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Evidence of Evolution Learning Objectives ▪ Describe how the geologic distribution of today relates to their evolutionary history. ▪ Identify how help document the descent of modern species. ▪ Explain what homologous structures and similarities in development suggest about the process of evolutionary change. ▪ Describe how molecular biology can be used to trace the process of evolution. ▪ Explain what recent research of the Galápagos finches show about natural selection.

Biogeography Evidence From Fossils Patterns in the distribution of fossils and living species, could combined with information from geology, tell us how modern both swim in shallow water and walk on land. probably spent organisms evolved from their ancestors. most of its time in water.

Ambulocetus Rodhocetus Ancient artiodactyl

Evidence of Evolution Homologous Structures

Modern have • Similar structures that are shared by related ancient structures species and have been inherited from an common ancestor Odontocetes

Basilosaurus Mysticetes only swims.

Modern whales

Dorudon

Basilosaurus

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Homologous Structures Vestigial Structures

Homologous structures inherited from ancestors, but have lost much of their original size and function

Examples: ear wiggling muscles, pelvic and thigh in cobras and whales

Vestigial Structures Analogous structures • Body parts that serve similar function, but do not share structure and development • Unrelated species • Examples: • Bat wings and bird wings • Cacti and euphorbia

Embryology and Development Genetics and Molecular Biology Similar patterns of embryological development provide At the molecular level, overwhelming similarities in the further evidence that organisms have descended from a genetic code of all organisms, along with homologous genes common ancestor. and molecules, provide evidence of common descent. •All living cells use information coded in DNA and RNA to carry information from one generation to the next and to direct protein synthesis •Genetic code is nearly identical in almost all organisms

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Testing Natural Selection

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