Presentation on theme: "Evidence for evolution in Darwin’s time came from several sources."— Presentation transcript:
1 KEY CONCEPT Evidence of common ancestry among species comes from many sources.
2 Evidence for evolution in Darwin’s time came from several sources. FossilsGeographyEmbryologyMolecular BiologyAnatomy
3 FossilsFossils – preserved remains or markings left by organisms that lived in the pastFossils provide evidence of evolution.Fossils in older layers are more primitive than those in the upper layers.
4 FossilsFossil record – the chronological collection of life’s remains in sedimentary rock layers.
5 Transitional forms are links between modern animals and ancient. Mesonychilds are thehypothesized linkbetween modernwhales and hoofedmammals.
6 GeographyThe study of geography provides evidence of evolution.Island species closely resemble nearest mainland speciesPopulations show variation from one island to anotherDifferent plants, climates, and predators favored different traits in the population
7 Embryology provides evidence of evolution. Identical larvae, different adult body formsSimilar embryos, diverse organismsLarvaAdult barnacleAdult crab
8 EmbryologyEmbryology provides evidence of evolution.Embryos of fish, birds, reptiles, and mammals are all similarThey all have gill slits which develop into gills in adult fish and ears and throat in mammalsMolecular BiologyDNA and protein sequences are similar between related organisms
9 AnatomyThe study of anatomy provides evidence of evolution.Homologous structures are similar in structure but different in function.Homologous structures are evidence of a common ancestor.
10 The study of anatomy provides evidence of evolution. Analogous structures have a similar function.Analogous structures are not evidence of a common ancestor.These species evolved separatelyThey faced similar environmental challenges and developed similar solutionsHuman handBat wingMole footFly wing
11 Vestigial structures are remnants of organs or structures that had a function in an early ancestor. Ostrich wings are examples of vestigial structures.Examples in humans- appendix and coccyx (tail bone)