Unit 2 Flashcards
Evolution
Change in a populations gene pool overtime
Convergent evolution
Similar structure resulting from environment
Divergent evolution
Different structures in similar species that result from differences in environment
Mutation
Mistake in dna replication or cell division that causes a change in DNA
Species
A group of organisms that can interbreed and create offspring that can reproduce
Speciation
The process by which new species are generated; commonly through geographic isolation
Natural selection
Individuals that inherit beneficial adaptations produce more offspring
Sexual selection
- Traits that aid in reproducing are selected
- either female choice, or male male competition
Artificial selection
Traits chosen by humans that tend to not serve a survival purpose
Variation (natural selection)
Individuals are different
Overproduction (natural selection)
Many offspring creates competition for resources
Adaptation (natural selection)
Variations in a population allow for some individuals to survive better
Selection (natural selection)
Over time a population will result in adaptations suited to its environment
Keystone species
A species that keeps an ecosystem together and stable , the removal of which has large impacts on the ecosystems (ex. Yellowstone wolves)
Feedback loop
A circular process in which a systems output serves as an input for that same system
Positive feedback loop
Output of system drives the system towards one extreme or another (ex. Glacier melt)
Negative feedback loop
Output of the system drives the system in the opposite direction, stabilizing it. (Ex. body temp regulation)
Biodiversity
Variety of life across all levels of biological organization; higher levels result in more stable ecosystem
Species biodiversity
Variety of species in an area
Genetic biodiversity
Differences in DNA composition
Ecosystem biodiversity
Number and variety of ecosystems
Benefits of biodiversity
- Enhances food security
- Provides drugs and medicines
- Provide ecosystem services
- Maintain functioning ecosystems
- Boosts economy (ecotourism)
Specialist
An organism with very specific requirements; whether it be food source, shelter, reproduction, etc. more affected by disturbances (ex. Panda)
Generalists
An organism with broad tolerances, able to use a wide variety of resources; less affected by disturbances (ex. raccoon)
