Chapter 25 Phylogeny- evolutionary history of a species or group of species Systematic- understanding diversity and relationships of both present-day and extinct organisms; analyzes morphological and biochemical diff Molecular Systematics- compares DNA, RNA and other molecules to infer evolutionary relationships btwn individual gens or entire genomes Morphology + Biochemistry + Fossil Record Phylogenies Fossil Record- based on sequence in which fossils have accumulated in strata; sedimentary rocks strata (higher %) organisms preserved a. Incomplete chronicle of evolutionary change due to impossible preservation of all organisms that are now extinct b. Biased of how species that are found as fossils have features that allow allowed preservation wrong; just right place/timing Homologies- similarities due to shared ancestry (i.e. same number and arrangement of bones in forelimbs of mammals; DNA seq/genes) Morphologies- physical similarities distinguishing similar organisms (i.e. Hawaiian plants, however, look different but have similar DNA seq) Analogies- similarities due to convergent evolution (i.e. wings of bats, birds and moths) Convergent Evolution- similar environment selects to produce similar (analogous) adaptations in organisms of different ancestry Homoplasies- analogous structures that have evolved
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This note was uploaded on 08/27/2010 for the course BIO 8432 taught by Professor Lang during the Spring '10 term at Northwestern IA.