Final Exam Study Guide
Final Exam Study Guide Biology 152
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This 41 page Study Guide was uploaded by BettyAnn Mead on Tuesday May 5, 2015. The Study Guide belongs to Biology 152 at University of Massachusetts taught by Peteh in Winter2015. Since its upload, it has received 147 views.
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Date Created: 05/05/15
Animal Form and Function Adaptations Tradeoffs AnatomyPhysiology Homeostasis Anatomy and Physiology AnatomyThe study of an animal s physical structure Physiology The study of how the physical structures in an organism funcUon Antarctic Ice Fish Why do Ice Fish lack red blood cells Losseroded of the genes that make hemoglobin Evolved an adaptation to deal with very cold water No natural selection to weed out deleterious mutation to he globin gene Other ways to get oxygen to their tissues ce Fish Have Evolved To Lose ability to 0 Make hemoglobin 0 Make red blood cells Develop the ability to 0 Use higher levels of dissolved oxygen found in cold water 0 Absorption Larger gills and scale less skin with unusually large capillaries 0 Delivery Larger heart and greater blood volume Adaptation Adaptation A trait that allows an individual to survive in certain environments relative to individuals without that trait Adaptations evolve by genetic change that occurs over generations in response to natural selection in a population What is Evolution 0 A change in frequency of adaptations traits in a population over time 0 And therefore a change in the gene frequencies that code for those adaptations in a population over time Adaptation can be behavioral 0 Example Group hunting and herding in wildebeest Adaptations can be physiological Adaptation can be molecular Acclimatization Acclimatization A phenotvoic change that occurs in an individual in response to a shortterm change in environmental conditions Acclimate by increasing hemoglobin concentration 0 The ability to do this is an adaptation TradeOffs A constraint on an adaptation is a tradeoff which may involve expenditures if time and energy TradeOff An inescapable compromise between traits Hypothesis Testing 0 Generate AlternativeComplementary Hypothesis 0 State Null Hypothesis 0 Generate predictions of all hypothesis and null hypothesis 0 Design experimentobservations to test predictions 0 Compare results to predictions 0 State conclusion Adaptive Structures 0 A structure found in an animal is adaptive if it helps the individual survive and produce offspring The structures size shape or composition often correlates closely with its function Homeostasis Homeostasis The maintenance of relatively constant chemical and physical conditions in an animal s cells tissues and organs Conformational Homeostasis Conformation to the external environment Regulatory Homeostasis A physiological mechanism that adjusts the internal state within tolerable limits regardless of the external conditions Regulation and Feedback Homeostasis requires a regulatory system that has a set point or normal value 0 Regulatory Systems 0 Sensor 0 Integrator o Effector Homeostasis Systems Sensor A structure that senses some aspect of the external or internal environment lntegrato A part of the nervous system that evaluates sensory information and decides if a response is necessary to achieve homeostasis Effector Any structure that helps to restore that desired internal condition Negative Feedback When the regulatory system makes a change in the opposite direction to a change in internal conditions Importance of Thermoregulation Too hot 0 Macromolecules lose conformation shape and cease to function This includes proteins tRNAs etc FORMFUNCTION 0 Excessive water loss and dehydration Too cold 0 Metabolic processes slowedenzyme reactions and energy production 0 Damage of structuresice crystal formation Effectors If TbodygtTset Dilate blood vessels of skin 0 Increase blood ow 0 Increase heat loss Stimulate sweat glands o Evaporative heat loss Stimulate breathing 0 Heat via panting If TbodyltTset Constrict blood vessels of skin o Decrease blood vessels 0 Decrease heat loss 0 Muscle shivering o Generates heat Stimulate cellular respiration 0 Generate metabolic heat Gaining and Losing Heat Endotherm Produces heat in it s own tissue Ectotherm Relies on heat gained from the environment Type of Temperature Homeostasis Homeotherms Keep their body temperature constant Heterotherms Experience changes in body temperature TradeOffs Ectothermy VS Endothermy Endotherms o Enzymes at optimal temperatures at all times Remain active in winter and at night Sustain very high levels if aerobic activities such as running or ying Endotherms 0 Must obtain large quantities of energyrich food Ectotherms Able to thrive with much lower intakes of food 0 Greater proportion of energy intake goes to reproduction Ectotherms Muscular activity and digestion slow down dramatically as body temperature drops 0 More vulnerable to predation in cold weather Adaptations for Temperature Regulation 0 Biochemical o Conformational stability in proteins and other macromolecules tRNA rRNA etc 0 Heat stress proteins 0 Amino acid substitution in proteins 0 Physiological 0 Brown fat metabolism 0 Shivering o Sweating Behavioral o Feather uf ng tail shading etc 0 Moving into microenvironments 0 Water seeking Levels of Organization Atomic and molecular level Membrane protein in nerve cells admits a ow of ions Cellular level Electric signal mediated by ion ows travels down length of neuron Tissue level Electric signals travel from cell to cell in nervous tissue Organ level Nervous tissue and connective tissue in brain aid in sight smell memory and thought System level Nervous system controls breathing digestion movement and other functions Organism level Systems work together to support life Emergent Properties of Biological Systems 0 Characteristics of the whole cannot even in theory be deduced from the most complete knowledge of the components 0 Complex systems must be studied at all levels because each has properties not shown at higher levels Tissue Types Self Study Guide There are four different types of tissue Connective o Nervous Muscle o Epithelial Connective Tissue Cells that are loosely arranged in a liquid jelly like or solid extracellular matrix 0 Loose connective tissue serves as a packing material between organs 0 Blood transports material throughout the body Cartilage and bone support the body Nervous Tissue Nerve cells or neurons make up nervous tissue 0 All neurons have connections to other cells and deliver signals in the form of electrical impulses Muscle Tissue 0 Muscle tissue functions in movement Muscle cells are packed with specialized proteins that move in response to phosphorylation Three types 0 Striated 0 Cardiac 0 Smooth Striated Muscle Most muscle tissue is striated muscle which consists of long cells called muscle bers Cardiac Muscle Cardiac muscle makes up the walls of your heart 0 Like skeletal muscle in structure but each cardiac muscle cells branched and makes direct contact with other cardiac muscles 0 Connections help transmit signals from one cardiac muscle call to another during a heartbeat Smooth Muscle Are tapered at each end and form a tissue that line the walls of the digestive tract and the walls of arteries 0 Different types of neurons control the contraction of smooth muscle calls and striated muscle cells Epithelial Tissue Cover the outside of the body and line the surface of organs 0 These tissues consist of layers of tightly packed cells Organs Organ A structure that serves a specialized function and consists f several tissues Systems A system consists of tissues and organs that work in conjunction to preform a function Integumentary System 0 Hair 0 Skin 0 Nails 0 Encloses internal body structures 0 Site of many sensory receptors Skeletal System Cartilage 0 Bones 0 Joints 0 Supports the body 0 Enables movement with muscular system Muscular System Skeletal muscles Tendons o Enables movement with skeletal system 0 Helps maintain body temperature Nervous System 0 Brain Spinal cord 0 Peripheral nerves o Detects and processes sensory information o Activates bodily responses Endocrine System Pituitary gland Thyroid gland Pancreas Adrenal gland TestesOvaries o Secretes hormones o Regulates bodily processes Cardiovascular System 0 Heart 0 Blood vessels 0 Delivers oxygen and nutrient to tissues 0 Equalizes temperature in the body Lymphatic System 0 Thymus Lymph nodes Spleen Lymphatic vessels 0 Returns uid to blood o Defends against pathogens Respiratory System Nasalpassage Trachea Lungs o Removes carbon dioxide from the body 0 Delivers oxygen to blood Digestive System Stomach 0 Liver Gall bladder 0 Large intestine Small intestine o Processes food for use by the body 0 Removes wastes from undigested food Urinary System Kidneys Urinary bladder 0 Controls water balance in the body 0 Removes wastes from blood and excretes them Male Reproductive System o Epididymis Testes o Produced sex hormones and gametes o Delivers gametes to female Female Reproductive System Mammary glands Ovaries Uterus o Produced sex hormones and gametes 0 Supports embryofetus until birth Produced milk for infant The Nervous System Sensory Receptor l l l Integration l l Effector Sensory lnput Motor Output Neuron or Nerve Cell The functional unit of the nervous system Neuronal Morphology Nerve impulses are conducted along a neuron Dendrite Cell Body Axon Hillock l Axon Dendrites o Projections from the cell body 0 Receive information from other neurons Cell Body 0 Contains nucleus and organelles Axon Nerve impulse propagates along single axon away from cell body Axon Hillock Where axon joins cell body 0 Transmission and integration of nerve signals Synaptic Terminal 0 Nerve ending that relays signals via neurotransmitters to next neuron Synapse Place where synaptic terminals of one neuron come into contact with another neuron Synapse Place where synaptic terminals of one neuron come into contact with another neuron Presynaptic Cell 0 Action potential in presynaptic cell 0 Depolarization of presynaptic membrane Voltagegated calcium channels open In ux of calcium ions Synaptic vesicles fuse with presynaptic membrane Neurotransmitter is released from vesicles by exocytosis Synaptic Cleft Neurotransmitter diffuses across synaptic cleft o Neurotransmitter removed from synaptic cleft Postsynaptic Cell 0 Neurotransmitter binds to receptors in membrane 0 Ion channels coupled to the receptor open Membrane potential changes 0 Change can be depolarizing excitatory 0 Change can be hyperpolarizing inhibitory 0 Electrical change in postsynaptic neuron as a result of binding of neurotransmitter to receptor is called 0 Excitatory Synapse Excitatory Postsynaptic PotentialEPSP Open gated channels that allows sodium to enter and potassium to exit 0 Inhibitory Synapse Inhibitory Postsynaptic Potential IPSP Open gated channels that allows chloride to enter and potassium to exit Temporal Summation Generated from a single neuron repeatedly Spatial Summation A sum of multiple neuron signals Sub Threshold DO NOT reach threshold NO ACTION POTENTIAL Types of Synapses Neuron to neuron Neuromuscular Neuron to gland General Characteristics of Neurotransmitters Most neurons release only one neurotransmitter but some may release two or more 0 More than 100 neurotransmitters are known Neurotransmitters may be synthesized in the axon terminal or in the cell body and then transported In either case the synthesizing enzymes are made in the cell body Blockers Drugs or poisons that block receptor Reuptake Blocker Blocks the neurotransmitter from connecting to receptors Evolution of Nervous System Vertebrate Neurons Voltagegated channels 0 Unidirectional transmission 0 Chemical synapses Evolutionary Sequence 0 Ion channels gt Voltagegated channels 0 Bidirectional gt Unidirectional Electrical junctions gt Chemical synapses The Brain 0 CNS Organization Highly organized into tightly integrated functional subun s Wrinkles increase surface area and connections Emergence of cephalization cephala head Vertebrates develop three brain regions 0 Hindbrain o Midbrain o Forebrain Thinking and decision making Forebrain became important in mammals Somatomic Voluntary Autonomic Nonvoluntary Sympathetic o Parasympathetic Transduction Transformation of one type of energy into electrical impulses in nervous system 0 Sensory receptor Transducers Types of Sensory Receptors Mechanoreceptors Pressure touch motion and sound 0 Pain Receptors Excess heat pressure chemicals released from in ammation Thermo Receptors Cold and hot interoreceptors for temperature to anterior hypothalamus Chemoreceptors Solute concentration as well to speci c molecules Photoreceptors Sensory receptors in the eyes that respond to photons of light energy lnteroception Sensory processes having to do with conditions outside the body Exteroreception Sensory processes having to do with conditions outside the body Gravity 0 Motion The Theory of Evolution What is evolution 0 A change in the frequency of traits and the underlying genes in a population of a species over generations Ultimate VS Proximate Questions 0 Proximate o How does it work 0 How did it develop 0 Ultimate 0 What was it s evolutionary history 0 What is it s current utility H5N1 Ecology Disease spread 0 Evolution How the virus will change Traits 0 Ability to enter human host 0 Ability to escape human immune system 0 Ability to make new variants Darwinian Medicine 0 Pain 0 Low blood iron levels during infection Nausea during pregnancy Infectious coevolution Disease causing genes good Design tradeoffs walking upright Historical constraints Uniformitarianism Geological processes function today same as they did in the past Darwin s Theory 0 Species related through common decent New species evolve through a process of natural selection Natural Selection 0 Variation Heritability variation coded in genes 0 Differential reproduction Darwin s Synthesis 0 Combined his observations with ideas he had encountered Patterns of species in Galapagos Population surplus not all individuals survive Ideas from Geology 0 Past processes same as today 0 Geological time 0 Animal breeding and fossils What is the evidence for evolution Critiques of Natural Selection 0 Some traits are too complex 0 Counterargument 1 Cumulative selection Cumulative Selection For a population to evolve complex traits Each step of the evolution of the traits must confer an advantage on those that have it o Counterargument 2 Imperfections in nature 0 Nature of the evidence 0 Counterargument 3 Fossil record Gaps Every time you nd a new fossil that lls a gap it created two new gaps Paleontologists keep digging and nding new fossils No surprise there is gaps since the creation of fossils is a rare event Fossil Genes Genes that have mutated into nonfunctioning sequences that are still identi able Genetic Code Four different letter base pairs of DNA Arranged into three letter words that spell out names of amino acids Words arranged into sentences genes that describe a string of amino acid that form a protein Proteins are building blocks and regulators Changing a letter in a word can describe a different protein Change can have no a positive or a negative effect What happens to mutations Proteins determine traits If a trait is adaptive a change making it nonadaptive will be selected against and it won t be passes on to the next generation If a mutation makes a trait that is adopted it will be selected for If a trait is no longer necessary then a mutation will be neutral and it ill be passed on o Counterargument 4 Homologous structures Homology A special type of similarity based on common evolutionary ancestry Immortal Genes Genes that are shared by all forms of life Evolved early in the evolution of life Necessary for basic functions Convergent Evolution 0 Some similarities are analogies not homologies Due to common environmental pressures not common inheritance Super cially similar features evolve independent and do NOT indicate evolutionary relatedness o Counterargument 1 Arti cial selection 0 Counterargument 2 Actual observations Evidence for Evolution 1 Different species are related homologies 2 Species change over time Fossils of extinct organisms Fossil quotseriesquot showing replacement of one type of organism with a similar but different one Vestigial traits Observations of Natural Selection Evolution Pattern and Process Pattern Descent with modi cation Process Natural selection 0 The mechanism of evolution Natural Selection Darwin s approach Observation and Inference Inference The process of deriving logical conclusions from premises known or assumed to be true Observations 1amp2 Over production 0 Reproductive rates are high 0 But population sizes are relatively constant 0 Inference More individual are born then survive 0 Conclusion Individuals compete to survive and reproduce Observation 3 Variability o The individuals in a population are not identical 0 Inference Some individuals have traits that help them survnve 0 Conclusion The subset of the population that survives long enough to reproduce is not a random sample Differential Reproduction Observation 4 Inheritance Some of the traits that vary among individuals can be passed to offspring UL o Inference Favorable traits will be more common in the next generation 0 Conclusions Individuals whose traits allow them to best survive are reproduce will leave the most offspring Those offspring will inherit the favorable traits Summary of Natural Selection 0 Competition Variation 0 Differential representation of favored phenotypes in succeeding generations 0 Over periods of time changes accumulate Darwinian Fitness The ability of an individual to survive and reproduce Measured in terms of relative reproductive success Adaptation lnheritable traits help an individual to survive and reproduce ie That increases the tness of an individual relative to other individuals Selection Pressure or Agent of Selection The neutral or anthropogenic force that affects an individual s survival and reproduction Examples include predators soil moisture plant toxins and parasites Evidence of Natural Selection 0 Arti cial selection experiments 0 Observations of rapid evolution 0 Experiments in the eld A Few Points About Natural Selection 0 Individuals are selected but populations evolve 0 Even small differences in tness can be signi cant 0 The best phenotype depends on the environment which can change 0 Selection does not cause variation it edits variation Evolution Pattern and Process Darwin s and Wallace s contribution Complied copious evidence to document the pattern Recognize and described the process mechanism Sexual Selection o A special case of natural selection 0 SURVIVAL IS NOT ENOUGH o Advantage in mating must be ABOVE AND BEYOND the cost to survive Darwin s Other Big Idea Elaborate males cryptic females Males appear to compete for females 0 Females appear to choose males 0 Enhanced ability to obtain mates Occurs when individuals in a population differ in ability to attract mates Sexual Selection Pattern and Process 0 Pattern Seems to act more strongly on males traits that respond to sexual selection are more elaborate in males Sexual dimorphism Process Consequence of differences between the sexes in parental investment The Connection Between Male Dominance and Reproductive Success 0 Result Sexual selection on males for qualities such as large size that enhance ghting ability BUT in many species subordinate males may secure mattings by alternate means Satellite Behavior 0 Some male toads wait silently near another male that is calling to attract females 0 Try to intercept and mate with the females that are moving toward the calling male 0 Both behaviors persist in population even though satellites have less reproductive success FrequencyDependent Selection The phenotype that yields the greatest tness depends on how common each alternative phenotype is 0 Many traits have evolved because they help males win the competition for access to females 0 But what about females 0 Theory predicts females should be choosy 0 Do females make bene cial adaptive choices 0 Easiest to tell when male provides female with direct material bene t Example Food or parental care Sexual Suicide The male inserts his sperm into the female and then enters her mouth In most animal species though males provide only sperm oWhen females get no direct material bene t are they still choosy o Females prefer males with particular traits even when males provide no direct bene t 0 Female s preference can select for the evolution of extravagant ornaments and behaviors Why Sex Key Concepts Parasite load Redqueen hypothesis Inbreeding and population bottlenecks Genetic Drift By chance some individuals may leave more offspring just by chance 0 In contrast evolution via natural selection selects individuals with higher tness not just by chance 0 Genetic drift is more common in smaller populations Costs of Sex 0 Time and energy devoted to mating Exposure to predation during courtship Sexually transmitted disease 0 Females Only 50 of genes passed to next generation 0 Population growth rate have lower upper bound Bene ts of Sex 0 Better ability to deal with harmful mutations Genetic diversity to deal with changing environment 0 Diseases 0 Food sources 0 Climate change Species 0 Variation in life s form not continuous Life come in discrete packages 0 These distinct entities are species 0 Objectively real not arti cial constructs 0 Evolution must produce not only changes over time within a lineage but must also create new lineages What mechanism creates and maintains new species What is a species 0 Not fully addressed until 1930 s 0 Thought of species as reproductive communities The Biological Species Concept 0 quotSpecies are groups of actually or potentially interbreeding natural populations which are reproductively isolated from other such groupsquot Species 0 Variation in life s form not continuous Life come in discrete packages 0 These distinct entities are species 0 Objectively real not arti cial constructs 0 Evolution must produce not only changes over time within a lineage but must also create new lineages What mechanism creates and maintains new species What is a species 0 Not fully addressed until 1930 s 0 Thought of species as reproductive communities The Biological Species Concept 0 quotSpecies are groups of actually or potentially interbreeding natural populations which are reproductively isolated from other such groupsquot Speciation How do species remain separate 0 What are the conditions under which a separation can evolve How do species remain separate 0 Reproductive isolating mechanisms prevent interbreeding o PrezygoticBefore Fertilization Behavioral Temporal Ecological Mechanical 0 Post zygoticAfter Fertilization Hybrid unviabilitysterility Lowered tness of hybrids What are the conditions necessary for speciation Genetic isolation 0 Gene ow restricted or blocked Evolutionary divergence 0 Genetic drift natural selection sexual selection and mutations How can the isolation step happen Allopatric A population is subdivided into two or more geographically separated parts 0 Colonization of newly formed islands o Rising sea level isolates former part of mainland as an island 0 Geological change Example Mountain building river course changing 0 Formation of island habitat Example After climate change 0 Continental drift plate tectonics Sympatric A population is genetically subdivided even though it is not geographically subdivided Ecological partition 0 Chromosomal mutation polyploidy Sensory drive Sensory drive Another mechanism that can result in female predispositions to male signal characteristics Sensory Drive 0 Live in different habitats where characteristics of light are different 0 Light intensity 0 Spectral qualities Retinas of different surfperch are quotturnedquot to the characteristics of light in a particular habitat o Retinal cones can either be optimized for detecting color contrast or light intensity cones 0 Only room enough for so many comes in eyes so it s a trade off which you can do best 0 Habitat and retinal differences are correlated 0 Species living in deep water environments have more light intensity cones 0 Species living in shallow water environments have more color contrast cones Mate choice Male markings depend on female sensory abilities o Males of species that live in deep environments have marking that are best detected by brightness cones Male s species that live in shallow environments have markings that are best detected by color contrast cones What is Ecology o Ernst Hackle 1866 From Greek term for home quotOikosquot quotThe total relations between an organism and is organic and inorganic environment Molles quotThe study of the relationships between organisms and the environmentquot Townsend Harper Begon 2000 quotThe scienti c study of the distribution and abundance of organisms and the interactions that determine distribution and abundance o HOULIHAN Today quotThe scienti c study of the patterns of distribution and abundance of organisms and the mechanisms that determine the patterns of distribution and abundance Ecology Patterns Distribution and abundance Mechanisms Interactions between organisms and their environments 0 Both nonliving abiotic and living biotic components of the environment 0 Focus Distinguished by the level of organization at which ecologists work Levels of Organization 0 Organism An individual animal 0 Population Groups of individuals of same species inhabiting an area 0 Community Groups of populations in an area Ecosystem Communities and nonliving components Biosphere The entire earth system Why study population ecology The environment of an organism consists of anything that might effect it s chance to survive and reproduce When we model the ecology of an organism we only include those components of the environment that matter What are the components of and organism s environment Abiotic Nonliving nutrients climate etc Biotic Living Population Dynamics The patterns of and mechanisms of population change Population Growth and Regulation Simple model of population growth 0 Change in population size Births Deaths IGNORING EMMIGRATION AND IMMIGRATION rgt0 population is growing rlt0 population is shrinking r0 population is stable Exponential Growth dNdtrN If r remains constant and gt0 the number of individuals added to the population each year grows continuously Curve has no upper limit Population size increases more rapidly when r is larger A population has a hypothetical maximum possible value of r The intrinsic rate of increase rmax Represents a population s growth rate under ideal conditions unlimited resources o In the real world populations do not maintain exponential growth O 0000 0 Population growth approaches a limit r declines Eventually a limit is reached r0 Population has reached it s maximum sustainable size carrying capacity Designated K Population s size increases inde nitely at a rate determined by the rate of increase Logistic Growth 0 Population size increases at an increasing rate and then at a diminishing rate until it reaches a limit called carrying capacity K dNdtrmaxNK NK What limits population growth 0 Density dependent factors 0 Predation Including parasitism 0 Availability of resources Example Food space etc o Accumulation of wastes 0 Behavior change 0 Density independent factors 0 Weather Example Annual freezes periodic droughts oods unpredictable storms etc 0 Sex ratio 0 Age structure 0 Community Ecology Characteristics of community as a whole Interactions among species Competition 0 Use or defense of a resource by one individual that reduces the availability of that resource to other individuals 0 Can be intraspeci c within a species or interspeci c between species 0 lntraspeci c competition is most intense members of same species consume the same resources Resource Any substance or factor that is used by an organism 0 And that can lead to increased population growth as its availability increases Example Food water space hiding places etc 0 Population size is limited by quantity and quality of resources especially the limiting resources Limiting Resources Species interactions in communities 0 Each species interacts with many other species 0 Communities include complex webs of interactions among many species 0 Connections often revealed by unexpected outcomes when communities are disrupted Community dynamics revealed by disruptions Apex predator extirpation l Trophic cascade Deforestation l Vertebrate disease increase Invasive species l Lose of native biodiversity Trophic Levels and Ecological Pyramids Energy Flow 0 Primary producers capture energy 0 Usually photosynthetic organisms Consumers Primary consumer eat producers Secondary consumer eat primary consumer Tertiary consumer eat secondary consumer And so on Theory of Island Biogeography Predicts dynamic equilibrium of species on any particular island based on 0 Size of island 0 Distance from mainland source of species 0 Number of species on island determined by 0 Immigration Rate Species added 0 Extinction Rate Species subtracted Habitat Fragmentation Created habitat islands that are smaller and more isolated than the larger landscape they came from Minimum Critical Size of Ecosystems Project 0 As forests are cleared in Brazil fragments of various sizes are preserved 1 10 100 1000 hectares Monitor diversity of selected groups over following years Minimum Critical Size of Ecosystems Project RESULT ONE 0 In small fragments some bird and mammal species disappear Less dung and carrion Scarab beetles become scarcer Mites that infest beetles become scarcer 0 Fewer mites means more ies More ies mean pathogens spread more rapidly Keystone Species A species whose importance to community is great relative to its abundance o Often identi ed when removed Exotic and Invasive Species Communities can be disrupted by exotic species 0 Species introduced by humans to communities in which they were not previously found 0 Introduction can be intentional or unintentional 0 Have affected virtually all communities but especially problematic in disrupted habitats o Exotics often invasive 0 Native species often negatively affected Costs of lnvasive More than 4500 foreign species have gained a permanent foothold or taken root in US during the past century Invasive species contribute to the decline of 46 of the imperiled or endangered species in the US Invasive species are estimated to cost a total of 137 billion annually in losses to agriculture forestry sheries and the maintenance of open waterways in the US Characteristics of lnvasive Rapid population growth Displace or kill native species 0 No natural population regulation 0 No predators o No pathogens 0 High dispersal rate 0 The resources that is scarce relative to the demand for them Ecosystem Biogeochemical Cycles Nutrients cycle through a system Biogeochemical NUTRIENT ows are generated by ORGANISMS and GEOLOGICAL processes Global Climate Change 0 Three patterns 0 Increase in airborne carbon as C02 0 Increase in global temperature 0 Ocean acidi cation Mechanism What is the link The Carbon Cycle 0 Important terrestrial carbon sinks include o Forests 0 Peat lands 0 Permafrost Geological Sinks Over long periods of time 0 Biological carbon is converted to coal oil and gas 0 Marine organisms die and become ocean sediments and eventually turn into rocks limestone etc Carbon Cycle 0 Atmosphere contains large sink of carbon as C02 0 Plants absorb C02 and via photosynthesis convert it to carbohydrates 0 Animals metabolize carbohydrates and release carbon as C02 0 Sea surface absorbs and releases C02 in atmospheric sink 0 Marine organisms use carbon to build their bodied In addition carbon cycle through oceans in several forms 0 Carbon is sequestered as fossil fuels and in ocean sediments Humans release stored carbon by burning fossil fuels and cutting down forests Carbon Cycle Key Points 0 Carbon cycle through several compartments 0 Atmosphere 0 Oceans 0 Biological 0 Geological Some carbon is sequestered into sinks Humans are releasing carbon from geological sink faster then it is returned and can be absorbed by oceans How have atmospheric C02 concentration change over time 0 Since 1880 280 ppm to 390 ppm 0 During ice ages 100 ppm change took 10000 s of years How do we know CO2 is from human activity Volcanoes and C02 0 When volcanoes release magma this also releases C02 and other gases 502 etc o The best estimate is that volcanoes produce about 200 million tons of C02 annually 0 Volcanoes produce less than 1 of what humans do 1 Correlation between C02 increases and increase in use of fossil fuels 2 Isotope signature of atmospheric C02 lsotopes Some element different number of neutrons Isotopic signature of C02 from fossil fuels 0 Common isotopes are 12C and 13C 0 Plants have a preference for the lighter isotopes 12C and 13C thus they have lower 13C12C ratio 0 Since fossil fuels all have roughly the same 13C12C ratio about 2 lower than that of the atmosphere 0 As C02 from these materials is released into and mixes with the atmosphere the average 13C12C ratio of the atmosphere decreases Why is the amount of CO2 increasing 0 Carbon Balance Carbon released into atmosphere Carbon absorbed by land ocean etc Carbon left in atmosphere Biological Effects of Climate Change 0 Increased C02 0 Changes in climate Changes in Ocean Chemistry Ocean Acidi cation lncrease C02 in atmosphere it will increase in ocean water 0 C02 in water changes to an acid which decreases the pH of the water 0 C02 H20 l CARBONIC ACID 0 As pH decreases this impacts organisms that build parts of their bodies with calcium carbonate Since 1850 s 0 30 increase in ocean acidity 100x faster change then last 20 million years Does it have an affect Lab experiments show impacts on calcareous animal growth immune response and reproduction Lab experiments show shell and coral deterioration at lowered pH 0 Areas of ocean that naturally have lower pH have fewer organisms that have structures made of calcium carbonate 0 Parts of the ocean that composition of plankton species Reefs where pH has declined have exhibited coral thinning Climate Change Biology Increasing temperatures can make an area either less or more suitable for a given species Responses to Physiological Stress Stay in place 0 Global or local extinction o Acclimation o Adaptation Move 0 Dispersal Thomas et al Nature Jan 2004 Estimate species climate envelope will not evolve signi cantly in 50 years Model with and without species based dispersal Model three climate scenarios Range of extinction values from 18 to 35 Other studies predict up to 75 biodiversity loss Which species are most likely to adapt Those with short generation times 2 years or less Dispersal Dispersal rate Presence of dispersal agent Availability of suitable habitat Different species move at different rate This can disrupt ecological interactions and have a ripple effect through a community Latitudinal Shifts o Majority of North American birds have shifted ranges to the north in last 30 years 0 235 kilometersyear o Majority of British birds have shifted ranges to north 0 Wide geographic distribution of patterns implicates climate change Climate Change Effects 0 Habitat loss 0 Life Cycle Timing Cycles of activity and dormancy Reproduction Timing Solution to Climate Change Conservation Impacts o Mitigation o Decrease atmospheric inputs of C02 Adaptation 0 Conventional conservation approaches 0 Migration corridors o Assisted migration What is the risk of decline or extinction due to AGW 0 Low 0 Business as usual 0 Moderate 0 Improve connections to higher latitude habitats conservation corridors o Enhance gene pool with quotwarmquot genes 0 Reduce oca stressors 0 High High Risk Is it feasible to translocate No 0 Create habitat at higher latitudes 0 Can t create habitat store genes 0 Yes 0 Will they move on their own Yes then waits for them and help when they get there No determines if bene ts outweigh costs of translocation
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