Bell ringer 102214 What is the difference between

Bell ringer- 10/22/14 What is the difference between relative age dating and absolute age dating? Regents Biology

Evidence supporting evolution § Fossil record u shows change over time § Anatomical record u comparing body structures § homology & vestigial structures § embryology & development Regents Biology

3. Comparative Anatomy Animals with different structures on the surface But when you look under the skin… It tells an evolutionary story of common ancestors Regents Biology

Compare the bones § The same bones under the skin u limbs that perform different functions are built from the same bones How could these very different animals have the same bones? Regents Biology

Homologous structures § Structures that come from the same origin § homo- = same § -logous = information § Forelimbs of human, cats, whales, & bats u same structure § on the inside same development in embryo u different functions u § on the outside u Regents Biology evidence of common ancestor

Comparative Anatomy Regents Biology

But don’t be fooled by these… § Analogous structures u look similar § on the outside same function u different structure & development u How is a bird like a bug? § on the inside different origin u no evolutionary relationship u Regents Biology Solving a similar problem with a similar solution

Analogous structures § Dolphins: aquatic mammal § Fish: aquatic vertebrate both adapted to life in the sea u not closely related u Watch the tail! Regents Biology

OTHER EVIDENCE OF EVOLUTION VESTIGIAL STRUCTURE EMBRYOS

Vestigial Structures Regents Biology

Vestigial Structures § Hind leg bones on whale fossils Why would whales have pelvis & leg bones if they were always sea creatures? Because they used to walk on land! Regents Biology

Comparative embryology § Development of embryo tells an evolutionary story u similar structures during development all vertebrate embryos have a “gill pouch” at one stage of development Regents Biology

Comparative Embryology Regents Biology

OTHER EVIDENCE OF EVOLUTION • FOSSILS • ANATOMY – HOMOLOGOUS STRUCTURES – ANALOGOUS STRUCTURES – VESTIGIAL STRUCTURE – EMBRYOS • BIOCHEMISTRY – WHAT 2 THINGS? http: //evolution. berkeley. edu/evolibrary/home. php Life Sciences-HHMI Outreach. Copyright 2006 President and Fellows of Harvard College.

Cladogram- Relationships among organisms