Presentation on theme: "Many types of evidence support evolution"— Presentation transcript:
1Many types of evidence support evolution Note for B 1.3Many types of evidence support evolution
2Observations provide evidence for theories. Theory—a widely accepted statement based on scientific evidence that helps explain and predict natural phenomenaTheory of Evolution—based on three sources of evidence:FossilBiologicalgenetic
3Fossil evidence supports evolution. Fossil evidence shows that 2 speciees with a common ancestor can develop differently.Ancestor—a distant or early form of an organism from which later forms descend
4Biological evidence supports evolution. Includes the structure and development of living thingsIncludes vestigial organs and similar structures with different functionsVestigial organs—physical structures that are longer useful to a living organism, but may have existed as fully developed similar structures useful to a common ancestor (vestigial limb in a whale)
5Biological evidence (continued) Different species share many similar structures, but these have different functions, such as the forelimbs of a bat, gecko, lizard, or manatee.Similarities is embryonic development also indicate common ancestry.
6Genetic development supports evolution. Similar organisms have very similar genes; less closely related organisms have genes that are easy to tell apart.Organisms with similar patterns of DNA also share common ancestors.