AP Biology Summer Work Notes PDF

Unit 8: Ecology 8.1 - Animal Behavior Video Notes ​ Organisms respond to their environment with their behaviors and physiology ○​ Stimulus: an external signal that causes a response in an organism ​ Tropism ​ Displayed by plants...

Unit 8: Ecology 8.1 - Animal Behavior Video Notes ​ Organisms respond to their environment with their behaviors and physiology ○​ Stimulus: an external signal that causes a response in an organism ​ Tropism ​ Displayed by plants ​ Growth toward (positive) or away from (negative) a stimulus ○​ Positive Phototropism: plants growing towards sunlight ○​ Gravitropism: roots grow down ​ Taxis ​ Displayed in animals ​ Behavior directed toward or away from something ​ Kinesis ​ Displayed in animals ​ Random movement ​ External and internal signals may cause communication behaviors between organisms ○​ Benefit the survival and reproductive success of the group ​ Animals communicate through _______ signals ○​ Visual ​ Ex: poisonous creatures are often brightly colored (aposematic coloration) ○​ Tactile ○​ Audible ○​ Electrical ○​ Chemical ​ Ex: animals marking their territory and/or attracting mates by scent ​ Animals communicate to… ○​ Indicate dominance ○​ Find food ○​ Establish territory ○​ Ensure reproductive success ​ Groups of animals often cooperate ○​ Ensures survival of the group at large ○​ May intimidate predators ○​ Individual organisms often take on different roles in the group ​ Natural Selection favors innate and learned behaviors that increase the chances of survival and reproduction ○​ Innate Behavior: genetically controlled and happen without prior knowledge or experience ​ Ex: instincts, reflexes  ○​ Learned Behavior: developed as a result of experience Textbook Notes Chapter 51 ​ Behavior: Action carried out by muscles under control of the nervous system ○​ Essential to animal survival and reproduction ○​ Subject to natural selection ​ Behavioral Ecology: the study of the ecological and evolutionary basis for animal behavior ​ Discrete sensory inputs can stimulate both simple and complex behaviors ​ According to Dutch scientist Niko Tinbergen, to understand behavior, one must answer these questions: ○​ What stimulus elicits the behavior and what physiological mechanisms mediate the response? ○​ How does the animal’s experience during growth and development influence the response? ○​ How does the behavior aid survival and reproduction? ○​ What is the behavior’s evolutionary history? ​ Types of Causation: ○​ Proximate: how a behavior occurs or is modified ○​ Ultimate: why a behavior occurs in the context of natural selection ​ Fixed Action Pattern: a sequence of unlearned acts directly linked to a simple stimulus ○​ Ex: Male stickleback fish, which have red bellies, act aggressively towards anything that is red as they automatically assume it is another male trying to take over their territory ○​ Sign Stimulus: external cue that triggers a behavior ​ Migration: a regular, long-distance change in location, typically occurring as a result of environmental stimuli ○​ Animals can use the sun/stars or Earth’s magnetic field to find their way ​ Behavioral Rhythms ○​ Circadian Rhythm: sleep-wake cycle, typically dependent on light availability ○​ Circannual Rhythm: behavioral rhythms linked to the seasonal cycle; also influenced by light availability ​ Signal: stimulus transmitted from one organism to another ​ Communication: the transmission and reception of signals between animals ○​ Four common modes of animal communication: visual, chemical, tactile, auditory ​ Stimulus-Response Chain: the response to one stimulus is the stimulus for the next behavior ​ Pheromones: chemical substances with distinct odors or tastes that certain animals emit ​ Learning establishes specific links between experience and behavior ​ Cross-Fostering Study: when the young of one species are placed in the care of adults from another species in the same/similar environment ○​ Nature vs. nurture ○​ Similar to human twin studies that study the differences between identical twins raised apart from each other versus those raised together ​ Learning: the modification of behavior as a result of experience ​ Imprinting: the establishment of a long-lasting behavioral response to a particular individual or object ○​ Occurs commonly in young animals ○​ Can only take place during the sensitive period of development ​ Spatial Learning: the establishment of a memory that reflects the environment’s spatial structure ○​ Cognitive Map: a representation in an animal’s nervous system of spatial relationships between objects in its surroundings ​ Associative Learning: the ability to associate one environmental feature with another ○​ Classical and operant conditioning ○​ Associations can be formed based on what is naturally occurring ​ Ex: animals will likely not jo associate poisonous food with noise but will with color ​ Cognition: the process of knowing that involves awareness, reasoning, recollection, and judgment ○​ Involved in the most complex forms of learning ○​ Problem Solving: the cognitive activity of devising a method to proceed from one state to another in the face of real or apparent obstacles ​ Most learned behaviors develop rather quickly ​ Social Learning: learning through observing others ○​ Forms the roots of culture: A system of information transfer through social learning or teaching that influences the behavior of individuals in a population ​ Selection for individual survival and reproductive success can explain diverse behaviors ​ Foraging: food-obtaining behaviors ○​ Optimal Foraging Model: natural selection should favor a foraging behavior that minimizes the costs and maximizes the benefits ​ Risk of predation is a significant cost ​ Mating Systems ○​ Promiscuous: no strong pair-bonds ○​ Monogamous: one male mating with one female ○​ Polygamous: an individual of one sex mating with several members of the other sex ​ Polygyny - 1 male ​ Polyandry - 1 female ​ Sexual Dimorphism: the degree of physical difference between male and female members of a species ○​ Monogamous species have low sexual dimorphism, while the opposite is true for polygamous species ​ Some animals with offspring dependent on their parents are monogamous because 2 parents raising offspring increases the likelihood of the offspring surviving ○​ Less common in species whose offspring can care for themselves ​ Because almost all species have low certainty of paternity, many males have a lower involvement in raising offspring than females ○​ Certainty of paternity is high when eggs are externally fertilized ​ Sexual Selection: ○​ Intersexual: members of one sex choose mates based on characteristics ○​ Intrasexual: members of one sex compete for the chance to mate  ○​ Mate-choice Copying: individuals in a population copy the mate choice of others ​ If a female guppy sees another female guppy with a male, she is likely to also try to mate with that male regardless of its survival advantage over other viable males ​ Form of social learning ​ Genetic analyses and the concept of inclusive fitness provide a basis for studying the evolution of behavior ​ Genes predispose individual creatures to behave in certain ways and even have distinct taste preferences ​ Altruism: a behavior that reduces an animal’s individual fitness but increases the fitness of others in the population ○​ Ex: Worker bees are infertile but can help the queen ​ Inclusive Fitness: the total effect an individual has on proliferating its genes by producing its own offspring and by aiding relatives in order to enable them to reproduce ○​ B (benefit): average number of extra offspring produced by the recipient of an altruistic act ○​ C (cost): how many fewer offspring the altruist produces ○​ R: coefficient of relatedness ​ Hamilton’s Rule: rB > C ○​ In these scenarios, natural selection favors altruism ​ Kin Selection: natural selection that favors altruism by enhancing the reproductive success of relatives ​ Reciprocal Altruism: when an individual offers aid to a non-related individual if the recipient returns the favor in the future ○​ Rare in non-humans ○​ Cheating: not returning the favor, which can result in negative consequences ​ Play: behavior that seems purposeless ○​ Object: playing with an object ○​ Locomotor: playing by moving around (running, skipping, etc.) ○​ Social: interacting with others of the same species ​ Some scientists believe play serves as preparation for unexpected events ​ Sociobiology: believing that certain behavioral characteristics exist because they are expressions of genes that have been perpetuated by natural selection Slides Slide 16 (Question A): If C. elegans can detect the location of a food source or determine that it is of higher quality, it is likely to direct its movement towards it; this type of directed movement is known as taxis. If C. elegans cannot detect the location or quality of a food source, it is more likely to move randomly to find food; random movements displayed by animals are known as kinesis. Slide 18 (Question B): The scientists’ use of two different spots on the petri dish is justified as one spot represents the experimental group, which contains chemicals produced by the prey of C. elegans, while the other is the control group and contains no such chemicals. By counting the number of worms at each location, scientists can either confirm or reject the hypothesis that C. elegans is attracted to chemicals produced by their prey. If there are significantly more worms in the number of worms at the spot with the chemical, the hypothesis is confirmed; if the opposite is true, the hypothesis is rejected; and if the number of worms is relatively equal, the test is inconclusive. 8.2 - Energy Flow Through Ecosystems Video Notes ​ Organisms use energy to grow, keep homeostasis, and reproduce ​ Endothermic Organisms: maintain homeostasis by using thermal energy from metabolic processes ○​ Also known as warm-blooded organisms ○​ Typically an inverse relationship between the size of an organism and its metabolic rate ​ Smaller animals find it harder to keep warm ​ Ectothermic Organisms: do not have the ability to regulate their body temperature ○​ Also known as cold-blooded organisms ○​ Must alter behavior to change their body temperature ○​ Typically smaller than endotherms ​ Organisms have different reproductive strategies in response to energy availability ○​ Many Offspring: constantly changing environment with scarce resources ​ R-selected Species ○​ Few Offspring: more energy efficient; occurs in more stable environments ​ K-selected Species ​ Seasonal reproduction occurs at different times of the year in plants and animals ○​ Plants release the most pollen when pollinators are the most active ○​ Animals reproduce in spring and summer when food is more plentiful ​ Trophic Structure: determined by the feeding relationships between organisms ○​ Trophic Levels: links in the trophic structure ○​ Food chain ​ The length of food chains is limited because… ​ Energetic Hypothesis: Only 10% of the energy is transferred up trophic levels, reaching low numbers at the top predators ○​ The rest is lost as heat ​ Long food chains are typically less stable than short ones ​ Autotrophs make their own organic compounds for energy through photosynthesis (solar energy) or chemosynthesis (chemical energy) ​ Heterotrophs consume other organisms for their energy ○​ Metabolize carbs, lipids, and proteins through hydrolysis ​ Food Webs: 2+ food chains linked together​ ○​ Species may weave into the web at more than one trophic level Textbook Notes Chapter 52 ​ Ecology: the scientific study of the interactions between organisms and the environment ○​ Levels: organismal, population, community, ecosystem, landscape, global ​ Earth’s climate varies by latitude and season and is changing rapidly ​ Climate: the long-term prevailing weather conditions in a given area ○​ Key Factors: temperature, precipitation, sunlight, wind ​ Global climate patterns are determined largely by the input of solar energy and Earth’s movement in space ​ Influences on Climate ○​ Earth’s tilt causes seasonal cycles in middle to high latitudes ○​ Ocean currents heat/cool air that passes over land ​ Coastal areas are also typically wetter ○​ Mountains typically cool air ​ Microclimate: fine, localized patterns of climate conditions ​ Abiotic Factors: nonliving factors that influence environment ​ Biotic Factors: living factors that influence environment ​ Climate Change: a directional change to the global climate that lasts 3+ decades ○​ Occurs naturally and as a result of human activity ​ The distribution of terrestrial biomes is controlled by climate and disturbance ​ Biomes: major life zones characterized by vegetation type or the physical environment ○​ Either terrestrial or aquatic ○​ Ecotone: area of overlap between nearby biomes ​ Climograph: plot of the annual mean temperature and precipitation in a region ​ Disturbance: an event that changes a community by removing organisms and/or altering resource availability ​ Aquatic biomes are diverse and dynamic systems that cover most of Earth ​ Aquatic biomes vary less based on latitude but rather all types can be found anywhere ​ Zones ○​ Photic: upper level of water; significant light for photosynthesis ○​ Aphotic: little light ​ Abyssal: 2k-6k m below surface ○​ Pelagic: photic and aphotic zones combined ○​ Benthic: very bottom ​ Occupied by communities of organisms collectively called the benthos ​ Often eat dead organic matter called detritus ​ Thermocline: layer of abrupt temperature chain that separates the upper and lower layers of most oceans and lakes ○​ Turnover: semiannual mixing of waters of different temperatures in some lakes ​ Interactions between organisms and the environment limit the distribution of species ​ Both biotic and abiotic factors affect where species live and why ​ Dispersal: the movement of individuals or gametes away from their area of origin or from areas of high population density ○​ Range Expansion: when organisms reach an area they did not previously inhabit ○​ Transplant: the addition of a species to a new habitat ​ In order for a transplant to be successful, species must survive and efficiently reproduce in their new habitat  ​ Abiotic Factors that can influence species distribution: temperature, water (indirectly affects oxygen), salinity (affects osmosis), oxygen, sunlight, rocks/soil (pH and mineral composition) ​ Ecological change and evolution affect one another over long and short periods of time Chapter 54 ​ Community: a group of populations of different species living in close enough proximity to interact with each other ​ Community interactions are classified by whether they help, harm, or have no effect on the species involved ​ Interspecific Interactions: interactions between members of different species ○​ Competition, predation, herbivory, parasitism, mutualism, commensalism ​ Exploitation: a general term for any +/- interaction in which one species feeds on another ○​ Prey often develop defense mechanisms to avoid predation ​ Aposematic Coloration: bright colors which warn of poison or bad taste ​ Cryptic Coloration: camouflage ​ Batesian Mimicry: a harmless species mimics a harmful species to which it is not closely related ​ Müllerian Mimicry: two harmful species resemble each other ​ Plants are often toxic or have spikes to avoid being eaten ​ Competitive Exclusion: when a reproductive advantage in one species leads to the elimination of the inferior competitor ​ Ecological Niche: the specific set of biotic and abiotic resources that an organism uses in its environment ○​ Two species cannot coexist permanently if they have an identical niche ○​ Resource Partitioning: the differentiation of niches that enables similar species to coexist in a community ○​ Fundamental Niche: the niche potentially occupied by a species ​ Realized Niche: the portion of the fundamental niche that is actually occupied by the species ​ Allopatric: geographically separate ​ Sympatric: geographically overlapping ​ Character Displacement: tendency for characteristics to diverge more in sympatric than in allopatric populations of two species ​ Parasitism (+/-): Parasites derive nutrition from hosts ○​ Endoparasites live inside their host ○​ Ectoparasites feed on the external surface of their host ○​ Can directly or indirectly cause death ​ Positive Interactions: +/+ or +/0 ○​ Mutualism and commensalism ​ Diversity and trophic structure characterize biological communities ​ Species Diversity: the variety of different kinds of organisms that make up the community ○​ Species Richness: the number of different species in the community ○​ Relative Abundance: the proportion of the whole community that each species represents ​ Shannon Diversity: H = -(pAlnpA + pBlnpB + pClnpC +...+ pnlnpn) ○​ A, B, C … N: species in the community  ○​ P: relative abundance of each species ○​ Higher H value means more diversity ​ Higher diversity is important because it… ○​ Leads to more biomass ​ Biomass: total mass of all the organisms in a habitat ○​ Increases the resistance of communities to invasive species ​ Species Importance ○​ Dominant Species: species with the highest biomass (most abundant) ○​ Keystone Species: species that are not usually abundant but play important ecological roles ○​ Ecosystem Engineers: species that dramatically alter their environment ​ Bottom-Up Model: influence that lower trophic levels have on higher ones ○​ More grass = more deer ​ Top-Down Model: influence that higher trophic levels have on lower ones ○​ More deer = less grass ○​ Trophic Cascade Model: N ←V ← H ← P ​ Disturbance influences species diversity and composition ​ Stability: a community’s tendency to reach and maintain a relatively stable species composition ​ Nonequilibrium Model: most communities are constantly changing after disturbances ​ Intermediate Disturbance Hypothesis: moderate levels of disturbance foster greater species diversity than do high or low levels of disturbance ​ Ecological Succession: when species are gradually replaced by other species ○​ Primary Succession: when ecological succession occurs in a previously lifeless area ​ Typically, prokaryotes are the only organisms initially present ​ Early arrivals will either facilitate (help), inhibit (hurt), or tolerate (grow independently of) other species ○​ Secondary Succession: when an existing community is partially, but not all the way, cleared ​ Typically soil and plants remaining ​ New community may resemble original one ​ Biogeographic factors affect community diversity ​ Latitudinal Gradient: plant and animal life tends to be more abundant in the tropics (close to the equator) than further north/south ○​ Tropical communities are typically older than those in extreme climates, allowing for more species diversity ○​ Also have more sunlight and precipitation ​ Can be studied by evaluating evapotranspiration: the evaporation of water from soil and plants ​ Species-Area Curve: if all other factors are equal, a larger area = more species diversity ○​ S = cAZ ​ S = number of species in a habitat ​ c = constant ​ A = area of habitat ​ Z = species:area ratio  ​ The number of species on an island (i.e. in an isolated habitat) represents a balance between the immigration of new species and extinction of old ones ○​ Immigration rate decreases with increased species diversity, while extinction rates increase ○​ Influenced by size and distance from the mainland ○​ Island Equilibrium Model: rate of species immigration equals rate of extinction ​ Pathogens alter community stricture locally and globally ​ Pathogens: disease-causing microorganisms, viruses, viroids, or prions ○​ Exacerbated by human activity to humans from other animals ​ Can be direct or through intermediate species called vectors ​ Zoonotic Pathogens: transferred Slides Slide 35: D Slide 37: Slide 39: I predict that the spraying of the fungus will have the greatest short-term effect on stoneflies, since 90% of their diet consists of midges. As a result of the fungus, stoneflies are losing almost all of their food source, while both caddisflies and hellgrammites are losing less than half of theirs. 8.3 - Population Ecology Video Notes ​ Population: a group of individuals of the same species living in the same area ○​ Interact and breed with one another frequently ​ Adaptations in organisms are related to obtaining and using energy in a particular environment ​ Population size depends on these factors ○​ Food availability ​ More = larger population; higher reproduction and survival rates ​ Organisms have different adaptations to deal with a lack of available food  ​ Hibernation, migration, etc. ​ Population Growth: dN/dt = B - D ○​ dN: change in population size ○​ dt: change in time ○​ B: birth rate ○​ D: death rate ​ Exponential Growth: unlimited resources ○​ Growth at a constant rate ​ Number of new organisms grows with population ○​ Represented by a J curve ○​ dN/dt = rmaxN ​ rmax: maximum per capita growth rate of population (intrinsic rate of increase) ​ N: population size (B - D) Textbook Notes ​ Population Ecology: the study of populations in relation to their environment ​ Biotic and abiotic factors affect population density, dispersion, and demographics ​ Ecologists typically define populations based on boundaries ​ Dispersion: the pattern of spacing among individuals within the boundaries of a population ○​ Clumped: individuals aggregated in patches ​ Territoriality: the defense of a bounded physical space against encroachment by other individuals ○​ Uniform: evenly spaced ○​ Random: positioning of individuals is independent of others ​ Immigration: the influx of new individuals into a population ​ Emigration: the movement of individuals out of a population ​ Demographics: the study of vital statistics of populations (birth, death, migration rates) over time ○​ Life Table: summarizes the survival and reproductive rates of individuals in specific age-groups within a population ​ Cohort: group of individuals of the same age ​ Typically tracked from birth to death ○​ Survivorship Curve: a plot of the proportion or numbers in a cohort still alive at each stage ​ Types I, II, and III ​ Demographers often focus on the females of a population ○​ Number of breeding females in a population  ○​ Reproductive Output: average number of female offspring produced by the females in a given age group ​ The logistic model describes how a population grows more slowly as it nears its carrying capacity ​ Life history traits are products of natural selection ​ Life History: traits that affect an organism’s schedule of reproduction and survival ○​ When reproduction begins, how often the organism reproduces, how many offspring are produced per reproductive cycle ○​ Trade-offs between all three factors ​ Semelparity: organism reproduces once ​ Iteroparity: repeated reproduction ​ K-selection: selection for traits that are advantageous at high densities ​ R-selection: selection for traits that are advantageous at low densities ​ Population Dynamics: population fluctuations from year to year/place to place ○​ Some occur randomly, while others occur in cycles ​ Metapopulations: when a number of large populations are linked ​ The human population is no longer growing exponentially but is still increasing rapidly ​ Demographic Transition: the movement from high birth/death rates to low ones, which accompanies industrialization and improved living conditions ​ Age Structure: the relative number of individuals of each age in the population ​ Ecological Footprint: summarizes the aggregate land and water area required by each person, city, or nation to produce all the resources it consumes and to absorb all the waste it generates Slides Slide 48: dN/dt = rmaxN dN/dt = (1.3)(2500) = 3250 3250 mice are added to the population each year Slide 49: dN/dt = B - D dN/dt = 500 - 75 = 425 dN/dt = rmaxN 425 = (rmax)(2500) rmax = 425/2500 = 0.17 8.4 - Logistic Growth Video Notes ​ Density: number of individuals per unit area or volume ○​ Typically determined by sampling or the mark-recapture method ○​ Influenced by abiotic and biotic factors ​ Density Independent: birth/death rate does not change with population density ​ Ex: natural disasters ​ Density Dependent: birth/death rate does change with population density ​ Regulated: when one or more density-dependent factors can cause a small population to grow or vice versa ​ Ex: predator populations depend on the availability of prey ​ Logistic Growth: slow growth, followed by exponential growth which eventually tapers off ○​ S-curve ​ Logistic Growth Model: dN/dt = rmaxN(K-N)/K ○​ Carrying Capacity (K): maximum population size that a particular environment can sustain ​ Varies over space and time and with the abundance of resources Textbook Notes SEE UNIT 8.3 Slides Slide 61: dN/dt = rmaxN(K-N)/K 75 = (rmax)(150)(275-150)/275 75 = (rmax)(150)(125)/275 20625 = (18750)rmax rmax = 1.1 8.5 - Biodiversity Video Notes ​ Community: a group of different species living in the same are and interacting with each other ○​ All living things ​ Species Diversity: the variety of species and the quantity of individuals included in each species within a given community  ○​ “Increase diversity = increase stability” ​ Species Composition: the identity of each species in the community ​ Simpson’s Diversity Index ○​ Higher number (closer to 1) = more diversity/stability ○​ 1 - 𝚺 (n/N)2 ​ n = total number of organisms in a particular species ​ N = total number of organisms ​ Interactions among populations determine how they access energy and matter ○​ Competition, mutualism, commensalism, parasitism ○​ Symbiotic Relationships: organisms need each other to survive ​ Live in close proximities ​ Trophic Cascade: the negative effect the removal/decrease of a key species has on other trophic levels ​ Niche Partitioning: a decrease in competition over limited resources between two similar species because each species is accessing the resource in different ways Textbook Notes ​ Ecosystem: the sum of all the organisms living in a given area and the abiotic factors with which they interact ○​ Two key emergent properties: energy flow and chemical cycling ​ Physical laws govern energy flow and chemical cycling in ecosystems ○​ First Law of Thermodynamics: energy cannot be created or destroyed, only transferred or transformed ○​ Law of Conservation of Mass: matter cannot be created or destroyed ​ Trophic Levels ○​ Primary Producers: convert solar energy into chemical energy ○​ Secondary Consumers: eat primary producers (herbivores) ○​ Tertiary Consumers: eat secondary consumers (carnivores that eat herbivores) ○​ Quaternary Consumers: eat tertiary consumers (carnivores that eat carnivores) ​ Plant → Bug → Mice → Eagle ○​ Detritivores (Decomposers): eat nonliving organic material (detritus) ​ Energy and other limiting factors control primary production in ecosystems ​ Primary Production: the amount of light energy converted into chemical energy by autotrophs during a certain time period ​ Gross Primary Production (GPP): the amount of light or chemical energy converted into the chemical energy of organic molecules per unit time ​ Net Primary Production (NPP): GPP minus the energy used by autotrophs for their cellular respiration ○​ NPP = GPP - Ra ○​ Typically about ½ of GPP ​ Net Ecosystem Production (NEP): measure of the total biomass accumulated during a period of time (not just primary producers) ○​ NEP = GPP - RT ​ Limiting Nutrient: element that must be added for production to increase ​ Eutrophication: the loss of oxygen in underwater ecosystems due to detritivores consuming most of the oxygen in dead autotrophs ​ Energy transfer is between trophic levels is only 10% efficient ​ Production Efficiency: the percentage of energy stored in assimilated food that is used for growth and reproduction, not respiration ○​ 100 × {Net secondary production (J)/Assimilation of primary production (J)} ​ Trophic Efficiency: percentage of energy transferred up each trophic level ○​ Range from 5-20% ○​ Typically around 10% ○​ Loss of energy represented in energy pyramids ​ Biomass Pyramid: represents total amount of biomass at each trophic level ​ Biological and geochemical processes cycle nutrients and water in ecosystems ​ Decomposition replenishes the pools of inorganic nutrients that plants and other autotrophs use to build organic matter ​ Biogeochemical Cycles: nutrient cycles (contain both biotic and abiotic factors) ○​ Carbon, nitrogen, oxygen ​ Restoration ecologists return degraded ecosystems to a more natural state ​ Bioremediation: using organisms (plants, fungi, prokaryotes) to detoxify polluted ecosystems ​ Biological Augmentation: uses organisms to add essential materials to a degraded system ​ Conservation Biology: integrates ecology, physiology, molecular biology, evolutionary biology, and genetics to conserve biological diversity at all levels ​ Human activities threaten Earth’s biodiversity ​ Biodiversity’s levels ○​ Genetic: within a population and between populations of the same species ○​ Species: within an ecosystem ​ Endangered species: in danger of extinction throughout most/all of its range ​ Threatened species: likely to become endangered in the near future ○​ Global: between ecosystems ​ Ecosystem services: all the processes through which natural ecosystems help sustain human life ​ Major threats to biodiversity as a result of human activity include habitat loss, introduced species, overharvesting, and global change ​ Overharvesting : the harvesting of wild organisms at rates exceeding the ability of their populations to rebound ​ Population Conservation focuses on population size, genetic diversity, and critical habitat ​ Extinction Vortex: the decrease of genetic diversity (possibly due to inbreeding in small populations) that leads to extinction ​ Minimum Viable Population Size: minimal population size that allows a species to maintain its numbers ○​ Effective Population Size: the number of organisms within a population that can reproduce​ ​ ​ ​ ​ ` ○​ Determined by the following equation: Ne = 4NfNm/(Nf + Nm) ​ F, M = number of females and males respectively ​ Declining-Population Approach considers populations whose numbers are declining, regardless of how close they are to their minimum viable population size  ​ Landscape and regional conservation help sustain biodiversity ​ Structure: physical features of a landscape ​ Edges: boundaries between ecosystems ○​ has its own set of physical conditions ​ Fragmentation: the splitting of one ecosystem into several small ones ○​ can benefit populations that live in edges ​ Movement Corridor: narrow strip or series of small clumps of habitat connecting otherwise isolated patches ​ Governments often establish protected patches to preserve biodiversity ​ Biodiversity HotSpot: relatively small area with numerous endemic (found nowhere else in the world) species ​ Zoned Reserve: extensive region that includes areas that have been changed by human activity and are used for economic gain ​ Urban Ecology: examines organism and their environment in urban settings ​ Earth is changing rapidly as a result of human actions ○​ Removal of nutrients ​ Critical Load: the amount of added nutrient (N or P) that can be absorbed by plants without damaging ecosystem integrity ○​ Depletion of atmospheric ozone ​ Climate Change: a directional change to the global climate that lasts for 3+ decades ​ Greenhouse Effect: greenhouse gasses trap radiation and radiate most of it back towards Earth ​ Sustainable development can improve human lives while conserving biodiversity ​ Sustainable Development: economic development that meets the needs of people today without limiting the ability of future generations to meet their needs Slides Slide 69: 1 - 𝚺 (n/N)2 1 - {(3/15)2 + (5/15)2 + (7/15)2) 1 - 0.37 = 0.63 8.6/7 - Ecosystem Survival + Invasive Species Video Notes ​ Natural and artificial ecosystems with fewer component parts and with little diversity among the parts are often less resilient to changes in the environment ​ Biotic factors help maintain ecosystem diversity ​ The effects of keystone species are disproportionate relative to their abundance ​ Invasive species affect ecosystem dynamics ○​ Ex: lanternflies ​ The distribution of local and global ecosystems changes over time  ○​ Partly due to human activity: Urbanization, industrialization, etc. ​ Biological Magnification: interruptions to healthy ecosystems at a low trophic level can continue to have effects up the food chain ○​ A bird eventually consumes toxin consumed first by plankton Textbook Notes SEE CHAPTER 8.5