Presentation on theme: "1. Biogeography-study of distribution of organisms around the world."— Presentation transcript:
1 KEY CONCEPT Evidence of common ancestry among species comes from many sources.
2 1. Biogeography-study of distribution of organisms around the world. island species most closely resemble nearest mainland speciespopulations can show variation from one island to another
3 Evidences for evolution 2. Fossils—traces of organisms from the pastFossils in older layers are more primitive than those in the upper layers.
4 Paleontology provides evidence to support evolution.
5 3. Embryology: The study of the developing embryo. Different organisms go through similar stages in the developing embryo*Gill slits*Tails
6 3. Embryology-study of embryos and their development. identical larvae, different adult body formssimilar embryos, diverse organismsLarvaAdult barnacleAdult crab
7 4. Anatomy-study of body structures A. Homologous structures are similar in structure but may be different in function.Homologous structures are evidence of a common ancestor.Human handBat wingMole foot
8 Analogous structures are not evidence of a common ancestor. B. Analogous structures have a similar function but not similar origin.Human handBat wingMole footFly wingAnalogous structures are not evidence of a common ancestor.
9 C. Vestigial structures are remnants of organs or structures that no longer serve a purpose. Ostrich wings are examples of vestigial structures.
11 In humans:Wisdom teethEar musclesTail boneNictitating membrane
12 Biochemical Similarities 5. Molecular Similarities-Two closely-related organisms will have similar DNA sequences, proteins, etc.
13 *Hox genes indicate a very distant common ancestor. Genetic Similarities- certain genes are found in many organisms, from fruit flies to humans*Hox genes indicate a very distant common ancestor.*control the development of specific structures