AP bio Unit 7

Evolution

Change in the genetic makeup of a population overtime

Natural Selection

Process by which organisms better suited to an environment have a higher chance of survival to reproduce

Variation

Genetic differences among organisms in a population

Adaptation

Factors that provides advantages in an environment

How do we measure evolutionary fitness?

By reproductive success

Fitness

The ability of an organism to survive and produce fertile offspring

Reproductive success

Production of offspring

Heritability

The ability to pass on traits

How does environmental stability affect evolution?

• More stable environments have populations that are less likely to evolve

• The more unstable an environment is, the quicker the evolution is

Why is genetic/phenotypic variation important to a population?

• Genetic variation increases the probability a population will survive in a changing environment

  • Genetic variation can result in varying phenotypes →higher chance of one being better suited

Genetic variation

Genotypic and Phenotypic differences between individuals in a population

Selective pressure

Any biotic or abiotic factors influencing survivability

How do phenotypes affect fitness?

Phenotypes that increase an individuals chances of survival will increase fitness

Artificial selection

The process by which humans select desirable traits in organisms and selectively breed those traits.

What can artificial selection result in?

• Phenotypes that wouldn’t exist in nature otherwise

• More OR less genetic diversity

Convergent evolution

The process by which similar environmental conditions select for similar traits in different populations/species overtime

Analagous structures

Similar traits observed in distantly related or unrelated species