The evidence for evolution - Lecture 3

4 sources of evolution

1. Geology

2. Homology

3. Biogeography

4. Domestication

Vestigial structure

Features from a common ancestor that isn’t functional anymore

EX. Appendix

Homology

Similarities of traits from a common ancestor

3 Major themes of biogeography

1. Geographically close organisms resemble each other

2. Different organisms adapt to similar environments around the world

3. Geographically isolated regions have weird Organisms

Endemic Radiation VS Convergent Evolution

Endemic - 

One original species arrives in a new area → spreads out → evolves into many different species, each adapted to different niches (galapagos)

Convergent - 

Different, unrelated species evolve similar traits because they live in similar environments or face similar pressures.

Evidence From Domestication (2)

Artificial Selection -

We can select for desired traits

There’s a lot of heritable variation

What does geology teach us about Earth that supports evolution?

Earth is very old, which gives enough time for biological evolution to occur.

What are transitional fossils?

Fossils that show intermediate forms linking seemingly different groups (e.g., whales and ungulates, fish and tetrapods).