BIOL 005B Lecture Notes - Lecture 1: Carl Linnaeus, Binomial Nomenclature, Ingroups And Outgroups
Document Summary
Biol 005b lecture 1: tree of life, phylogeny. Phylogeny is the evolutionary history of a species or group of related species. The discipline of systematics classifies organisms and determines their evolutionary relationships. In the 18th century, carolus linnaeus published a system of taxonomy based on resemblances. Two key features of his system remain useful today: Systematists depict evolutionary relationships in branching phylogenetic trees. A phylogenetic tree represents a hypothesis about evolutionary relationships. Each branch point represents the divergence of two species. Sister taxa are groups that share an immediate common ancestor. To infer phylogenies, systematists gather information about morphologies, genes, How is a phylogeny constructed? and biochemistry of living organisms. Organisms with similar morphologies or dna sequences are likely to be more closely related than organisms with different structures or sequences. Homology is similarity due to shared ancestry. Analogy is similarity due to convergent evolution.
