Final BIO122 Flashcards
Ecology
Study of how organisms interact with each other and their environment. Both biotic and abiotic.
Biotic
How organisms interact with each other.
Interspecies vs intraspecies interactions.
Interspecies
- Predator/prey interactions
- Competition with other species
Intraspecies
- Mating behavior
- Herd dynamics
- Distribution
- Competition within the species
Abiotic
How organisms interact with physical factors.
Physical factors influence attributes of a species.
Some hierarchical levels of life:
Global ecology, landscape ecology, ecosystem ecology, community ecology, population ecology, organismal ecology.
Example: Global ecology - How are ecological changes altering Earth?
How has ecology had a great influence over our understanding of evolution?
Considering aspects of ecology (i.e. competition) led to the theory of natural selection.
Why do organisms live where they do? (Population level question)
- Interactions with the environment shape organisms through natural selection.
Organisms might live in an area because they have spent many generations adapting to that environment. - Migration can bring organisms to new environments.
Organisms might live in an area that they migrate to and are “pre-adapted” for.
What determines the structure of an ecosystem? Top-down vs bottom-up (community level question).
Top-down: The abundance of apex predators determines the structure of the ecosystem.
Bottom-up: The amount for primary production (plant-growth) determines the structure of the ecosystem.
What determines how diverse an ecosystem is? (Ecosystem level question)
Tropical regions have more biodiversity than anywhere else on earth.
Polar regions have very little biodiversity.
Abiotic - extinction is less likely to happen in tropics bc rainfall and the terrain is variable.
Biotic - By chance the tropics became biodiverse and since have maintained bc of frequency of ecological interactions between species.
____ and ____ establish abiotic factors on earth.
Geology, physics
What establishes regional climate patterns?
Solar radiation.
How do seasons come about.
Seasons result from the earth’s rotation being offset from the angle of its orbit around the sun.
Tropics receive more or less sunlight year round.
How does local geology also alter climactic conditions?
Prevailing temperature, wind, and precipitations set the overall climate of a region.
Mountain ranges, bodies of water, or other features of geology can alter that climate.
Proximity to water influences…
Terrestrial Climate
What are terrestrial ecosystems mostly determined by?
Annual temperature and rainfall.
Movement of air leads to rainfall and temperature regimes for a region.
____ factors establish climates.
Abiotic
Marine ecosystem types are established by…
Availability of light and nutrients.
Very little organic matter is present deep in the ocean because…
Lack of nutrients and sun light.
Most organisms are dependent on matter that “rains down” from above.
Some deep-water ecosystems are dependent on geochemical energy.
What is behavior?
The study of how animals respond to their environment.
Includes everything from reflex movement to personality traits.
What are the four questions to thoroughly understand a behavior?
Proximate Questions: Who/what/how of a behavior (mechanistic understanding)
1. What mechanisms trigger a specific response?
2. How does the expression of a behavior develop as the animal matures?
Ultimate Question: Why of a behavior (evolutionary significance)
3. What is the ecological function of the behavior and how does it aid survival and reproduction?
4. How did the behavior evolve?
Imagine you are studying pack hunting behavior in wolves. If you asked the question: “Is pack hunting adaptive?” - Would that be a proximate or ultimate question?
a. Proximate
b. Ultimate
Ultimate
Beware of the adaptationists explanation…
Interpreting the evolution of a character by interpreting its function assumes the character evolved through adaptation, which often leads to just-so stories.
Innate behaviors are ____, ____, or ____.
fixed, hardwired, reflective.
Example of innate behavior..
Spiders that weave webs are born knowing how to weave a web.