Honors Biology - Unit 8 - Evolution

What is the importance of geologic history?

It shows that the earth is very old

What is the importance of the fossil record?

It provides evidence of organisms that were ancestors of living organisms

Why do gaps in the fossil record occur?

Geologic processes destroy fossils and some organisms don't fossilize well

What provides biochemical evidence for evolution?

Differences in DNA and proteins

What is the importance of homologous structures?

They have the same genetic origin, meaning that the genes are nearly identical in many different organisms, but end up having different phenotypes depending on the purpose

What is a vestigial structure?

An evolutionary leftover which once served a purpose and over time becomes smaller and less necessary. The genes are still present but are barely used, so only vestiges of the structure form. Changes like the smaller pelvis and legs in whales and snakes cannot be passed down genetically because it occurs randomly

What was Charles Darwin's contribution to our understanding of evolution?

The idea of evolution through natural selection, or survival of the fittest and that the starting point for evolution is variation.

What is descent with modification?

The idea that all organisms we see on Earth descend from a common ancestor. The more similarities you have, the more recent your common ancestor is.