Evidence for

Evolution

Evidence for Evolution

•Homology•Convergent evolution•Vestigial structures•Embryology•Fossils•DNA

Homology– Evidence of a Common Ancestor

Homology– Evidence of a Common Ancestor

•When we see very similar parts in many living things, we gain evidence of their common ancestor and its characteristics.

Convergent Evolution

Convergent Evolution

Convergent Evolution

Convergent Evolution

Convergent Evolution

•Most evolution is Divergent (species with similar traits have a common ancestor)

•According to Natural Selection, species evolve traits that help them survive in an environment.

•Sometimes, the requirements to survive in an environment are so strong that several VERY DIFFERENT SPECIES evolve traits that function in similar ways. This is convergent evolution.

Vestigial Structures

Vestigial Structures

Vestigial Structures

Vestigial Structures

Vestigial Structures

Vestigial Structures

•Structures that are no longer useful, such as our appendix,, or the fingers on a whale are vestigial structures. They are evidence that these creatures evolved from other creatures that used these structures.

Embryology

Embryology

Embryology

•Embryos of some animals show traits that are not present in adults such as gills and tails in humans. These are evidence that these traits were found in our ancestors.

Fossils

Fossils

Fossils

Fossils

Fossils

Fossils

•There are fossils of many creatures that no longer exist today. They often show missing links between species that exist today and their ancestors.

•We also see that fossils deeper in the earth only show simpler creatures with more advanced life forms closer to the surface.

DNA Similarities

DNA Similarities

If you look at the DNA of living creatures you can see the similarities.

Many sections of DNA are don’t code foe anything at all. These sections are similar to working or useful sections in other creatures.

Even in human DNA, you can see the broken parts of code that were important in an organism long ago