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Pages 126 - 133. Developing a Theory to Explain Change: E vidence for Evolution. Evidence of Evolution . 1. The fossil record 2. Transitional fossils 3. Patterns of distribution 4. Anatomy 5. Embryology 6. Molecular biology 7. Genetics. 1. THE FOSSIL RECORD :.
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Pages 126 - 133 Developing a Theory to Explain Change: Evidence for Evolution
Evidence of Evolution • 1. The fossil record • 2. Transitional fossils • 3. Patterns of distribution • 4. Anatomy • 5. Embryology • 6. Molecular biology • 7. Genetics
1. THE FOSSIL RECORD : • Paleontology: study of fossils; remains of once living organisms. • Fossils found in young layers of rock are more similar to present day species than fossils in older layers of rock • Fossils appear in chronological order, ancestral species found in layers beneath • Not all species appear in the record at the same time
2 - Transitional Fossils • The original fossil record gave “scattered snapshots” of ancestral forms • On-going discoveries of hundreds of transitional fossils show intermediate links
3 - Biogeography • Biogeography: the study of past and present geographical distribution of organisms. • Darwin and Wallace hypothesized that organisms evolve in one location and then spread out to other regions.
4 - Comparative Anatomy • Homologous structures: • similar structure and evolutionary origin • may have different function • Analogous structures: • similar functions • do not have common evolutionary origin Reverse Engineering the Chicken
5 - Embryology • Embryonic development of many organisms shows uniformities • Embryonic similarities are particularly obvious during early stages of development
6 - Molecular Biology: • The field of molecular biology has developed as technologies to identify molecules, such as DNA and protein molecules, has developed. • If two species have similar patterns in proteins of their DNA, this similarity indicates that these portions of their DNA were most likely inherited from a recent common ancestor
7 - Genetics • The use of modern technologies has led to many discoveries that support Darwin’s theory. • The field of genetics has lead to understanding of how species pass on their traits to their offspring and how the blueprints for these traits can change by mutation.
Homework • On the slip of paper provided, create one test/quiz question from the information you learned today. • Homework for Tomorrow: • Section 4.2 Questions • #1,2,3,6,7,8,10