Evidence of EVOLUTION

Evidence Supporting Evolutionary Theory Fossil Record Fossil Record Biogeography Biogeography Homologies Homologies Anatomical- Homologous structures Anatomical- Homologous structures Anatomical- Vestigial structures Anatomical- Vestigial structures Molecular- DNA Similarities in the genetic code Molecular- DNA Similarities in the genetic code Developmental- Embryology Developmental- Embryology

Fossils Remains, impression, tracks or other evidence of an organism that lived long ago Most fossils are found in layered sedimentary rock. Newest fossils are at the top. Oldest fossils are at the bottom. Ancient shrimp fossil A shrimp today

Biogeography Scientists can study the distribution of species to help them determine evolutionary relationships. Scientists can study the distribution of species to help them determine evolutionary relationships. Species that evolved from a common ancestor are usually found geographically near each other. Species that evolved from a common ancestor are usually found geographically near each other. Just because two ecosystems are very similar, it doesn’t mean you will find the same species inhabiting it. Just because two ecosystems are very similar, it doesn’t mean you will find the same species inhabiting it. Patterns in the diversity and distribution of species. The continental drift theory, first proposed by Alfred Wegener in 1912, has been supported by oceanographic evidence. Continental drift has also influenced the distribution of species. What is it? Why aren’t they found in both places? Why are there penguins found in Australia, Chile, and South Africa?

Homologous structures Structures that share a common ancestor may have the same anatomical structure but may have adapted in ways that enable the organism to survive in different environments. Anatomical Homologies

Anatomical similarities Turtle Alligator Bird Mammal Some organisms may not look alike, but they’re built alike Homologous structures show evidence of: - similar genes -common ancestor

Homologous Structures Turtle Alligator Bird Horse common ancestor

Vestigial Structures Body parts and organs that are reduced (smaller) in size and have no benefit, but are still present in the body. Body parts and organs that are reduced (smaller) in size and have no benefit, but are still present in the body. Ostrich with wings Blind cave salamander and blind cave fish

Pelvis in Snakes without legs

DNA The genetic material of some organisms is very similar. The genetic material of some organisms is very similar. DNA sequences that are very similar tell us the organisms originate from a common ancestor. DNA sequences that are very similar tell us the organisms originate from a common ancestor. When they are very different, we know the organisms are not related. When they are very different, we know the organisms are not related. Amino acids are coded by DNA. Amino acids are coded by DNA. Amino Acid Difference in Hemoglobin Compared with Human

Animal Amino Acid Sequences in Cytochrome-C Horse glnprophethr alalysasnlysthrlysglu thrleumetglulysalathr Shark gln pheserthrasplysserlysthrgln gluthrleuargilelysthrala Human glnprotyrserthralalysasnlysileglygluaspthrleumetglulysalathr Turtle glnglupheserthrglulysasnlysthrglygluaspthrleumetgluaspalathr Monkey glnprotyrserthralalysasnlysthrglygluaspthrleumetglulysalathr The chart below shows the amino acid sequence for cytochrome-c of five vertebrates. 1. Compare the amino acid sequence of human cytochrome-c with that of the other four vertebrates.

DNA Hemoglobin Comparison Amino acid differences from HUMAN hemoglobin protein Species Lamprey eel125 Frog Chicken Gorilla Mouse Rhesus monkey DNA directs the assembly of amino acids into specific proteins; therefore, species that shared a common ancestor more recently have fewer amino acid differences.

Embryology The similarities between the development and growth of a fertilized egg cell. Embryos of different species may appear similar in early stages of development Bird embryoHuman embryo

Embryo Development click here