Understanding Ecology: Interactions and Evolutionary Change

1. Unit II: Ecology and Animal Behavior Ecological interactions affect how organisms evolve, and evolutionary change in turn affects ecological relationships.

2. Ecology • Ecology • the study of the relationships between organisms and their environment • + two types of interactions • - biotic (living) • - abiotic (nonliving) • + levels of study • - population, community, ecosystem, biosphere • Population Ecology • + population: group of individuals all of the same species living in • the same area • - describing abundance/distribution of populations • + size (total number of individuals = N) • + density (total number of individuals per area/volume) • + dispersion (clumped, uniform, random)

3. Age Structure Sweden- relatively stable population growth Mexico- rapidly growing population United States- relatively stable population growth

4. Survivorship Curves Type I: most individuals die old Type II: length of survivorship is random Type III: most individuals die young

5. Population Growth • Biotic potential • maximum growth rate of population under ideal conditions • Carrying Capacity (K) • maximum number of individuals a population can sustain • + limiting factors • - elements that prevent a population from attaining • its biotic potential

6. Density-dependent Factors • Density-dependent factor • intensifies as population increases • + reduce the population growth by • decreasingreproduction or by • increasingmortality • - parasites/disease, competition, • predation, stress Density-independentFactors Density-independent factor occurs independently of population; unrelated to population size + natural disasters and extremes of climate

7. Exponential Growth J-shaped curve

8. Logistic Growth • Logistic Growth • occurs when limiting • factors restrict the size • of the population to • the carrying capacity (K) S-shaped/sigmoid curve

9. Community Ecology • Community Ecology • looking at the interactions between populations • - positive (+), negative (-), or neutral (0) • + types • - Competition • - Predation • - Symbiosis

10. Competition • Competition (-/-) • interaction between individual organisms that use the same resources • present in limited supply • niche: set of resources/conditions necessary for survival • + organism’s role/job in the community • - intraspecific / interspecific competition • + same / different species

11. Predation • Predation (+/-) • eating of live or freshly killed organisms • + parasitism • - specialized predators do not actually kill prey (host) • + Defense against Predators • cryptic coloration (camouflage) • aposematic coloration (warning coloration) • mimicry • + Batesian (harmless species mimics harmful model) • + Mullerian (harmful species resemble each other)

12. Symbiosis • Symbiosis • close and long term association between organisms of two species • + Mutualism (+/+) • - both organisms benefit from the interaction • + mycorrhizae, lichens • + Commensalism (+/0) • - one species benefits, but other is unaffected • + remora-shark relationship

13. Community Composition and the Question of Stability • Disturbances • events, such as storms, fire, floods, droughts, overgrazing, etc. • + damage community, remove organisms, alter resource availability • - communities are usually in a state of recovery • Ecological Succession • change in the composition of species over time • + climax community • - final successional stage of constant species composition • + changes that induce succession • - substrate texture • - soil pH • - soil water potential • - light availability • - crowding

14. Primary Succession • occurs on substrates that never previously supported living things + Ex.) rock or lava • - lichens • - bacteria, protists, mosses • - insects, other arthropods Secondary Succession • begins in habitats where communities were destroyed by disturbances • + abandoned cropland

15. Ecosystems • Trophic Levels • Primary producers • + autotrophs (plants, protists, cyanobacteria, • Primary consumers • + herbivores • Secondary consumers • + primary carnivores • Tertiary consumers • + secondary carnivores • Detritivores • + decomposers (fungi, bacteria, • earthworms, insects, • scavengers)

16. Pyramid of Energy

17. Ecological Efficiency • Ecological Efficiency • proportion of energy • represented at one trophic level • that is transferred to the next • + average efficiency=10% • - only 10% of productivity • is transferred to next level • - remaining 90% is • consumed by metabolism

18. Biogeochemical Cycles • Biogeochemical Cycles • flow of essential elements from the environment to living things and • back to the environment • + reservoirs • - major storage locations • + assimilation • - processes through which element incorporates into • terrestrial plants and animals • + release • - processes through which element returns to the environment

19. Hydrologic Cycle (water cycle) Reservoirs: oceans, air, groundwater, glaciers Assimilation: plants absorb from soil; animals eat/drink Release: plants transpire; animals/plants decompose

20. Carbon Cycle Reservoirs: atmosphere (CO2), fossil fuels, peat, cellulose Assimilation: plants via photosynthesis; consumers Release: respiration and decomposition; burn fossil fuels

21. Nitrogen Cycle Reservoirs: atmosphere (N2); soil (ammonium, ammonia, nitrite, nitrate) Assimilation: plants absorb from soil; animals consume plants/animals Release: denitrifying and detrivorous bacteria; animal excretion

22. Phosphorous Cycle Reservoirs: rocks Assimilation: plants absorb from soil (phosphate); consumers Release: decomposition; excretion in waste products

23. Biome region of biosphere characteristized by vegetation and adaptations of organisms inhabiting the environment + Tropical rain forest (high temp., heavy rainfall) + Savannahs(grassland with scattered trees) - tropical, but receive less rainfall than rain forest + Temperate grasslands (North American prairie) - receive less water/lower temp. than savannahs + Temperate deciduous forests (warm summer/cold winters) Biomes

24. Biomes Cont’d Deserts(hot and dry) Taigas (coniferous forests) - precipitation in the form of snow Tundras) - permafrost Fresh water biomes (ponds, lakes, streams, rivers) + Marine biomes (estuaries, intertidal zones, continental shelves, • coral reefs, pelagic oceans)

25. Ethology • the study of animal behavior • kinds of animal behavior • - Innate Behavior • + instinct • + fixed action patterns or FAP (Niko Tinbergen) • + imprinting* (Konrad Lorenz) • - Learned Behavior • + associative learning • - classical conditioning (Ivan Pavlov) • - operant conditioning (B.F. Skinner) • + habituation • + observational learning • + insight Animal Behavior

26. Animal Movement • Kinesis • undirected change in speed of movement in response to stimulus • + speed up in unfavorable; slow down in favorable • - light, touch, air temp., etc. • + Avon bug in the bathroom tub • Taxis • directed movement in response to stimulus • + toward/away from stimulus • - phototaxis, chemotaxis • + mosquitos and CO2 • Migration • long-distance, seasonal movement

27. Chemical • pheromones • + releaser pheromones cause immediate/specific behavioral changes • + primer pheromones cause physiological changes • - marking your territory • Visual • agonistic behavior • + displays of aggression • courtship behavior • + announce participants as non-threatening/potential mates • Auditory • sounds • + whales, crickets, birds • Tactile • touching Communication in Animals

28. Social Behavior • Agonistic Behavior • aggression/submission • + competition for food, mates, territory • + ritualized; reduces injury/energy • Dominance Hierarchies • power and status relationships among groups • + minimize fighting for food/mates • Territoriality • possession/defense of territory • + insures adequate food/space • Altruistic Behavior • unselfish behavior that appears to reduce fitness • + increases inclusive fitness