BSC 116- FINAL EXAM STUDY GUIDE
BSC 116- FINAL EXAM STUDY GUIDE BSC 116
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This 38 page Study Guide was uploaded by Alexia Acebo on Monday December 7, 2015. The Study Guide belongs to BSC 116 at University of Alabama - Tuscaloosa taught by Jennifer G. Howeth in Summer 2015. Since its upload, it has received 405 views. For similar materials see Principles Biology II in Biology at University of Alabama - Tuscaloosa.
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Date Created: 12/07/15
**BSC 116 Final Exam STUDY GUIDE** Lecture 32-43 Lecture 32: Neurons Synopsis: neurons convey information from cell to cell chemical and electrical potential moves across the membrane o action potential action potential depends on depolarization of the neuron connections between cells (synapses) are usually chemical and involve neurotransmitters. **Animals (1)receive information (2)process (3) respond sensory input (received info) goes into the central nervous system, response is transmitted by the peripheral nervous system DEFINITION: neurons= specialized cells that conduct and store info in the nervous system Setup Cell body: houses most of cytoplasm, nucleus etc. Dendrites: branched extensions at receiving end Axon: extends from neuron to the cell it acts on o Axon hillock: where the axon joins cell body, signal gen. Function Becomes electrically excited conduction down axon Synapse=connection b/t neurons o Excitement (chemical) o Synaptic terminal in the presynaptic cell releases neurotransmitters. o Postsynaptic cell may or may not become electrically excited by the neurotransmitters Neuron= on/off switch Inside negatively/positively chargednot excited/excited Charge determined by movement of ions DEFINITIONS: Sensory neurons=transmit info from sensors that detect external stimuli or internal conditions Interneurons= from the local circuits connecting neurons in the brain Motor Neurons= transmit signals to muscle cells Glial Cells= nourish, insulate and regulate neurons -Neuron at Rest- DEFINITIONS: membrane potential=voltage difference across cell membrane as a result of unequal distribution resting potential=membrane potential of a neuron that is not excited Resting cell maintains K+-Na- gradient o ATP powered sodium potassium pump o Ion channels let ions move down their gradients o Net movement of charge is what creates voltage potential ***when a neuron is excited, the membrane potential goes from negative to positive DEFINITION: gated ion channels =respond to some stimulus by opening/ closing voltage gated ion channels= respond to change in membrane potential Hyperpolarization= membrane potential more negative Depolarization (less negative) of membrane potential activates voltage gated Na+ channels o Positive feedback: leads to further depolarization and more Na+ channels opening o Action potential: massive, rapid depolarization **Action potentials are propagated along axons During falling phase and undershoot, Na+ channels activated o Refractory period: time between action potentials Signal propagates because action potential in one area of axon depolarizes neighboring region Activation of K+ and inactivation of Na+ channels during refractory period Speed of propagation increases with axon diameter and “insulation” by glial cells **Vertebrates and neurons are insulated by glial cells 2 kinds of glial cells provide a myelin sheath around axons: electrical insulation o wrap axons in multiple layers of cell membrane o no leakage to dampen effect with distance o oligodendrocytes in CNS o Schwann cells in PNS Insulation allows depolarization to propagate farther/faster Voltage gated Na+ channels limited to gaps in myelin sheath: nodes of Ranvier o Depolarization jumps from node to node **Info passes in chemical form from 1 neuron to another In vertebrates, chemical synapses more common, NOT electrical synapses DEFINITIONS: Neurotransmitter=pre-synaptic chemical released by neuron Presynaptic axon terminal= neurotransmitter packaged into synaptic vesicles Postsynaptic membrane has ligand-gated ion channels that bind neurotransmitter. o Binding change in potential o Excitatory postsynaptic potentials: depolarize membrane slightly o Inhibitory postsynaptic potentials: hyperpolarize membrane slightly **The Number and type of synapses determines the response postsynaptic potentials graded rather than all or nothing Don’t exceed threshold then fade Multiple potentials can build up o Temporal summation- series of potentials from same synapse o Spatial summation- potentials from different synapse on cell Inhibitory potentials can cancel out excitatory potentials Lecture 33: Nervous Systems Synopsis: -neurons convey information from cell to cell -neurons are arranged into networks -nervous systems are large networks of neurons **different taxa= different nervous systems** Cnidarians: diffuse nerve net More complex animals: nerves of multiple neurons o Central nervous system (CNS) brain+ nerve cord(s) running body length Protostomes have ventral nerve cord Deuterostomes have a dorsal nerve cord o Peripheral nervous system: ganglia and nerves outside CNS !!Vertebrate CNS= large brain and spinal cord!! DEFINITION Brain: is where all stimulus and voluntary behavior is processed Spinal cord: carries impulses to and from brain -mediates reflexes: involuntary movement both made of grey matter ( NON-MYELIN) and white matter (MYELIN) **both derives from hollow dorsal nerve cord Central canal of spinal Ventricles of the brain Both filled with cerebrospinal fluid Role of glia in the CNS: nourish, support and regulate the functioning of neurons in the brain and spinal cord DEFINITIONS: Radial glia= embryonic glia that form tracks along which newly formed neurons migrate from the neural tube, the structure that gives rise to the CNS Astrocytes= facilitate info transfer at synapses and sometimes release neurotransmitters; initiates formation of the blood- brain barrier during embryonic development Radial glia + astrocytes= can act as stem cells, generating new neurons in glia Oligodendrocytes= myelinate axons in the CNS Schwann cells= myelinate axons in the PNS Microglia= immune cells that protect against pathogens Ependymal cells= line ventricles and promote circulation of cerebrospinal fluid **The PNS carries info to and from CNS*** DEFINITIONS: Cranial nerves= connect brain with head Spinal nerves= connect spinal cord to rest of body Afferent neurons= bring info to the CNS (sensory) Efferent neurons= carry info from CNS -motor system: skeletal muscles; voluntary (& reflexes) respond to external stimuli -autonomic nervous system: smooth and cardiac muscle, glands etc. ; involuntary sympathetic division: arousal, “fight or flight” parasympathetic division: calming “rest and digest” enteric division: digestion **Brain begins as 3 bulges of neural tube, develops into Hindbrain & midbrain o Brainstem= midbrain+ pons+ medulla Homeostasis, coordination, info sharing Attention, alertness, motivation o Cerebellum: coordinates movement, hand- eye coordination Forebrain o Diencephalon= thalamus+ hypothalamus+ epithalamus Homeostasis, coord. Sensory info, circadian rythms o Cerebrum: center for learning, emotion, memory, perception 80% of brain outer cortex of grey matter connected by corpus callosum **Sleep and emotions are locally regulated in the brain controlled in part by reticular formation:diffuse network of neurons in the core of the brain stem; filters incoming info to determine what gets to cerebellum more info to cerebellum= more alert/awake Pons and medulla: regulate sleep Biological clock: regulates sleep cycles coord. By group of neurons in hypothalamus and melatonin from the pineal gland Limbic system: borders the brainstem, responsible for emotions includes amygdala, hippocampus and thalamus **Cerebral Cortex controls things we make decisions about 4 LOBES 1.Frontal 2.Parietal 3.Occipital 4.Temporal Sensory info received from thalamus o Received in primary sensory areasassociation areas to make sensefrontal association area to be acted on Different functions localized in different areas o Broca’s area: controls muscles in the face, active during speech generation o Wernicke’s area: active when speech is heard, facilitates comprehension Lateralization: 2 hemispheres not identical in function 3 Process determine structure of the NS during embryonic development 1.Gene expression, signal transduction, etc. establish structures 2.Huge neuron die-off a.Not in right place= die off b.50% lost 3.Synapse reconfiguration a.Each neuron initially forms more synapses than needed b.Gets rid of extra Learning and memory based on neural plasticity after embryonic development o synaptic connections weaken or strengthen o memories form by rearranging connections in hippocampus short term= store stimuli for short period to see if important long term= rearrangements in cerebral cortex Long term potentiation-ex. Of how synaptic connections changed o Frequent excitation of a synapse can make the postsynaptic neuron more sensitive to the presynaptic neuron Neural Diseases •schizophrenia •depression •drug addiction •Alzheimer’s disease •Parkinson’s disease Lecture 34: Sensory and Motor Mechanisms Synopsis: Different types of receptors code external stimuli as action potentials EX: chemoreceptors, mechanoreceptors, photoreceptors 4 Stages of getting a stimulus to the brain: 1.Reception: sensory cell detects stimulus 2.Transduction: conversion of stimulus to receptor potential 3.Transmission: if receptor potential initiates action potential a.Receptor cell- axon or neurotransmitter b.Strength of stimulus modulates frequency of action potential c. Integration= processing might begin even before transmission 4.Perception: CNS processing of input from sensory neurons **Transduction can be modified in 2 ways: 1.Amplification: strengthening the stimulus; adding energy 2.Adaptation: become unresponsive to constant stimulation Different Types of Sensory Receptors Chemoreceptors: bind molecules, initiates change in membrane potential Mechanoreceptors: deformed or moved to sense pressure, stretch, motion etc. Electromagnetic receptors: detect light, electricity, magnetism etc. Thermoreceptors: detect heat and cold Nocireceptors: detect pain, like extreme pressure, chemicals etc. **Taste and smell both rely on chemoreceptors** Gustation= taste; detection of tastants in solution o In animals: taste buds o In insects: bottom of feet and mouth parts Olfaction= smell; detection of odorants in air o Mammals: receptors in upper nasal cavity **Hearing and balance both based on mechanoreceptors** Hearing= pressure waves in the air deform receptor cells, leads to membrane potential perception of vibrations Starts with conversion of waves in air to fluid o Outer ear: tympanic membrane (eardrum) vibes o Middle ear: 3 tiny bones transmit o Inner ear: cochlea receives vibrations Waves flow down vestibular canal, cause vibrations that stimulate hair cells o Hair cells releasing neurotransmitter all the time o In one direction- depolarize, in other direction- hyperpolarize Second stimulus has both volume and pitch o Volume- magnitude o Pitch- frequency Fish- no need to convert air pressure o No outer ear- vibes pass from water through body Lateral line system= mechanoreceptors for detecting low- frequency vibrations perceive the direction and velocity of water, predators, prey Insects- have “hairs” that vibrate o Some have tympanic membrane **Balance requires sensing orientation relative to gravity and angular momentum** Many animals have statocysts to sense gravity o Chamber surrounded by ciliated cells o Statoliths move around as body moves In mammals. Balance assoc. with ears o Inner ear has utricle (horizontal) and saccule (vertical) o Chambers lined with hair cells and little stones (otoliths) o Tilt head stones move o Semicircular canals detect angular momentum **Light Detection** Photoreceptors: cells that detect light Light detecting organs o Ocelli: simple cup of photoreceptors Creates shadow to determine light direction Single- lens eyes: functions like camera o 1 opening with a lens to focus light on a field of photoreceptors Compound Eyes: composed of many detectors, ommatidia o Insects o Each facet has own lens Lecture 35: Sensory and Motor Mechanisms II Synopsis: Effector neurons work on muscles Sliding filament model of muscle function Contraction is the sum of many twitches Muscle contraction action **Complicated integration of signals leads to a specific response response can act on the endocrine system, muscles **Skeletal muscle contracts to move skeletal elements Characteristic organization: linear fibers within fibers o Muscle= bundle of fibers running parallel to bone o Fiber= single cell (multiple nuclei) with bundle of myofibrils Sarcomere: basic contractile unit of myofibril o Ends of actin fibers line up at ends: z lines o Middle of myosin fibers: m line o “striated muscles”: array of adjacent sarcomeres muscles contract by actin and myosin sliding past each other: sliding-filament model myosin molecule: long tail and round head o tails of myosin stick together in thick fiber o head is where all the action is 1.Head binds ATP (low-energy configuration) 2.Head hyrolyzes ATP to ADP , uses energy to change shape: head moves forward 3.Head binds to adjacent thin (actin) filament 4.Head releases ADP but holds on to actin a.Changes shape to pull thick filament against thin 5.Binding new ATP causes head to release cycle restarts ***Ca 2+ & regulatory proteins control contraction of muscle fibers*** 2 sets of regulatory proteins are bound to the thin (actin) filaments o tropomyosin: coils around actin o troponin complex: arranged along tropomyosin o proteins block myosin binding-sites: inhibits actin-myosin interaction Ca2+ in cytoplasm binds troponin complex: results in exposure of myosin binding sites !!An Action potential myofibril contraction!! 1.With action potential, motor neuron releases acetylcholine (neurotransmitter), binds to receptors on muscle 2.Triggers action potential, transverse tubules (ext. os plasma membrane) carry AP deep into muscle cell 3.AP causes sarcoplasmic reticulum to release Ca 2+ 4.Troponin complex and tropomyosin move out of the way 5.Sarcomere contracts 6.When motor neuron stops firing, Ca 2+ pumped back to SR 7.Troponin complex and tropomyosin move back in the way, fiber relaxes 8.Like action potential, muscle fiber contraction is “ all- or –nothing”, twitch **Whole muscle contraction is the sum of many twitches!!! Graded Each fiber controlled by 1 motor neuron Each motor neuron controls many fibers o Motor unit= all fibers controlled by one neuron All contract together Strength of contraction depends on # of neurons recruited and the size of the motor units that they control Rapid AP’s rapid twitches o Tension may not be lost bt them= tetanus “twitches” smoothed out by tendons **Some sort of skeleton is necessary to turn contraction action*** - muscle works in antagonistic pairs - many animals like mineralized or chitin skeletons : rely on hydrostatic skeletons Lecture 36: Animal Behavior Synopsis: sensory activity drives animal behavior environment and genetics influence behavior natural selection shapes behavior o optimal foraging o mate choice and parental care o sexual selection problem of altruism individual behavior: an action carried out by muscles under control of the nervous system in response to a stimulus **For many behaviors, a particular stimulus leads to a particular response** DEFINITIONS: Fixed action patterns: sequence of unlearned acts linked to a simple stimulus Signal: stimulus transmitted from one animal to another can be visual, chemical, auditory, tactile pheremone: a chemical cue often associated with a threat or reproduction Communication: the transmission and reception of signals between animals **the environment of an organism can influence its behavior** innate behavior: traits that are fixed by genotype individuals with the same genotype can have different behavioral phenotypes DEFINITIONS Learning: modifying behavior based on experience Imprinting: formation at a specific stage in life of a long-lasting behavioral response to an individual or object , includes a sensitive, critical period **behavior is the result of complex interactions of environment and genotype DEFINITIONS Cross fostering studies: offspring of one species raised by another Twin studies: look at identical twins placed with different foster families **ALL types of animals are capable of learned behavior** associative learning- associate one stimulus with another o classical conditioning: arbitrary stimulus leads to a certain response o operant conditioning: trial- and- error learning spatial learning- maintaining an internal map cognition- reasoning, awareness problem-solving- devising solutions to proceed past obstacles o social learning: many animals can learn by observing conspecifics **The ultimate causes of many behavioral traits are evolutionary*** 3 examples -optimal foraging -mate choice and parental care -sexual selection foraging= searching for food and eating o optimal maximize bemefit, minimize cost mating system= length and number of relationships between males and females o different species-----different mating systems/behaviors monogamy: long-term pair-bonding polygamy: multiple mated polygyny: one male, multiple females polyandry: one female, multiple males promiscuous: no pair bonding Sexual selection= a type of natural selection; result of differential mating success when there is competition for mates o Leads to sexual dimorphism in phenotypic traits: appearance and behavior Males usually compete to attract females Males physically compete for females **Altruism presents a problem for the evolutionary theory!! Altruism: doing something that lowers your own fitness but increases the fitness of others Inclusive fitness: fitness (REPRESENTATION OF YOUR GENES IN THE NEXT GENERATION) depends on your reproduction and that of your close relatives o William Hamilton’s Rule: rB>C Weigh the cost/benefit of an altruistic act Cost- the number of offspring that the act might cost the altruist Benefit- # of offspring that an action will gain the recipient R- coefficient of relatedness: avg. # of genes shared by the 2 As long as rB>C, benefit outweighs cost Lecture 37: Into to Ecology Synopsis: dist. of species- globally/locally, global dist. of biomes **Ecology study of how organisms interact with each other and their environments Organism interaction Individual Populations: groups of individuals of same species Communities: groups of populations Ecosystems: groups of communities Landscapes: groups of ecosystems Global: the earth: biosphere Ecology and Evolutionary Bio Evolutionary time: populations change to adapt to their environments Ecological time: response of organisms, populations, etc. to their environments Ecology and environmentalism Not the same thing- science v. advocacy **No species occurs everywhere Factors that determine distribution o Dispersal o Behavior Biotic: other living things Abiotic: physical factors Dispersal= movement of individuals to new areas **organisms may choose to avoid a livable habitat- psychological habitat selection **species distributions are often limited by other species biotic factors Species absent b/c other is missing Species absent b/c other is present **species distributions are limited by their physiological tolerances. abiotic factors Temp: too hot/cold Water: too wet/dry Sunlight: esp. for photosynthetic organisms Geology: the inorganic parts of the habitat o Earth is NOT homogenous for abiotic factors o Summarized as climate **Shape, tilt, etc. of earth results in broad climatic patterns Surface curved: areas away from equator get less intense sunlight Pattern of heating/ evaporation: variation in precipitation Axis rotation tilted 23.5 deg.: seasonal variation in sunlight Rotation of the earth: circulation of air/ water currents Local variations in climate Proximity to water o Air changes temp faster than water Mountains o Shadow to sunlight o Altitude and temp o Rain shadow Tilt of the earth results in predictable seasonality Long-term, global variation in climate Periods differ Until 15-20k y.a., northern latitudes covered by glaciers Species move north as climate warms Biomes: major habitat types, determined by biotic & abiotic factors -latitudinal variation in temp., moisture, etc. leads to latudinal variation in animals/ plants Ecotones: areas of transition between biomes **Disturbance community variation, patchiness !!Aquatic biomes are characterized by salinity and depth!! 75% of earth’s surface o freshwater <0.1% o marine 3% o pelagic (open) v. benthic (bottom) most photosynthesis at surface o photic v. aphotic Lecture 38: Population Ecology Synopsis: variation in life histories exponential growth logistic growth density dependence v. independence metapopulations **Populations change over time Population: conspecific individuals occurring in a particular area Populations are dynamic o Gain individuals from birth o Gain individuals from immigration o Lose individuals from death o Lose individuals from emigration 3 characteristics to describe populations: o density= number of individuals per unit area ( or volume) boundaries difficult to define various methods estimate size/density mark recapture o dispersion: pattern of spacing o clumped: aggregated in patches o uniform: evenly spaced o random: independent of other individuals o demographics= age and sex structure of the population Life table- age specific summaries of survival in population single cohort construction from birth to death **Survivorship curve- graphical explanation of life table number alive plotted vs. each age species have characteristic survivorship curves depending on life history reproductive table= fertility schedule Cost of reptoduction= energy spent on offspring not spent on parent Iteroparity repeated reproduction; multiple periods Semelparity big bang reproduction: all reproduction concentrated in a single effort Trade offs: can’t maximize all reproductive patterns at the same time !!As long as there are more births than deaths POPULATION WILL GROW!!! population growth often regulated by feedback DEFINITIONS Carrying capacity: number of individuals that a habitat can sistain -limiting factors=energy, shelter, nutrients, territory logistic population growth model: incorporates carrying capacity K selection- for traits helpful at high densities R selection- for traits helpful at low densities ***Density dependence is ecological feedback*** When birth/death rates change with population size they are density dependent Equilibrium birth=death Causes of density dependent regulation o Competition o Disease o Predation o Accumulation of wastes o Intrinsic factors Versus density-independent **Population size is dynamic** **Populations vary in space as well as time** Populations connected by dispersal in a metapopulation o Sources: positive population growth , lots of emigration sinks o Sinks: negative population growth, lots of immigration from sources required to maintain population Habitat fragmentationmetapopulation Lecture 39: Community Ecology Synopsis: Interspecific Interactions and regulation of community structure Community: composed of 2+ species in space and time Ways that species interact in community: 1.Competition: -/- species compete for resources needed for growth, reproduction etc. 2.Predation: +/- one animal eats another a.Prey adapted to hide i. Cryptic coloration=camouflage ii. Aposematic coloration=brightly colored iii. Batesian mimicry= harmless resemblance iv. Mullerian mimicry= 2 venemous 3.Herbivory: special case of predation, animal eats plant/alga **Competition results from species overlapping niches** Niche: sum of the biotic and abiotic needs of a species, its place/role in a habitat o Wide niche overlaps = competitive exclusion o Narrow niche overlaps= resource partitioning Character displacement: resource partitioning leads to morphological differences ***Symbiotic relationships Symbiosis: close association between species pairs, where at least one species always benefits 1.Mutualism: +/+ 2.Commensalism: +/0 3.Parasitism: +/- DEFINITIONS Species richness: number of different species Relative abundance: proportion of individuals that belong to each species 2 communities can have same richness but different structures !!Trophic Structure!! -feeding relationships among species o -energy moves up from lower levels o -food chain: producersconsumers (herb) consumers (carn) Energetic Hypothesis: inefficiency of energy transfer between levels DEFINITIONS Dominant species: most abundant or greatest biomass (total of entire population) Keystone species: key niches maintaining community structure ; not necessarily dominant Facilitators: ecosystem engineers **Communities have top-down and bottom-up regulation** 3 Possible relationships between plants and herbivores o Increase in P, decrease in H o Decrease in P, increase in H o Both Bottom up: P H C Top down: P H C **Species richness is maintained by disturbance** -most communities are not in stable equilibrium -nonequilibrium model better characterizes most communities -intermediate disturbance hypothesis: some disturbance increases species diversity !Succession= pattern of species replacement over time DEFINITIONS Ecological succession: first colonizers replaced by other species, which are replaced by other species Primary succession: beginning without soil Secondary succession: with soil *large areas have more species: seen in species- area curve latiudinal gradient: more species closer to the equator ; higher tropical diversity Lecture 40: Ecosystems Synopsis: flow of energy, cycling of nutrients Ecosystem: sum of biotic and abiotic interactions in an area **2 abiotic processes central to ecosystem ecology: 1.Flow of energy 2.cycling of nutrients !!Both energy and nutrients move through trophic levels!! DEFINITIONS Primary producers: autotrophs Primary consumers: herbivores that eat producers Secondary consumers: carnivores that eat herbivores Tertiary consumers: carnivores carnivores that eat carnivores Detrivores/ decomposers: get energy from detritus (non-living organic material) **Production is ultimately limited by the amount of energy that enters the system*** primary production: amount of light energy converted to chemical energy in a given span of time gross primary production: total 1 degree production for an ecosystem net primary production: part stored as organic matter o NPP=Gpp-respiration Secondary production: new biomass added to consumers; amount of 1 degree production converted to consumer if plants had all of the needed nutrients, only limited by light ( because of 1 degree) limiting nutrient: if adding a nutrient increases productivity, then it is limiting eutrophication: increased algal production due to pollution **Different nutrients have independent biogeochemical cycles** Nutrients cycle through ecosystems o Biogeochemical cycles: biotic and abiotic o Inputs/ outputs o Nutrients sometimes present but unavailable Nutrients can be available/ unavailable, organic/inorganic 4 most important cycles o H2O o C o N o P Decomposition= critical for cycling Detrivores break down org. molecules to inorg. So they can be used by 1 degree producers !Humans enrich the Nitrogen cycle for agriculture! -farming removes N -fertilizer adds N -excess runoff Lecture 41: Biodiversity and Conservation Synopsis: major threats to biodiversity o -habitat loss o -invasive species o -overexploitation o -global change Threats to Biodiversity: 1.Habitat loss and destruction a.Biggest threat b.Fragmentation 2.Introduced/ Exotic species a.From increase in global travel ( introduced) b.Alter ecosystems c. Accident/ purpose 3.Overexploitation a.Harvested faster than can reproduce 4.Global change Human activities habitat degradation/ loss Agriculture- primary Natural resource extraction Urbanization/ infrastructure development War and violent conflict Pollution Consequences of Pollution Pollutants not broken down by detrivores=biological magnification: becomes more concentrated in higher trophic levels Naturally occurring chemicals released at unnatural levels Invasive Species: An introduced species that extablishes, expands its range, and has a substantial impact on native organisms and ecosystems. interact with natives as 1.Competitors 2.Predators 3.Parasites Overexploitation Hunting Fishing Fisheries by catch Collecting for trade **Burning fossil fuels acid rain Releases S and N o Combines with water to make sulfuric/ nitric acids Kills acid sensitive fish Source distant from effects *Chemicals WE release CFCs- refrigeration, A/C o Cl reacts with ozone o Ozone breaks down oxygen o Less ozone =less UV protection Hole o DNA damage **Excess CO2 from fossil fuels and increased temp. CO2, CH4, H2O naturally warm the earth= greenhouse Greatest effect at high latitudes Lecture 42: Conservation Biology Synopsis: Human population growth, human effects, threats Ecological footprint: measures Human impact Biodiversity: biological diversity **anthropogenic (human caused) ecosystem modification is causing increased extinction rates Biophilia: innate tie to nature Most common: extinction of species -preservation of species genetic diversity necessary for future adaptation to changing environment -community and ecosystem diversity: fates of species interconnected Lecture 43: Conservation and Restoration Synopsis: approaches to conservation, restoration ecology, sustainability ***Efforts to protect species revolve around keeping their numbers from getting too low*** Endangered- when population gets too small o Extinction vortex: small populations lead to smaller populations which lead to extinction o Minimum viable population (MVP) size: number of individuals at which a species is able to sustain its # and not enter the vortex. Depends on species o Use effective population size rep. estimated length !!More efficient to focus on landscapes and habitats than species!! Areas= multiple species o Large tracts of land to protect against fragmentation Edges: boundaries between communities or ecosystems Edge effects: increase due to habitat fragmentation Corridors: strips of habitat that connect otherwise isolated habitat fragments, facilitates movement and dispersal. Biodiversity hot spots= smaller areas with lots of diversity Restoration ecology restoring ecosystems too far degraded Bioremediation: using plants, fungi, prokaryotes etc. to detoxify an area Biological augmentation: use organisms to add compounds to ecosystem
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