Biology 1001A Chapter Notes - Chapter Chapter 9 : Convergent Evolution, Mosaic Evolution, Evolutionary Taxonomy
19 Dec 2017
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Document Summary
Phylogenies show the evolutionary history of a group of organisms. Phylogenies are presented as phylogenetic trees, which are formal hypotheses identifying likely relationships among groups of organisms. What types of traits are useful in determining evolutionary relationships: along with morphology, they considered patterns of behaviour and traits such as chromosomal anatomy, details of physiology, morphology of subcellular structures, cells, and organ systems. Modern systematists also use molecular sequences of nucleic acids and proteins as additional characters: seek characters that are independent markers of underlying genetic similarity and differentiation, rely on phenotypic traits as indicators of genetic similarity or divergence. Meanings of mosaic evolution, ancestral character, derived character. Mosaic evolution: the reality that in all evolutionary lineages, some characters evolve slowly, while others evolve rapidly. Every species displays a mixture of ancestral characters (old forms of traits) and derived characters (new forms of traits) Whether ancestral or derived characters are more useful in determining evolutionary relationships.
