Evidence for Evolution 1 Fossil Record Age Behavior

Evidence for Evolution

1. Fossil Record Age & Behavior patterns Show changes in climate & geography

1. Fossil Record

1. Fossil Record Shows evolution & adaptation Problems: Incomplete fossils & Imperfectly preserved

Fossil Record Similar Fossils in multiple layers Fossils that disappear

What similarities do you see among the forelimbs of these animals?

2. Homologous structures – similar internal structure found in different groups of organisms

2. Homologous structures May or may NOT look the same on the outside May have a different function Shows common ancestor Ex. forelimbs of vertebrates

What is a similar feature of these 2 organisms?

3. Analogous Structures w/similar function, but different internal structure

Shows evolution But NOT by a common ancestor Ex: wings – bats, insects, & birds

4. Vestigial Structures/organs that are no longer used May have been used by ancestor Indicate a change has occurred

Examples Ostrich wings Human appendix Cave fish eyes

5. Embryology Many different animals have the same organs when they are embryos Ex: embryos of fish, reptiles, birds & mammals all have gills. Suggests evolution from a common ancestor zebrafish chicken dog human skunk

Evidence for Evolution 1) Fossil Record 2) Homologous Structures 3) Analogous Structures 4) Vestigial Structures 5) Embryology

Evidence for Evolution Lab

Evidence for Evolution 1) Fossil Record 2) Homologous Structures 3) Analogous Structures 4) Vestigial Structures 5) Embryology

6. Genetic Comparisons Shows evolutionary relationships using DNA sequences Ex. DNA sequence for ATP is the same for all living organisms Ex. Homologous structures require similar DNA

Which 2 species are most similar? Least similar?

A B C Which 2 insects are most closely related? Most distantly related? D

Evolutionary Diagrams Phylogenic trees and Cladograms – Diagrams that shows evolutionary relationships of organisms based on similarities and differences in their physical or genetic characteristics.

Common Ancestor