Biology 1001A Lecture Notes - Lecture 19: Ingroups And Outgroups, Autapomorphy, Symplesiomorphy
22 Nov 2016
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Document Summary
Phylogeny: evolutionary history of a group of organisms. Presented as phylogenetic trees (branching diagram depicting the evolutionary relationships of groups of organisms) Are formal hypotheses of relationships/relatedness between species. Before linnaeus, phylogenies were classified based on morphological characteristics. Over time more traits were being used to determine evolutionary relationships. Patterns of behavior, chromosomal anatomy, details of physiology, morphology of subcellular structures, cells, and organ systems. Homologous, analogous, ancestral, and derived characters indicate evolutionary relationships between different organisms. Some phylogenetic trees show relatedness of large groups of organisms (phyla or classes); others show how genera or species are related. Many phylogenies include prehistoric organisms along with modern-day ones. Meanings of mosaic evolution, ancestral character, derived character. Mosaic evolution: tendency of characteristics to undergo different rates of evolutionary change within the same lineage it"s per(cid:448)asi(cid:448)e. Some characteristics evolve slowly while others evolve more rapidly. Ancestral characters: characters that are present in distant common ancestors.
