Evidence of Evolution

Hello you started biology 2 (yippie) good luck studying !

Evolution

Descent with modification results in diversity of life (shared ancestry accumulates differences)

Adaptations

Inherited characteristics of organisms that enhance fitness in specific environments

Natural Selection

Process by which organisms with favorable traits are more likely to survive and reproduce

Fitness

Ability to survive

What does natural selection not do?

Does not guess what will help an organism survive

Lamarck's theory of evolution

Variation is acquired in a lifetime (giraffe having a stretched neck thus offspring have slightly longer “stretched” neck)

Darwin’s theory of evolution

Inherited variation (giraffe’s happened to be born with longer necks, survived, and passed that gene to offspring)

For natural selection to work you need:

• Variation that is present in population

• Variation must influence fitness (survivability)

• Must be inherited/inheritable

Artificial Selection

Process by which humans modify organisms by selecting and breeding organisms for certain traits

Pleiotropy

One gene codes for multiple traits