Many types of evidence support evolution Note for B 1.3 Many types of evidence support evolution

Observations provide evidence for theories. Theory—a widely accepted statement based on scientific evidence that helps explain and predict natural phenomena Theory of Evolution—based on three sources of evidence: Fossil Biological genetic

Fossil 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

Biological evidence supports evolution. Includes the structure and development of living things Includes vestigial organs and similar structures with different functions Vestigial 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)

Biological 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.

Genetic 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.