothermal vents discovery Used DSV ALVIN submarine could go down 4000m deep o Had good thrusters to move agilely In the 1970s continental drift wasn39t a widely accepted theory 0 So scientists were looking down in the bottom of the ocean for evidence volcanoes earthquake faults mountains hot sp ngs o While diving they found the Galapagos Rift 1977 Nobody knew what it was Started this geological survey of geological vents Found that these types of ridges exist all along edges of tectonic plates Located where the youngest hottest rocks on our planet are formed Chemistry of Vents Red Ox chemistry drives life at vents Reduced chemicals in hot vent water Oxygenated seawater Created opportunities for biological growth Superheating water and comes shooting out of the vent o This reduces many different chemicals as they rise towards the surface 0 Can also oxygenate water Environmental Conditions Temperature 0 Ambient deep sea temperature 20 C o Vent water up to 450 C 0 Also creates water around 20 C around it which is perfect temp for life Oxygen 0 Ambient 110 pM o Vent water anoxic due to chemical consumption Metals and dissolved gasses Pressure pH How do these organisms survive in such difficult conditions Chemoautotrophic bacteria Never had thought it would be the basis of an entire ecosystem but it is Fix sulfur instead of carbon in a similar way to photosynthesis still forms sugar Animals take advantage of these bacteria by forming symbiotic relationships with the bacteria Riftia Pachyptila case study 1 Really tall up to 6 feet tall Has no way to actually feed for itself not gut mouth or anus Instead has lots and lots of bacteria to feed it o All of the bacteria symbionts requirements such as CO2 H2S O2 and N03 are provided by the worm Everything that the symbiont and worm exchange are diffused through the plume 0 Starts with the transport of CO2 most animals have it as a waste product but the tube worm actually takes it in abundance so that the symbiont can fix it into food 0 CO2 diffuses naturally because it is uncharged Use carbonic anhydrase to convert CO2 to HCO3 so that it can travel further into the animal and be stored in the trophosome and allow even more CO2 to be taken up by the worm BUT the symbiont needs CO2 so there is a second enzyme that converts the HCO3 in the trophosome back into C02 0 The worm also has to be able to take up H2S but it is toxic So how do they transfer large amounts of sulfide if its toxic They use hemoglobin Sulfur scavenges hemoglobin more easily than oxygen which is why it is toxic to humans outcompetes and never unbinds These worms have a separate receiver for hemoglobin cysteine group which allows the hemoglobin to actually transport sulfide and oxygen at the same time Allows them to bring in sulfide without damaging themselves 0 ALSO needs nitrate Convert nitrates into ammonia to transport them to their symbionts How was this data collected Live experiments onboard the ship 0 High pressure respirometry system 0 System required high pressure pumps dissolved nutrient injection pumps dissolved gas mixture high pressure aquaria in temp controlled water bath analytical equipment Calyptogena Clam Also can take up sulfur 0 Use their feet Methane Cold seeps Similar to hot vents Have found some organisms that can live for 300 years because of how slow the methane is released Shallow mudflats Lots of sulfur Have bacteria that fix sulfur Thermal tolerance to Alvinellids Animal thermal tolerance very different than microbes o Microbes can survive huge amounts of heat Animal thermal tolerance is much lower proteins start to break down damage to nervous systems and membranes 0 Most max out around 50 C Alvinellids have been observed in sitiu at 60 C 0 That means their proteins have to be able to work at really high temps This worm is found along rises really close to the heat underwater They live in little tubes right next to the vents 0 But not at 400 C could only be about 100 C 0 Inside the tube always measured at 60 C which is incredible Animals were brought back for testing to the ship to see how high their proteins could stand but proteins only survived up to 55 C o This doesn39t make sense if the animals can live at over 60 C BUT cannot bring these animals back up to surface to study this effect BUT there is another animal in this worms family that can be brought up to the surface 0 Don39t live in quite as hot as temperatures but still hot 50s C 0 Lives in vents at 2200m deep 100300 C 0 Wanted to see how hot this animal could stand and what temp it prefers Put worm in chamber with different temps and found that they preferred water above 40 C 2 Why We don39t really know yet 2 Possibly a competition issue can survive temps other organisms cant so it has more room to live and feed 2 Doesn39t have symbionts so actually has to feed on bacteria 2 Has an entire environment to feed without competition Acute and Chronic Temperature UILT upper limit of animals thermotolerance where it cant survive for much longer Sulfincola has the highest UILT found in all animals 53 C o Sulfincola actually dies also if you go below 10 C even though the rest of the ocean is about 2 C 0 However palmiformis can live up to 37 C but can survive down to 0 C o Organisms have to find their own separate niches in order to survive and reproduce Bacteria Some bacteria can survive at really really hot temperatures Some actually reproduce faster at really high temps Only reason you can survive over 100 C is when there is enough pressure to resist boiling Origin of life All of this leads to the origins or life Number one suspect is at the hydrothermal vents 0 Has reductive chemicals spontaneous generation of amino acids 0 This means you could actually create life from non life here if given millions of years 0 Some of the oldest archaea are still found in hydrothermal vents o On land we didn39t even have the opportunity to create energy through photosynthesis so chemical energy could have been made but only at these hydrothermal vents Summary of Week 1 Readings 31014 921 AM Harley 2011 Science Pisater and Climate Change Warming substantially reduces predator free space on rocky shores Vertical extent of mussel beds decreased 51 in 52 years Mussels will extend their lower limit significantly if predation threats disappear Upper limits of mussel beds are set by temperaturelower by predation Understanding how biotic and abiotic factors work together especially with regards to climate change Crab Respiration Prentice 1979 Crab cancer magister Want to find out if 1 the crabs metabolism would adjust in an adaptive manner when faced with elevated temperatures and 2 if the upper lethal temperature limit would be altered with a change in acclimation temperature Found that crabs more acclimated to cold water had higher rates of oxygen respiration at higher temperatures than crabs acclimated to warm water Cold acclimated crabs had a lower lethal temperature than warm acclimated crabs Kuo and Sanford 2009 Wanted to test if organisms had been genetically altered to their environment Tested nucella snails from central CA northern CA and OR to find out their lethal limits of temperature Central CA snails were less heat tolerant than snails from OR potentially because snails in OR experience more daily stress than those in CA Intertidal zone reading Marine Biology 216233 Explains parts of the rocky intertidal zone and its characteristics including the animals that inhabit it Metaxas Larval Migration Paper Studied larval response to predators by measuring how high and low they travel during the day When predators were present in the cage the larvae returned to a lower position in the experimental columns as compared to when there were no predators This behavior suggests that the huge migration the larvae undertake is mostly to avoid being eaten by predators Munoz 2012 Developmental Acclimation Wanted to test how temperature affected body size in guppies Found that fish who had to live at higher temperatures had significantly reduced body size This is because the organism has to allocate more resources to maintaining its temperature and not as many to growth Sheridan and Bickford 2011 Examines a lot of cases where organisms shrink due to changing climates Concludes that organisms will shrink but this shrinkage will differ among taxa and we don39t know how this will affect organism interactions Sorte and Hoffman 2004 Abundant center hypothesis with nucella mussels Concluded that mussels prefer to be at the center of their range and that abundance shrinks at the edge of their range Also found stress levels to be higher at the edge of their range and lower in the middle Summary of Week 2 Readings 31014 921 AM Van Dover Lutz 2004 Examines deep sea hydrothermal vents Sulfur uptake system in Riftia worm special hemoglobin Symbiotic relationships between bacteria and other organisms for energy using chemoautotrophic mechanisms Some of the hottest places documented where organisms can live Baker Nature Corals have been found to respond to warming with adapting a more heat tolerant symbiont after recovery from bleaching Maybe corals with these special thermal symbionts will be able to withstand global warming better Rowan Nature Examined symbiont C and D and found that D is much more heat tolerant Also found that corals located in warmer climates are more likely to have symbiont D as their symbiont Berkelmans 2006 Corals and Transplant Experiment Found that corals could somewhat acclimate to warmer temperatures by switching to symbiont D instead of C Oliver and Palumbis 2009 Symbiont Diverstiy Found that clade D is present in acclimation to warmer temperaures only at a local not regional scale Lecture 7 Coral Reefs and Temperature 31014 921 AM Exam Cover lecture 1 through next Monday Thermal Biology of Corals What are corals 0 We think of them as a holobiont 0 Made up of many polyps in colonies colonial organisms 0 Each polyp has a stomach that opens at only one end with an opening surrounded by tentacles 0 Some corals can be huge have variable morphologies 0 Dominant in their environment Symbiosis 0 Most reef building corals contain photosynthetic algae called zooxanthellae They are a group of single celled algae that live in and around the tissues of coral 0 Have a mutualistic relationship algae get protection and give coral food Algae supply the coral with glucose glycerol and amino acids Coral uses these products to make proteins fats and carbohydrates and produce their calcium carbonate skeletons As much as 90 of the organic material photosynthetically produced by the algae is transferred to the host coral tissue Coral adaptively polytrophic 2 This allows coral reefs to grow quickly Symbionts in return receive inorganic nutrients from the hosts waste 0 Have a huge number of algae per coral sometimes called a keystone species because they have a small biomass in relationship to their ecological effect Reef building by corals Reefs form when polyps secrete skeletons of calcium carbonate The skeletons of stony corals are secreted by their lower portion of the polyp Coral reefs have huge ecosystem services Coral reefs are vulnerable to disturbances Storms PoHuHon Excessive UV radiation Changes in salinity Changes in sea level Physical destruction by humans Over fishing Heat stress Coral bleaching A stress from a warming ocean Coral algae symbiosis is delicate and collapses in response to adverse environmental conditions most notably elevated temperature The loss of symbionts residing in corals coral bleaching It is the symbionts that give the corals their color without the they are white Many corals are already living near their upper critical limits for temperature 0 Even small temperature changes could trigger bleaching How do we assess the likelihood of bleaching 0 Degree heating weeks DHWs Monitor when sea surface temperatures exceed 1C about the maximum summertime mean DHW shows how much heat stress has accumulated in an area over time When algae are exposed to too much stress they start to secrete toxic radical oxygen 0 That makes the coral expel them because they39re toxic o This loss of symbiont coral bleaching o Bleached corals are not dead but if they don39t recover their symbionts they could die 0 They can recover their symbionts if the exposure to high temperatures is brief but even recovered corals show some damage o Mechanism of bleaching On the onset of thermal stress there is a reduction in the activity of photosystem II in the symbiont chloroplasts Due to direct damage of PSII photosynthesis is also damaged The break in photosynthesis causes oxygen free radicals to accumulate and this is toxic to the coral 9 symbiosis break down Debate Coral Bleaching Stress response as outlined above Adaptive bleaching hypothesis ABH o Premise bleaching is a regulated mechanism that corals use to switch out symbionts in response to variable environmental conditions 0 Could facilitate and promote adaptive changes in coral symbiont associations Exam 1 Study Guide 31014 921 AM Topic Introduction of Principles in Ecological Physiology What are the four core principals of ecological physiology 0 Physiological processes obey physical and chemical laws Physiological processes are usually regulated Physiological phenotype is a product of the genotype and the environment Genotype is a product of evolution is acclimation different from acclimatization Acclimation is a physiological biochemical or anatomical chance that takes place within an organism that is experimentally induced by an investigator or in a lab while acclimatization results from chronic exposure in an environment with new naturally occurring conditions Compare and contrast a regulator and a conformer O VVhat And conformer is an organism that adapts to a changing environment by allowing their internal conditions to change as well while a regulator seeks to maintain a constant internal environment even while the external environment is changing is homeostasis Give a specific example Homeostasis is when an organism maintains its internal environment despite environmental perturbations it is usually controlled by feedback loops or reflex control pathways An example of this is the interaction between insulin and blood glucose levels When blood glucose levels get too high insulin is released in order to absorb glucose and convert it to glycogen lowering blood glucose levels How does temperature affect physiological rate processes 0 It increases the rate at which these processes occur Topic The Open Ocean Marine Environment What are some features of the open ocean that define how animals have evolved in this environment think response to temperature salinity wave forces upwelling O Seawater chemistry is maintained by geochemical cycles in the ocean contains different chemicals normal seawater is around 3235 ppt the open ocean is fairly stable chemically salinity varies due to ocean currents depth and temperature thermohaline circulation What are dominant ions What is biogenic calcification o The dominant ions in the ocean are Cl Na sulfate calcium potassium and magnesium Biogenic calcification is when organisms in the ocean create calcium carbonate shells This process not only helps the animals physiologically but also plays a key role in biogeochemical cycling as ballast for sinking particulate matter and by transporting carbon and alkalinity to depth via the biological pump Discuss how the salinity of saline open ocean seawater differs from freshwater o Freshwater has a salinity level of lt05 while seawater has a level of 3050 Does the average sea surface salinity of the worlds ocean vary If so how 0 Yes it varies from 3130 PSU The reason for this is because of the world ocean thermohaline circulation Discuss a marine ecosystem that has high biodiversity o Intertidal zones have high biodiversity because of the different climates sectioned in such a small area Topic Temperature Relationships in Marine Animals Understand and explain the Q10 concept 0 The Q10 coefficient is a measure of the rate of change of a biological or chemical system as a consequence of increasing the temperature by 10 C a Q2 means it doubled How did oxygen consumption change in the crab acclimation study 0 They found that crabs acclimated to warmer temperatures consistently had higher rates of oxygen respiration but the crabs acclimated to lower temperatures showed a greater increase in rates from low to high temperatures inverse acclimation What is diel vertical migration DVM 0 When organisms migrate from the depth to the surface at night and back again during the day short term response What is meant by the term LT50 How is it calculated o LT50 is a measure that studies how much of an effect temperatures have on an organism The LT50 value is the value where half of the organisms exposed to a certain temperature die It is calculated experimentally Topic Coral Reef Lecture and Coral Bleaching What is bleaching How does it occur What are the mechanisms and hypotheses regarding this phenomenon o Coral bleaching occurs and leaves a coral looking white This white color is the result of a coral losing its symbiont usually a phototrophic algae with which coral forms a symbiotic relationship The algae provides the host with nutrients such as organic carbon and sugars that it creates from the host39s waste products and the host provides the algae with shelter When the conditions turn unfavorable for the symbiont or the coral coral bleaching occurs because all of the symbiont is lost What are Symbiodinium 0 These are the symbiont algae that live alongside coral in a symbiotic relationship They are photosynthetic Describe the nutritional physiology of the coral holobiont o The Symbiodinium are photoautotrophs meaning that they can create their own food from inorganic chemicals and sunhght Are corals living at the edge of their thermal tolerance o It is suggested that yes they are Are there high temperature specialists in the Symbiodinium clades What is the evidence o Yes There have been studies done that show that after being exposed to high temperatures after a coral bleaching coral will pick up Symbiodinium that are more heat tolerant as a way to adapt to their new warmer climate clade D Topic Temperature and the Rocky Intertidal What are physiological challenges faced by intertidal marine invertebrates 0 These organisms face new stresses including steep environmental gradients salinity variation aerial exposure desiccation stress and exposure to predators Discuss the gradients of environmental stress that are found in the rocky intertidal o Organisms that can live in and out of the water experience temperature gradients desiccation gradients and salinity gradients The seawater often has very different levels of theses factors than does the dry air What are the divisions in the intertidal How do abiotic factors vary across the intertidal and what are the physical stresses faced by organisms o The low intertidal is completely submerged and faces the stresses of salinity and also of dealing with the physical stress of the powerful waves and currents The mid zone is the most stressful because organisms are forced in and out of the water daily as a result of changing tides This leads them to experience vast differences in the conditions listed above The upper intertidal zone is the most subject to desiccation because they are in the sun more than the water Temperature is also a large factor in this zone How do organisms differ as a function of their thermotolerance as a function of their distribution in the intertidal eg the porcelain crab example 0 In the experiment with the crabs it was found that crabs located at lower zones had a lower tolerance of heat They were also darker in color which suggests they are not subject to much heat The crabs from the upper intertidal were much more tolerant of heat stress They were lighter in color which suggests they are in heat more How do abiotic conditions vary as a function of tidal height 0 In higher areas organisms are emersed from the water longer than those located at lower tide heights These organisms are more adapted to emersion stresses than those at lower levels What sets the lower limit of the mussel bed The upper limit Describe the experimental evidence 0 The upper limit is set by thermal stress because mussels cannot live above a certain temperature without protein degradation The bottom limit is set by predation by sea stars This was determined because when sea stars were removed from the mussels environment they had a larger distribution What are heat shock proteins Hsp What is protein homeostasis 0 Heat shock proteins are a group of proteins induced by heat shock They stabilize proteins and are involved in the folding of denatured proteins Protein homeostasis is the prevention of aberrant protein behavior It is the process of stabilizing protein conformations refolding misfolded proteins and degrading proteins that detrimental to a cell after the proteins have been subjected to some stress How is protein homeostasis maintained in cells 0 There are two mechanisms chaperone proteins and the ubiquitin pathway The chaperone proteins prevent sticky proteins unfolded proteins from aggregating They also provide a surface on which these sticky proteins can unclump and refold The ubiquitin pathway contains a large structure called a proteasome and are used only when a protein cannot be refolded Ubiquitin molecules are placed on denatured proteins that signal proteasomes to destroy the targeted protein The amino acids can then be used to make new proteins this is an energetically unfavorable pathway Describe the changes in Hsp levels that occur in organisms in response to thermal stress in their environment on the short term acute stress vs over a longer period of time eg a series of low tides o In both cases there is an up regulation of HSP proteins Topic Polar Seas Freezing Avoidance What are the unique environmental challenges that are faced by Antarctic marine organisms 0 These organisms have to deal with extremely cold temperatures which puts them at risk for being frozen large amounts of ice Extracellular ice formation can result in physical damage to the organisms cells dehydration and also an unfavorable build up of solutes inside or outside the cell What is the role of antifreeze glycoproteins AFGP in Antarctic notothenoid fish 0 AFGP proteins exist to help fish avoid their cells being lysed by large chunks of frozen ice that occur inside their cells How did AFGP evolve o It is thought that these proteins evolved by means of evolutionary convergence There were different species of fish that independently evolved the invention of the same glycoprotein as needed by their environment There are different genes responsible for the AFGP origin in different species of fish which leads to the convergent evolution hypothesis How do they work to inhibit ice crystal formation 0 AFGPs work by inhibiting ice propagation across membranes inhibit recrystallization of small ice crystals and displace the freezing point of the ice to a lower temperature This AFP induced separation of the melting and freezing temperatures is called thermal hysteresis Topic Deep Sea Vent Environments What are the abiotic stresses at deep sea vents 0 At deep sea vents the temperatures can reach up to 400 C which promotes areas around it to also be at temperatures higher than usual for life Also the water in the vents is anoxic due to chemical consumption There are redox reactions that take place with the chemicals around the vent there are many dissolved metals and gasses Also the pH differs there from that of the open ocean from 6 to 2 and the pressure is much greater How are vent sites studied How were they discovered o The vents were discovered in the 70s when scientists were on the DSV Alvin submarine looking for evidence of plate tectonics when they discovered the Galapagos Rift Today they are still studied using submarines and scientists can bring organisms to the surface to conduct tests on them What are the adaptations that occur in deep sea vertebrates 0 First of all there are chemoautotrophic bacteria that provide energy for these deep sea animals They convert inorganic carbon into organic carbon using chemical energy Some animals such as the Riftia Pachyptila use these bacteria as symbionts to feed meaning they get their energy purely from the chemical processes of bacteria They have specialized hemoglobin to transport sulfur around their body to the bacteria Other organisms are also extremely well adapted to high heat through mechanisms still unknow Lecture 8 Freezing and Polar Seas 31014 921 AM Polar Regions 70 of the earths surface is ocean but most of that ocean is 4C or less 0 but most of what we study is 10C physical properties of polar waters 0 temperature is very very low o has stable salinity o ice is the biggest problem 9 huge amounts of ice cryosphere 3D structure Fish famous for freeze resistance Notothenioids endemic Antarctic marine fish Sub Antarctic island 3050 endemic Continental 76 general are endemic 88 of the species are endemic The dominant family can make up 99 of the fish biomass in a given sampling area Most diverse in body form sizes habitat and distribution There are few species with many forms Adaptations o Internal ice nucleation Controlled ice formation Convergent evolution of antifreeze proteins o Freeze avoidance Why is water staying liquid so critical 2 Because when ice forms you get sharp jagged edges that can break cells How is freeze avoidance accomplished 2 Colligative mechanisms freezing point depression Polyhydric alcohols commonly used glycerol trehalose and sorbitol Disadvantages expensive have to use a lot of substrate and ATP to keep making solutes 2 Macromolecular antifreezes Have a thermal hysteresis doesn39t stop freezing but changes the temperature at which it happens Found it had to be a really big molecule to act as antifreeze All have diverse structures but a common mechanism of action Evolutionary convergence in antifreeze glycoprotein structure 0 Independent evolutionary invention of same glycoprotein 0 Sizes very 337000 2600 0 Different genes responsible fro AFGP origin in cod and notothenioids o Trypsinogen gene was ancestral AFGP gene o It inhibits ice propagation across membranes stops uncontrolled growth of small ice crystals to damaging sizes Damage from extracellular ice formation El Intercellular water freezes inside the cell and ruptures parts of the cell membranes Concentration of solutes in the extracellular space May lead to inhibition of metabolism ect Lecture 9 Ecophys of Marine Vertebrates 31014 921 AM Marine Vertebrates Ectotherms bony fishes frogs sea turtles Endotherms marine mammals Environmental Stresses for Marine Mammals Osmotic and ionic challenges 0 Swimming around in sea water o Drinking and consuming the sea water Temperature regulation 0 Some live in almost freezing water 0 Maintain functions even in such cold water Breathing underwater 0 Make breathing holes under ice so that they can come up for air Thermal Challenges for Marine Mammals Face this problem water has a really high heat conductance o This means that organisms constantly face a loss of body heat to the water Solutions to body heat loss 0 Three processes and adaptations we can observe Blubber 2 insulation in Lipid rich highly vascularized Can move blood to these sites fast 2 Thick up to 12 inches on some whales 2 Aids in buoyancy too Body sizes tend to be large surface area to volume ratio 2 Large animal smaller surface area to bigger body volume 2 Less surface area over which to lose heat and a larger volume to hold heat 2 Flippers and flukes are places for a lot of heat loss because of their smaller SAV ratio BUT they have Countercurrent heat exchangers in feet and flippers 2 Counters the small SAV ratio 2 Has a system that rotates blood in the flipper to keep it warm 2 Arterial blood will cool down as it nears the end of the extremity but then the venous blood will warm up as it returns 2 Lets some heat be recovered Foraging and diving 0 Use their adaptations to get into the water to feed 0 Diving 9 feeding Theres not much food at the surface 0 Set up by adaptations in the respiratory system Lecture 9 Ecophys of Marine Vertebrates 31014 921 AM Marine Mammals Foraging and champion divers of the Antarctic Amazing divers Diving response in marine mammals What happens 0 Extra oxygen storage myoglobin and hemoglobin Apnea suppression of breathing Bradycardia slowed heart rate Hypoperfusion Lactate washout at the end of a dive Recovery mode Weddell seal midwater foraging dive 0 3655 m deep 0 meandering descents don39t cost that much energy get really streamlined and glide put body in unusual form to be more resistant to drag 0 once they get to the bottom horizontal swimming exploration 0 on the bottom they look for octopus and also find fish on the way back up 0 dives take 1530 minutes review 0 not every dive results in a bunch of food and energy 0 they have the capacity to reduce their metabolic rate during dives 10 reduction Aerobic Dive Limit ADL mO2kgminute 20 min not go into huge metabolic debt how they shut down metabolism 0 profound bradycardia and vasoconstriction shunts blood away from periphery parts of body are used to hypoxia 0 blood flow and oxygen supplies are maintained to hypoxia sensitive tissues such as the brain 0 other parts of body get by on oxygen stores 0 these are regulated by hormonal responses penguins can hit deep depths at very short intervals OOOO 0 they are superb cardiovascularly 0 they have been observed to have heart rates as low as 6 beats per minute during a dive must have a brain tolerant to hypoxia 0 diving seals as dive initiates 2 lungs collapse 2 O2 transferred to spleen and muscles for storage Spleen holds a lot of oxygenated blood material 2 During dive 02 goes back to heart brain and muscles Has special circulatory adaptations to deliver these blood cells back into the circulatory system during a dive During a dive the lungs heart diaphragm pancreas liver have under perfusion less oxygen delivered Cold blood can also be shunted away from CCHE and appears to cool brain during a dive 2 Reduces demand for oxygen 25 Myoglobin O2 storage in muscles 0 Related to hemoglobin but located in the tissues 0 As the seals mature they start to produce more myoglobin 0 Mb storage 10x greater than most terrestrial animals 0 Myoglobin holds one third of oxygen stores in a Weddell seals body Leatherback Sea Turtle Tagged to determine what its doing Lecture 10 Intro to Freshwater Env 31014 921 AM Life at the land sea interface Two general regions 0 Shores dominated by tides tidal marshes wet lands mudflats beaches 0 Estuaries where rivers run into sea 0 These environments have a lot of variation mixing of salinity and environmental factors Organisms adapted to a dynamic environment Freshwater Salmon swimming upstream 0 Factors that influence them Less salinity as you go upstream Temperature Dissolved oxygen decreases as temp increases Predation Food sources Sediment input Turbidity NEW STRESS runoff pollution from land 2 Comes from agriculture sewage human waste 2 Nitrogen phosphorus hormones 2 Trophic transmission 9 bioaccumulation of these wastes Two Main Topics in Brackish environments Interfacing with varying aquatic environments 9 osmoregulation Changing oxygen level changes in the freshwater aquatic environment 0 Hypoxia Ex Dead zones algal blooms o Influences on performance Osmoregulation Homeostatic goal maintain balance of ions in internal body Challenges not losing ions to the external environment 0 Osmosis rules water moves into the organism and ions move out Need to find a way to regulate this 0 Water gain ion loss problem Organisms have a varying degree of hyper regulation 2 River mussel osmoconformer cant regulate 2 Migrating fish can regulate 2 Chinese mitten crab very good regulator Freshwater invertebrates 0 Water gain and loss of ions 0 Gill blessing and curse Has increased surface area for feeding but gives a bigger surface for osmosis 0 Solution has been to form a really dilute urine Pee out water but not solutes 9 retain ions Have specialized kidneys 2 Really good at concentrating 0 First seen in flame cell in planaria 0 Pumps out water Why do we care about physiology of these organisms Because rusty crayfish Chinese mitten crab and zebra mussels are all invaders into freshwater ecosystems o Invasive species problem 9 need to understand how it competes with native species Does physiological capacity of invading species contribute to its success o Ex Results from coccia study Invasive TVV vs native SL in Spain TVV originally from US has not become the dominant species in some saline wetlands in Spain Wanted to study if the Ecophysiology of this alien species favors its spread in the Iberian Peninsula and its relative success in saline areas Compared native species and invading species to conditions of varying temperatures and salinities It was found that the native species appeared to have a broader thermal range and could thus outperform the invading species BUT TVVs acclimated to higher temperatures could have a higher CTmax that natives Conclusions while the native species has a broader thermal range the invader performs well at high salinities and temperatures and this ability may facilitate invasion in Mediterranean areas has greater plasticity can respond to climate shits better Chinese mitten crab 0 Found in California 0 Has spread throughout central California started in San Francisco bay 0 Its probably human driven because of our ports and agriculture San Fran port has so many invasive species because its so used commercially o What exactly will it do to California water ways 0 ASSIGNMENT prepare an impact statement on the impact of the crab on the San Fran Bay and a way to fix it Lecture 11 Osmoregulation 31014 921 AM Fish Osmoregulation The ability for a fish to osmoregulate is incredible o Telost fish can regulate below the osmolarity of the ocean Strong selection pressure to reduce osmotic gradient Osmotic Gradients in Both Aquatic Environments Freshwater 0 Higher concentration of solutes in cells relative to external environment 0 Lower concentration of water in cells relative to external environment Marine 0 Lower concentration of solutes in cells relative to external environment 0 Higher concentration of water in cells relative to external environment Solutions to fix this AA 0 Minimize cellular interaction with the external environment But fish cant be water proof because they have to breathe 0 Oxygen is extracted from water and needed to fuel metabolism and maintain cell function o Gills are the major respiratory organ in fish Fish gills evolved to maximize oxygen exchange 0 Extremely high surface area Kind of like human intestines villi microvilli 0 Extremely high permeability 0 Direct contact with the external environment o HOWEVER if water can be exchanged so can water and small ions Surface area to volume revisited More surface area to less volume good for gas exchange bad for osmoregulation Less surface area and more volume bad for gas exchange but good for osmoregulation 0 Need to offset the movement of ions and water by passive diffusion Freshwater expel excess water through extremely dilute urine 2 Absorb solutes through gills Marine drink ocean water to get more water 2 Excrete solutes through gills U HAVE SAME STRUCTURES but work in the opposite directions Take home messages An evolutionary history in freshwater has caused an osmotic gradient to exist in teleost fish in both marine and freshwater environments These gradients cause water and ions to move passively across cell membranes by diffusion To maintain water balance freshwater teleost excrete extremely dilute urine and marine teleost drink seawater To maintain ionic balance freshwater fish absorb solutes through gills and marine excrete solutes through gills Lecture 12 Salmon Migration 31014 921 AM Freshwater Ecological physiology of migrating salmon Part one the environment 0 Impacts of multiple environmental factors on salmon physiology Salmon life cycles Salinity Temperature Migration distance Part two case study 0 Monitoring physiological performance in migrating salmon Environment Salmon life cycles Eggs are hatched into fresh water lakes rivers The move into marine water oceans as they are growing They return to fresh water as adults to lay their eggs Transition from ocean feeding grounds to freshwater spawning grounds is most challenging phase of salmon life cycles Salinity 2 Moving between marine and freshwater environments 2 Osmotic gradients switch 2 Salmon are teleosts Temperature 2 Ocean is cold 2 Rivers and lakes are warm Migration distance 2 Some populations swim 1500km to reach spawning areas 2 Swim upstream Salinity and osmoregulation 0 They are teloests osmotic gradient between cells and the environment Spawning phase freshwater 2 Ions out passive ions in active 2 Water in passive water out active OOOO Growth phase El El Ions out Water in active ions in passive active water out passive 0 Have to adapt to a complete reversal of salinity 0 HOW 1 Preparation El migration is triggered by seasonal changes in day length migration salmon know a salinity change is coming change the activity and abundance of ion transporting proteins prior to reaching freshwater preparatory changes in NaKATPase activity as they move from ocean to freshwater activity decreases 2 Modify behavior El sample water with lower salinity by holding in the estuary and moving between areas of differing salinity 0 have to adapt to temperature changes in temperature have major impacts on cell func on 0 how El El El El raises metabolic rate alters membrane function enzyme activities protein structure 1 Adjust migration timing El different populations migrate at different times of the year populations with highest temperature tolerance migrate during summer when river temps are warmest populations with less temperature tolerance migrate in spring and fall when river temps are cooler in the context of global climate change 2 longer duration heat waves 2 more extreme heat events 2 rise in average temperatures 2 warming trend expected to continue in the future 2 this creates a mismatch between run timing and temperature tolerance 2 serious trouble salmon in California occupy the southern most regions of salmon distributions making their freshwater habitats more prone to warming 20 of californias 31 salmon taxa are in danger of extinction within 100 years 0 Migration distance Some salmon are incredible endurance swimmers some are not Short vs long distance migrators 2 Salmon with long distance migrations Higher energy levels when migration begins Fewer eggs 0 More streamline morphology More efficient energy utilization Longer sustained swimming 2 Short distance migrations Lower energy at start of migration More eggs Less streamline morphology Less efficient energy utilization Shorter sustained swimming Case study monitoring physiological performance in migrating salmon Not all salmon complete migration many die Why 0 Compare the physiological parameters between successful migrants and pre mature mortalities Those fish that died on the way to the spawning grounds 2 1 higher levels of stress indicators in their blood elevated plasma lactate elevated glucose higher energy demands elevated cortisol stress hormone controlling various pathways 2 2 osmoregularity problems elevated plasma osmolality reduced Na concentrations 2 3 lower levels of reproductive hormones reduced testosterone in males reduced 11 keto testosterone in females Salmon are important Ecologically o Considered keystone species in marine freshwater and riparian ecosystems Economically 0 Commercial and recreational fisheries generate over billions annually and support many jobs Culturally o Integral to mythology spiritual integrity and livelihoods of coastal first nations Lecture 13 Salmon Migration II 31014 921 AM Salmon Migration The freshwater environment what are the stresses 0 Respiratory adaptation and challenges in freshwater Driven by high variability of oxygen levels in freshwater habitats o Solubility of oxygen in water Normoxic a good level of oxygen in water for animals Hypoxia less than normal oxygen Anoxic no oxygen As you increase temperatures in water the amount of dissolved oxygen in water decreases Salmon probably go from 15C 25C which equates to a 13 mLliter difference of dissolved 02 into the water 0 There are huge variabilities with oxygen levels in freshwater environments A lake surface depth 810 Estuary 16 Grass swamp 2 12 stock pond 0 2 all of these environments vary because of how the plants and algae interact 2 some pond water can go completely anoxic at night because of the dark reactions of plants at night 0 how do temperature and oxygen levels interact in the environment to affect animal performance Aquatic surface respiration ASR in fish head to the surface 2 When water reaches a critical hypoxic level even non air breathing fish will go to the surface in order to get oxygen Species differences 2 Hypoxia tolerant fish Goldfish carp are very tolerant 0 O2 crit 18 mL O2L El 0 Also European freshwater eel tilapia coral reef fish are good at low oxygen levels However salmon are not that tolerant of low oxygen levels 0 O2 crit 6mL O2L 0 Respiratory adaptation and challenges in freshwater Eliason paper El Local adaptation of salmon to the place that they migrate Fine tuning of physiology has a genetic basis Has long term data for warming of Hells Gate river Found that the Fraser river is warming almost 2C warming over last 60 years Compared 6 populations of stockeye salmon groups of fish that migrated to different places Weaver coastal group that doesn39t migrate very far Early stuart longest migration into the warmest water Hypothesis if a fish is going to succeed in migration there has to be a cardiovascular physiology component to this Are there performance changes that correlate to the intensity of the migration Cardiovascular physiology El Gas exchange involves 4 basic steps 1 Breathing movements continual supply of air or fluid 0 breathing faster trying to bring in more air 2 Diffusion 02 and CO2 across respiratory epithelium 3 Bulk transport blood transports gases 0 can have more cells to transport oxygen 4 Diffusion 02 and CO2 across capillary walls between blood and mitochondria in tissue cells 0 building more capillaries makes more aerobically fit delivery of oxygen to the tissue in a water breathing teleost gills take in air which oxygenates blood blood goes to tissues 9 deoxygenated blood returns to heart to get pumped gets breathed out of the gills cardiac output as heart performance cardiac output stroke volume x heart rate can increase amount of blood pumped instead of increasing number of blood cells to increase performance measured in mLmin what they found fish that migrated farther had a biggest ventricular mass heart is a more powerful pump increased SV also had better blood flow to the myocardium a better pump Aerobic scope El El Defined as maximal sustain metabolic rateBMR Metabolic activity can increase 1015 fold in some species How much over resting can you increase the use ofoxygen In salmon aerobic scope can be 5 for smaller fish but around 15 for migrating adults Some fish couldn39t swim at higher temperatures Upriver fish have greater aerobic scope Weaver had lowest aerobic scope and early stuart had highest Local adaptation Lecture 14 Ecophys of Caves 31014 921 AM Caves Life in Darkness Biospeleology the study of organisms that live in caves Cave organisms share a set of physiological traits Those organisms inhabiting the areas furthest from an entry point have evolved a set of physiological adaptations for life in the dark Cave zones 0 Entrance zone sunlight variable temperatures green vegetation 0 Twilight zone less light minor temperatures changes minimal plant life 0 Dark zone no light constant temperature Convergent evolution in caves Convergent evolution process whereby organisms not closely related independently evolve similar traits are a result of having to adapt to similar environment or ecological niches Cave organisms use similar evolutionary solutions to the problems associated with living life in a cave 0 Two main problems 1 ABSENCE OF LIGHT 2 reduction of eyes 392 reduction of pigment 2 SCARCITY OF FOOD 2 increased food finding ability starvation resistance lowered metabolic rate lowered fecundity El El El Adaptations to problems 1 absence of light 0 loss or reduction of eyes is there an advantage to not having eyes CASE STUDY the Mexican Tetra 2 This species have surface and cave dwelling forms of the same species Cave fish eyes and pigmentation absent Surface fish large eyes and pigmentation D But early eye development is conserved between cave and surface fish but at some point they come to a divergence 2 The candidate gene approach researchers wanted to find the genes that are expressed to promote this differentiation Found that the SHH gene is expanded in the cave fish forebrain When the amount of SHH is reduced in cave fish they start to grow eyes When the amount is increased in surface fish they have no eyes SHH also controls other areas of development 0 Found that its expanded expression in cavefish also increases the number of taste buds and chemoreceptors around the lower jaw Easier to find food in total darkness Changes in brain development may also be linked to other cave dwelling traits 0 Loss of shoaling behavior 0 Loss of aggression 0 Enhanced olfaction 2 Loss of eyes and pigment was a result of natural selection Was a consequence of evolution selecting for other traits that enhanced physiological performance in caves Is there an advantage to not having eyes YES 0 Loss or reduction of pigment In surface dwelling animals pigmentation is used for protection from sunlight camouflage mimicry and species and sex recognition all of which are irrelevant in the dark cave environment May be related to selection for behavioral changes 2 Loss of melanin in the cave fish results in no pigmentation 2 But there is also an increase of dopamine which leads to behavioral changes loss of shoaling loss of aggression o Circadian rhythms Abolished in cave salamander 2 Cave habitat is missing the external cues that drive circadian rhythms photoperiod temperature 2 Scarcity of food 0 food is unpredictable in cave ecosystems no light no photosynthesis input of nutrients depend upon external sources wind rainwater feces 0 lack of food in caves has driven physiological adaptations in cave organisms increased food finding ability 2 EX Crayfish and beetles In the cave these organisms have elongated appendages that allow organisms to cover more area while searching for food starvation resistance 2 cave fish are better adapted to starvation 2 cavefish lose less mass and use less fat during starvation reduced metabolic rates 2 CASE STUDY surface and cave salamanders Facultative cave dweller will regularly move into caves but not persist in these habitats Obligate cave dweller lives exclusively in cave habitats When cave salamanders search for food they expend less energy than the surface salamanders and also have an extreme metabolic depression in times of starvation reduced fecundity 2 surface beetle many eggs 9 feeding larvae 9 pupa 9 adult 2 French cave beetle single large egg whuge amounts of yolk 9 non feeding larvae uses yolk for energy 9 pupa 9 adult only feeding stage Take home messages Organisms that inhabit caves share a set of physiological adaptations This is an excellent example of convergent evolution Two main factors drive physiological adaptations in cave ecosystems o 1 absence of light loss of eyes cavefish and hedgehog gene loss of pigmentation cave fish and tyrosine pathway 0 2 scarcity of food increase food finding ability elongated appendages starvation resistance cave fish during starvation reduced metabolic rate cave salamanders reduced fecundity French cave beetle Study Guide Exam 2 31014 921 AM Study Guide Physiological Challenges in Marine Vertebrates What challenges are faced by homoeothermic marine vertebrates o These animals are very susceptible to constant and rapid loss of body heat because water has very high heat conductance 0 They deal with this in three main ways bubber 2 lipid rich highly vascularized 2 can get blood here really quickly body sizes tend to be large surface area to volume ratios 2 when bodies are bigger there is more volume that retains heat than surface area to release it countercurrent heat exchangers in feet and flippers What is meant by secondary invasion of the sea 0 What is a countercurrent heat exchanger CCHE Sketch one in an animal 0 These occur in feet or flippers It is a system of keeping the blood warm When arterial blood comes to the tip of the foot it is very warm Instead of losing this heat to the environment it transfers it to the venous blood in order to minimize heat loss This is a much more efficient method because it requires less pumping of blood by the heart and less overall heat loss What is the diving response What are the key features of this response 0 The diving response is a reflex in mammals that optimizes respiration to allow staying underwater for extended periods of time Certain changes in an organisms functions occur in order to promote this reflex such as Extra oxygen storage 2 Have more myoglobin and hemoglobin that allow them to bind more oxygen 392 Myoglobin has incredible oxygen binding abilities Apnoea 2 Breathing is suppressed and metabolic rate can decrease to 10 of their pre dive values Bradycardia 2 Slowed heart rate and vasoconstriction shunts blood away from the periphery 2 Helps in decreasing metabolic rate Hypoperfusion 2 Blood is directed away from less necessary organs such as the pancreas liver diaphragm 2 Still directs blood to brain retina lungs because they are necessary for diving 2 Many organs are used to hypoxia Lactate washout Calculate surface to volume ratios for two cubes 1m vs 10m side lengths 0 Surface area 1m 6 volume 1m 1 ratio 6 0 Surface area 10m 600 volume 1000 ratio 6 What are the trade offs regarding hypoperfusion the shunting of blood away from other organs and to vital organs such as muscle and brain Why do this 0 As dive initiates lungs start to collapse 02 is transferred to the spleen and muscles for storage and then during the dive O2 is released to heart brain and muscles 0 This means some organs don39t get as much blood 02 so they have to become tolerant to hypoxia Physiological Challenges in Freshwater How does the nature of the thermal environment compare with that of the open ocean o In estuaries and shores the temperature can change very rapidly compared to in the open ocean What challenges are faced by freshwater organisms 0 These organisms face many challenges including Salinity changes 2 In freshwater organisms gain a lot of water from the environment but also lose many ions Temperature changes Oxygen content changes Turbidity Runoff pollution What is a freshwater kidney A flame cell 0 The freshwater kidney is responsible for maintaining as many internal ions as possible while also expelling out excess water They do this by creating very dilute urine to prevent the unnecessary loss of any ions A flame cell is thought to be one of the first excretory systems in some invertebrates It is a hollow cell that is responsible for urine output and maintain ionic regulation Understand the change in dissolved oxygen as water temperature changes 0 Oxygen content decreases in water as the temperature rises How do temperature and oxygen levels interact in the environment to affect animal performance 0 Animals can39t breathe as well in warm water so they initiate Aquatic Surface Respiration ASR swim to the surface Osmoregulation in Marine Fish What are the tradeoffs that fish face with regard to having to do gas exchange in water 0 Fish gills are designed to have a very high surface area high permeability and direct contact with the external environment in order to maximize gas exchange However these characteristics also cause a problem in osmoregulation because if oxygen can be easily exchanged across the gills that means so can other ions and molecules How does movement of ions and water vary in a freshwater fish vs a marine fish 0 In freshwater when water comes in many ions go out In marine water when the gill is opened up for diffusion it is actually ions that move in and water that moves out What is meant by osmoregulation How does osmotic concentration compare in a mussel vs a marine fish 0 Osmoregulation refers to the maintenance of ionic composition inside of the body of an organism Organisms need to offset the unfavorable movement of ions and water that occur due to passive diffusion by utilizing active transport to get things where they need to be This occurs in freshwater fish by actively expelling excess water by creating extremely dilute urine and also actively importing ions into their body Marine fish have contrasting roles and actually actively export ions while uptaking water into their bodies What is a chloride cell What is its physiological role 0 Chloride cells are cells that assist in the movement of salts or ions In freshwater fish they assist by actively absorbing water into the body In marine fish they assist by actively excreting solutes to the outside environment to maintain osmotic balance Discuss the role of surface area hint SAV ratio in a fish gill Draw an example 0 In gills with more surface area and less volume this is good for gas exchange because the oxygen can reach all parts of the gill However this is bad for osmoregulation because it also means the ions have more space to either enter or leave the gill The opposite is true for gills with more surface and less volume This arrangement is beneficial for osmoregulation but bad for gas exchange Salmon Migration What abiotic challenges are faced by migrating salmon o Salinity Moving between marine and freshwater habitats Osmotic gradients switch Salmon are teleosts osmotic gradient between cells and environment 0 Temperature Ocean is cold Rivers and lakes are warm 0 Migration distance Some populations migrate 1500km to reach spawning areas Have to swim upstream against current How do migrating salmon prepare for the large change in salinity associated with fresh water entry 0 Migrating salmon have to adopt to a complete reversal of salinity freshwater vs marine osmoregulation techniques To do so salmon prepare in two ways 1 Salmon know that a salinity change is coming based on seasonal changes they can observe To prepare for this they change the activity and abundance of ion transporting proteins prior to reaching freshwater As they move from ocean to fresh water NaK ATPase activity in pumps decreases in order to maintain ionic balance after being in freshwater 2 Salmon modify their behavior to deal with the changing salinity They will sample water with lower salinity by staying in the estuary and moving between areas of varying salinity This allows their bodies to transition more seamlessly How do migrating salmon deal with temperature stress 0 Temperature stresses have major impacts in salmon cell function including raises metabolic rate alters membrane function alters enzyme activities and protein structure To account for these changes salmon have some coping strategies Some populations will migrate at different times of the year so that those populations with the highest temperature tolerance migrate at the warmest times of the year How does run timing relate to thermal tolerance and global warming 0 Global warming results in longer duration heat waves more extreme heat events and a rise in average temperatures This type of warming creates a mismatch between run timing and temperature tolerance Fewer populations will be able to tolerate the high temperatures and not be able to complete runs in the hottest summer months What are the characteristics of long distance vs short distance migrators 0 Salmon with long distance migrations Higher energy levels when migration begins Produce fewer eggs Have a more streamline morphology Have more efficient energy utilization Can sustain longer swimming 0 Shorter distance migrations Lower energy at beginning of migration More eggs Less streamline morphology Less efficient energy utilization Shorter sustained swimming Thermal Stress in Freshwater Environments Sockeye Salmon Migration and Local Adaptation Describe the temperature variation in the drainages of the Fraser River 0 The Fraser River is warming increasing 19 C in the last 60 years What are the populations of interest in the sockeye salmon study 0 The populations of interest are Weaver coastal group that doesn39t migrate very far and Early Stuart longest migration into the warmest water Do the populations experience different temperatures How does migration intensity vary for the different drainages 0 Yes the populations experienced various temperatures It was found that some fish couldn39t even swim at such high temperatures For organisms that reach a temperature above their Topt it has been found that their aerobic scope and cardiac output start to decrease What properties of cardiac performance changed in the different populations 0 Among the different populations aerobic scope and cardiac output changed with respect to migration differences Aerobic scope is defined as maximal sustained metabolic ratebasal metabolic rate It was found that fish who swam upriver and had longer migration distances frequently had a better aerobic scope and also had a heart that functioned as a better pump How is this an example of local adaptation o This is an example of local adaptation because the fish that are in environments that have tougher conditions such as swimming upriver higher temperatures or require longer migration distances are the populations that have evolved a better aerobic scope and a more efficient heart pump Ecophysiology of Life in a Cave What are the two main problems regarding life in a cave that we discussed 0 Absence of light 0 Scarcity of food Overview the story regarding eye development in cave fish 0 What Cave fish do not have eyes but their surface relatives do It has been observed that eye development is conserved up to a certain point in cave and surface fish Researchers used this knowledge to come up with a list of genes that are known to be expressed during this period of fish development and in the area of developing eyes They found that the expression of the Shh gene is expanded in the cavefish When they reduced the Shh expression in cave fish they grew eyes and when they increased the level of Shh in surface fish they didn39t have eyes Shh also controls brain development which may be linked to other cave dwelling traits such as loss of shoaling behavior loss of aggression and enhanced olfaction mechanism accounts for the loss of pigmentation in cave fish In surface dwelling animals pigmentation is used for protection form sunlight camouflage mimicry and species and sex recognition all of which are irrelevant in dark caves There is a mechanism that gives fish their pigmentation and also behavioral attributes Tyrosine 9 dopamine and melanin production Dopamine is responsible for behavior and melanin for pigment Since cave fish don39t need melanin tyrosine directs all of its efforts to making more dopamine which results in behavior such as loss of shoaling and loss of aggression Describe 4 physiological adaptations for life in a cave in response to food scarcity o 1 increased food finding ability in crayfish and beetles they have elongated appendages which allow them to cover more area when searching for food 0 2 starvation resistance cave fish are better adapted to starvation and loss less mass and use less fat during starvation o 3 reduced metabolic rates surface salamanders have a much higher metabolic rate than cave salamanders o 4 reduced fecundity surface beetles will produce multiple eggs and larvae than cave beetles which only produce one Introduction to Global Change Biology What is global change biology 0 Global change biology examines the possible reactions species may have to global warming What are the three responses that populations or organisms might make to a global change 0 Geographic range shifts o Acclimatization o Adaptation o Extinction Lecture 15 Intro to Climate Change 31014 921 AM Climate change biology Species responses to a changing environment Biological responses to global change 0 Geographic range shifts o Acclimatization o Adaptation o Extinction Expected Range Shifts Poleward 0 Very common in response to climate change 0 Earth has very strong latitudinal gradients in temperatures 0 As portions of species ranges get hotter species respond by shifting biogeographic ranges poleward to more suitable temperatures 0 Meta analysis confirms many species moving polewards ID d 129 species whose ranges had shifted between 19202010 Surveyed a large range of different types of organisms 75 of range shifts were in the poleward direction in 70 of cases climate change was identified as primary driver moved an average of 19km per year 0 in the past few decades Kelletii Kelletii substantially extended its range northward past its historic limit at Point Conception northern limit is currently Monterey Bay accounting to a 325km extension of its range 2 presence here first only observed 30 years ago K Kelletii populations are now occurring at the northern limits of their range and are persisting Juveniles appear at the northern most boundary of this species range indicating that the population is stable for the time being 0 for fish climate change strongly influences distribution and abundance through changes in growth survival reproduction or responses to changes at other trophic levels these changes affect the nature and value of commercial fisheries a recent study found that 15 of 36 of species investigated shifted their center of abundance in the north sea since 1977 2 North Sea has warmed 1 C since 1977 2 most of these species shifted northward response to climate change same studie also found that fish were moving deeper in the water to escape elevated sea surface temperatures 2 six species moved deeper with warming but did not change in latitude 2 move into deeper cooler water to maintain optimal temperature 0 Hopkins Marine Station of Stanford university in Monterey Bay In 1931 researches conducted a survey of the organisms comprising the intertidal Re survey showed shifts in distributions of benthic marine invertebrates Upward in elevation Consequences of Range Shifts 1 squeeze effects 0 arise when abiotic stress shifts at the vertical range of a species into the vertical range of a competitor essentially leaving species no where to go illustrate how range shifts can alter ecosystem dynamics 0 these are especially important consequences in the intertidal zone EX the barnacle is excluded from moving to a lower location to avoid high temperatures because a competitor lives at that lower level 2 Rather than have a range shift their current range is simply being squeezed from above heat and from below predator o EX upper limit of mussels in intertidal determined by temperature lower limit determined by predation by the sea star warmer temperatures increase predation rates in sea star more mussels will be preyed upon in future climates mussels will be squeezed from above by temperature and below by increased predation 2 stress at range boundaries 0 where ranges are being squeezed a larger portion of the population will inhabit the very edge of its range 0 studies have shown that range edges are more stressful and thus support fewer individuals show higher levels of HSP70 heat stress protein at edge of range 3 species invasions o typically view species invasions are the results of long distance transport by humans 0 but even relatively slower shifts due to climate change can be considered invasions 0 not all members of a community shift at the same time or at the same speed 0 result is species invading new habitats which disrupts ecosystem function ex As NE pacific natives move north they push into different marine communities which disrupts these ecosystems ex The invasion of Georgia the Carolinas and Chesapeake Bay by tropical and subtropical species native to the Caribbean 2 species are moving north to escape the heat 2 this is pushing into other organisms territories 4 economic impacts 0 ex Fisheries and herring in Norway herring are economically valuable fish in Norway these fish have been moving farther north to escape warming temperatures many herrings stocks are now in international waters rather than waters controlled by Norway Norway can no longer regulated the catch of herring 5 conservation strategies 0 ex Leatherback sea turtles critically endangered species in the Atlantic upper boundary was limited by the 15 C isotherm this boundary has shifted northward allowing turtles to inhabit these areas but population is not growing and now have to conserve same number of turtles over a larger geographic area Similar trends in terrestrial organisms Terrestrial organisms have another option moving to higher elevation o Cooler temperatures at higher altitudes Yes and 2 3x faster thane expected 0 Meta analysis confirms many species moving poleward AND to higher elevation Poleward 17km per decade Altitudinal 11m per decade 0 1 latitudinal poleward range shifts in terrestrial environments 0 winter range shifts in North American birds many north American birds follow a regular seasonal migration patter moving north to feed and breed in the summer then moving south to spend the winter in warmer areas 0 a century of warming in the US rising temperatures indicate northern areas much warmer than before 2 average air temperatures change in different parts of the United States since the early 20 century 0 migrating birds are moving further north poleward among 305 widespread North American bird species moved their center of abundance northward between 1966 to 2005 in mid December to January the average species shifted north by 35 miles during this species 2 two species moved more than 400 miles northward EX purple finch 2 they are not migrating as far south relative to historical average 2 center of abundance has shifted 433 miles north in the last 40 years EX wild turkey 2 Ability to thrive in human influenced landscapes have increased the wild turkey populations throughout its range in the last 40 years 2 Over 400 miles or northward movement over the same period Because similar range shifts are occurring in such a wide range of birds with very different lifestyles strong suggests warming temperatures are the primary cause Migrating birds are moving further north poleward 2 Example of citizen science 2 Data has been collected as part of National Audobon Society39s Annual Christmas Bird Count Has been running for 113 years Involving public as scientists to gather data over a much larger area than they could get themselves 2 Citizens have noticed that birds are not as far south as they have normally been in the past 0 2 altitudinal range shifts in terrestrial environments 0 eg Small mammal distributions in Yosemite National Park resampled along a transect previously sampled 1916 1920 compared current day animal abundances with that from 1920 along an altitudinal gradient from 60 to 3300m above sealevel substantial upward changes in elevation limits for 14 of 28 species monitored upward shifts were 500m on average life history and ecological traits were weak predictors likely due to climate low elevation species expanded ranges upward 2 eg California pocket mouse pinyon mouse 0 trapped at the top Are alpine species more vulnerable eg Long tailed vole 2 lower boundary 614m higher but upper boundary unchanged eg Bushy tailed wood rate 2 lower boundary 609m higher but upper boundary unchanged eg North American Pika 2 spend their entire lives in cold alpine terrain 2 cold adapted species can over heat at temperatures as low as 78C 2 recently disappeared from 8 of 25 mountainous locations in the Rocky and Sierra Nevada mountains where they were documented in the early 1900s 2 attributed loss of suitable habitat 2 no where to migrate to escape further warming same as squeeze effects in the intertidal 2 lack of habitat prevents alpine species from moving to higher elevations 2 lower elevations are too hot 2 being squeezed just like organisms in the high intertidal Phenology Seasonal timing of life events in plants and animals Processes are triggered by environmental cues Organisms are adapted to cues in their habitat o What happens when the cues change Biological consequences of phenological shifts o Hibernation 0 Food Yellow bellied marmots live in the rocky mountains and are known to be hibernators and herbivores 2 Dependent on abundance of plant food to replenish the weight lost during hibernation Skinny in the spring chubby in the fall In 2000 marmots in Colorado are emerging 38 days earlier than 23 years ago apparently in response to warming spring air temperatures Despite warmer temperatures snow is often not melted and plant food sources remain covered in snow and inaccessible to the marmots However recently marmots in the Rockies are experiencing a baby boom Think that moms are emerging earlier and getting food earlier 9 more babies 2 Good for the population Unless all components of food chain are shifting at the same rate there is going to be a mismatch in the timing of important events Migrating salmon as a food source migration changes will alter food availability for predators One of the best studied phenologies is the Oak Winter Moth moth vs Great Tit bird interaction in Europe 2 The bird Great Tit is dependent on the appearance of food at the right time of the year Lay eggs during spring so that hatching coincides with peak abundance of winter moth caterpillars This timing ensures that newly hatched chicks will have adequate food supply 2 In turn winter moth caterpillars are dependent upon new buds from the oak tree for its food 2 In the Netherlands peak availability of insects used to feed chicks now occurs nine days earlier than in the past Unfortunately great tits have not responded by altering their reproductive timing 2 The result is a mismatch between the time of peak availability of insects and the peak food depends of nestling Great Tits 2 Earlier emergence of Winter moth caterpillars is not good for caterpillars wither Now emerge before bud burst in oak tree Winter moth caterpillars feed on new buds and those that are forced to eat older buds have reduced fitness 0 Pollination Lecture 16 Ocean Acidification 31014 921 AM Ocean acidification pH scale 0 the concentration of HH30 ions in an aqueous solution pure water is neutral pH7 2 1 x 10 7 moles of OH and H 2 pH ogH a log scale 2 pH6 has 10x more H ions than pH7 physiological pH 0 cell membranes keep H in or out depending on the needs of the cell but theyre not perfect o intracellular usually about 74 for most cells human blood 735745 seawater is slightly more alkaline than blood 0 extracellular can vary greatly cells can tolerate and manipulate different extracellular environments 0 regulation lipid bilayer is impermeable to H ions the way H ions get in and out is through 2 transporter molecules transmembrane proteins form a chanel that selectively allows ions to pass in and out transmembrane proteins can use active or passive diffusion to allow ions in and out o passive follow the H gradient 0 active use ATP to pump H against the gradient 0 part of osmoregulation marine organisms generally want to keep H in their cells and fluids 2 usually are actively pumping out ions 2 ocean is a little too alkaline for them so they keep H inside some tissues are more permeable than others 2 gills mucous membranes 0 Biochemical effects of pH Affects hydrogen bonding 2 Protein secondary and tertiary structure Digestive activities 2 Low pH in extracellular space or intracellular vacuoles 2 Disrupts protein structure of foods Osmotic gradients 2 Mitochondria and proton motive force makes ATP using H gradient Impact of Global change CO2 emissions into the atmosphere get directly absorbed into the ocean 0 CO2 is highly water soluble 0 CO2 in the surface ocean is in equilibrium with the atmosphere 0 Dissolved CO2 as partial pressure of gas pCO2 The imprint of global change 0 Oceans are also warming 0 Warmer temperatures lower average pH double whammy So far we have more research done on temperature change than pH change Carbonate Chemistry 3H20 CD2 H20 H30 HCO3 o Bicarbonate 2H30 C032 0 carbonate can interchange between all three of these states what we measure 0 pH from these H30 ions pCO2 from amount of CO2 total alkalinity total dissolved carbon all of these measurements are related but measurable independently by different techniques OOOO Temperature and Pressure CO2 in water behaves differently at low temperature 0 More gas can dissolve at lower temperatures Polar regions Deep ocean and higher pressures 0 also more can dissolve 0 state changes gas or liquid to solid hydrate occur Natural sources of variation in CO2 Geo tectonic activity Respiration o Photosynthesis vs respiration There is a balance between these two in shallower waters 0 Deep water Upwelling brings high CO2 water from depth to surface No CO2 taken up by photosynthetic organisms more C02 0 Highly dynamic coastal systems Coral reefs Estuaries Kelp forests Tidepools Night and day have different pHs because of respiration occurring all the time and photosynthesis only occurring during the day Anthropogenic CO2 added to the natural environment Pushes annual osciallation levels of the CO2 in the ocean past to where they currently lie Components of CO2 in biochemistry and physiology C02 0 Respiration Converting CO2 into CO32 as a buffer Also actively excreting through gills extra carbon dioxide 0 HCO3 Acid base homeostasis Respiration Biomineralization 0 C032 Biomineralization Acid base homeostatsis Calcium Carbonate CaCO3 0 Main structural mineral of marine life forms Aragonite and calcite 1gt omega more dissociation o happens with more CO2 dissolved 0 high pCO2 0 low pH 0 lower temp 1lt omega more CaCO3 Biominieralization physiology Approaches to the study of Ecophysiology 0 Natural gradients Latitudinal Altitudinal Bathymetric Point soure diffusion 0 Experimental Acclimation Adaptation Case study 1 natural laboratories Natural CO2 venting underwater form the Earth39s crust 0 Italy Mexico Papua New Guinea Varied pH levels when close to a C02 venting area Case Study 2 adaptive evolution Coccolithophores o Photosynthetic calcifiers o Ubiquitous in the surface open ocean o Blooms visible by satellite 0 Can be cultured in lab Experimental evolution 0 Comparing organisms that have not experienced selection simultaneously with those that have 0 E huxleyi can adapt to higher CO2 concentrations over many generations Lecture 17 Disease Ecophysiology 31014 921 AM Global Climate Change and Infectious Diseases What is an infectious disease 0 A microorganism causes this type of disease How is climate change going to impact the spread of infectious dieases 0 Have to understand changes in host and changes in pathogen due to changes in climate factors 0 These things change simultaneously Vector Borne Disease VBD Disease transmitted by another organism ex Mosquito 0 Ex Malaria Dengue fever West Nile Virus Elephantitis Complicated because of the extra element host disease VECTOR 0 Once vector is exposed to a disease it has to go through a series of changes extrinsic incubation factor before it can transmit disease 0 There is also an intrinsic incubation period that happens in the human before a vector can actually pick up the disease from the human Malaria and Dengue Fever 0 Scourges of large parts of the world and arguably vector borne disease that impact the most people 0 Hypothesis a widening of the tropical climatic belt that has been suggest to facilitate the expansion of tropical and subtropical disease 0 There are a lot of different species of protozoa that can cause malaria pasmodium Its transmitted by mosquitos Infects human RBCs Flourishes in the tropics and temperate regions Numbers have been changing worldwide 0 Malaria life cycle Mosquito eats blood meal parasite injected to host Asexual reproduction inside the host Host infects RBCs Mosquitos picks up a parasite with a blood meal from original host Development in the mosquito More transmission to hostsmosquitoshostsect 0 Pathology Fever episodes 104 106 F Malaise muscle pain Intense chill Nausea vomiting delirium Sweating indicates end of current paroxysm Busted RBC 9 Anemia Temperature affects o Extrinsic incubation o Bite rate 0 Development time 540 days total 14 days in water 0 Thermal optimum How will this change mosquitos adapt quickly Malaria and Kutch India 0 Tropical south Atlantic sea surface temperature warming 9 climate change and monsoonal rainfall drive malaria outbreaks 0 As temperatures rise the monsoon patterns change 0 Oceanography drives rainfall which drives disease outbreak o This changes malaria outbreaks in these parts and can even intensify these outbreaks Dengue Fever Transmitted by mosquitos it39s a virus Has been steadily increasing in number of cases over the years Infects the white blood cells Extrinsic incubation period 810 days Intrinsic 57 days There is a vaccine but there are 4 different subtypes that make it difficult 0 They are similarly related enough that it makes the vaccine less effective Can develop Dengue Hemorrhagic Fever because cells start to break and fevers increase a lot and eventually go into shock o A secondary dengue infection by a strain different from the first infection can cause DHF or DSS Modeling to forecast increase of disease 0 There is a mosquito that can carry dengue fever that is an invasive species in the US so it is possible that an individual with dengue fever could infect the US Project found that in the US warming both increased mosquito range northwards and shortened mosquito lifespans in the south limiting incubation of the disease at the southern end of the range 0 Findings indicate that climate change could impair as well as enhance disease transmission Sea Star Wasting Syndrome Has spread down the coast Started in June 2013 BC SB by Nov 2013 spreads fast By the time its noticed that an organism is infected it will die within 12 days Main concern comes from the fact that39s its moving N 9 S 0 Usually diseases are caused by warm water moves S 9 N o This is completely the opposite trend of normal 0 What could be driving this disease southward Lecture 18 0A in the Deep Sea 31014 921 AM Ocean Acidification in the Deep Sea Lecture 19 Intro to Terrestrial Systems 31014 921 AM Intro to Terrestrial Systems Transition to Land 0 New problems and some advantages to life on land 0 Groups of animals that have made the transition 0 Paths to terrestriality o Stresses A short list of land animals 0 Worms Mollusks Arthropods Vertebrates What39s missing Three paths to land 0 Marine origins already could deal with water loss due to high salinity environment 0 Freshwater origins difficult evolutionary transition due to hypotonic urine formation but 0 Sediment living adaptions to water and oxygen stress evolved here to some extent New medium how is it different 0 Advantages Air much less viscous as compared to water 2 Animal locomotion approaches some serious speeds 2 Flying fast Much more oxygen water has 5 mLL and air can have 210 mL O2L total air Oxygen delivery to tissue is better in air environments 0 Disadvantages Density air is less dense water is 1000x more dense must design robust skeletons Temperature thermal capacity is MUCH higher 2 Means very rapid changes in temperature air 2 Extreme cold 2 Unpredictable to boot Result Fast air breathing tetrapods o Pronghorn atelope o Arguably the fastest animal on land 0 Speeds of 50 mph o Migrators Physiological stresses 0 Waxy cuticle o Osmotic adaptations 0 Water conserving kidneys o Nocturnal lifesytles Respiration in air 0 Lungs o Drives water loss 0 Evolution of tracheal systems in insects Temperature variation 0 Varies with biome Tropical locations tend to be more stable Can be extremely cold Cold adaptation Migration to and form breeding grounds o Hibernation and estivation Variation in response to temperature 0 As body temperature increases relative performance also increases until it hits a certain temperature and then performance quickly declines OOO Lecture 20 Ecophys of Respiration in Air 31014 921 AM Respiratory Adaptations and Ecophysiology of Air Breathing Animals Some reminders o Essentials of gas exchange Exchange of respiratory gases O2 and CO2 All diffusion based not active transport Thus respiratory systems are comprised of 2 Gas exchange surfaces 2 Mechanismprocess to perfuse of ventilate those surfaces Summary of doing gas exchange in air vs water o Advantages better respiratory medium than water 392 why More oxygen in air Oxygen diffuses faster in air than water Air is lighter and requires less work to move the respiratory medium over the gas exchange surfaces o Disadvantages Water loss becomes an issue Faced with this new environmental problem in terrestrial habitats what can animals adjust o For example environmental osmotic extremes are found in deserts Double jeopardy extreme heat plus no water Physiological adaptations Behavioral adjustments Faces extreme water loss in desert and somehow survives in the total absence of freshwater how How animals interface with gas diffusion Gas exchange occurs across respiratory epithelium Alveolus line the entire epithelium of the lungs which facilitate gas exchange diffusion o Really small distance between alveoli and blood vessels for gases to travel 0 Have venous flow moving in the correct direction around the alveoli Lungs are pressurized Some basics Fick s Law of diffusion o Describes rate of diffusion from P1 to P2 two compartments and Q describes this 0 Q DA P1 P2L Q rate of gas exchange between P1 and P2 D diffusion coefficient cm2s 2 All things diffuse fast in air gas molecules like oxygen diffuse 10000 times faster 392 Organisms can maximize D by breathing in air instead of water 2 BUT animals cant change this value themselves A cross sectional area across which gas is moving 2 Adaptations which animals can adjust 2 If they increase A then they can increase Q In the mammalian example if they increase the alveoli this allows them to have a greater area for gas exchange P1 and P2 are partial pressures of gas at two locations L length of path between P1 and P2 0 P1 P2L partial pressure gradient alter P1P2 by driving the gradient and making it steeper maximize difference driving diffusion reduce L to increase Q Summary 0 Maximizing respiratory gas exchange Increase surface area A Maximize the partial pressure different that is driving the diffusion P1P2 Minimize the path length for diffusion L Reduce all diffusion that is done in water as opposed to air D but not likely because diffusion occurs across moist surfaces Tracheal gas exchange in insects Insects have long tubes through their body through which they breathe with a spiracle at the end that opens or closes it Open and closing and of spiracles creates discontinuous gas exchange cycles DGC O O Hypothesis DGC is operated to reduce water loss during respiration Minimize water loss RWL Ongoing debate and hypothesis many hypotheses o The hygric hypothesis DGCs reduce respiratory water loss 0 Chthonic hypothesis DGCs facilitate gas exchange during environmental hypoxia hypercapnia or both Not water content of the insect that regulates mechanism but the oxygen content of the environment Oxidative damage hypothesis DGCs minimize oxidative tissue damage Regulatory component is not water Instead needs to regulate radical oxygen and things when spiracles are closed Meta analysis of 40 species supported hygric hypothesis but people didn39t support this study Study on water striders 0 Results compatible with the hypothesis that respiratory patterns of insects are determined by the relationship between oxygen supply and oxygen demand not humidity Data from this study Tested time that spiracles are closed at different temperatures and also dry and wet climates 2 Not much difference between humid and dry trials in spiracles opening and closing at normal temperatures 2 BUT in different temperatures there were differences in spiracle closing Believe that these results are compatible more with the demand for oxygen in the environment increase temp increase metabolic rate increase need for 02 0 Conclusion all 3 hypothesis could be true But mostly suggests oxygen hypothesis Lecture 21 Respiration II Altitude 31014 921 AM
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