Evidence of Evolution Original presentation courtesy of Mrs. Jennifer Boyd, WHS

Overview: I. Anatomical Evidence II. Embryological Structures III. Molecular Evidence IV. Paleontology

I. Anatomical Evidence A. Homologous structures : features in different species that are from a shared ancestor. Features can look similar but function differently from each other. Features come from similar structures in the embryo.

B. Vestigial structures: reduced forms of functional structures in other organisms. 1. Vestigial structures give clues to ancestors. 2. Examples:  Wisdom teeth  Snake’s pelvis- no legs on a snake for pelvis to attach to  Whale pelvis  Wings on a kiwi- too small for flight I. Anatomical Evidence

II. Embryological Structures A. Embryology: study of the development of living organisms. Embryo: early, pre-birth stage of an organism’s development B. The development of vertebrate embryos is similar in the early stages This similarity may be an indication of a common ancestor

Yolk sac II. Embryological Structures

A. Similarities at the molecular level: Similar proteins RNA DNA B. The more similar these molecules are, the more closely related the organisms are. III. Molecular Biology: Biochemistry

QUICK CHECK!  DNA codes for __RNA which is used to make ______________.  Proteins are made up of _____________.  What organelle makes proteins?

E. Proteins Human hemoglobin and gorilla hemoglobin differ in their protein sequence by one amino acid. Frog hemoglobin differs by 67 amino acids. → So which is more closely related to a humans based on amino acid sequence? III. Molecular Biology: Biochemistry

IV. Paleontology: Biogeography A. Biogeography: study of the geographical distribution of fossils and of living organisms B. From looking at the fossils, these scientists found that recent fossils look similar to organisms currently living in the area. → What does this suggest?

IV. Paleontology: Biogeography

A. Fish to amphibians: Tiktaalik roseae Mix of fish and amphibian traits Scales, fins, lungs, gills Flat head, fin skeleton IV. Paleontology: Transitional Forms

C. Archaeopteryx Feathers, opposable big toe IV. Paleontology: Transitional Forms