GE CLST 70B Lecture Notes - Lecture 4: Egg Incubation, Tetrapod, Echidna
23 Jan 2017
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Tree branches can split, break off, or stop growing. Edward hitchcock: american geologist, made an early and very inaccurate evolutionary tree. Taxonomy: classifying organisms into hierarchical groups based on similarities: domain, kingdom, phylum, class, order, family, genus, species, li(cid:374)(cid:374)aeus (cid:272)a(cid:373)e up (cid:449)ith this syste(cid:373) i(cid:374) the (cid:1005)7(cid:1004)(cid:1004)s a(cid:374)d it"s (cid:271)ee(cid:374) used e(cid:448)er si(cid:374)(cid:272)e. Phylogenetics: illustrating evolutionary relationships by constructing phylogenetic trees based on characteristics of extant taxa: extant = in existence, not extinct. Systematics: using evolutionary relationships to group organisms into hierarchical groups. Taxonomy (classification) + phylogenetics (evolutionary patterns) = systematics. Phylogeny: true evolutionary history of a group of organisms. Phylogenetic tree: hypothesis of evolutionary relationships based on genetically determined traits: morphology, physiology, development, molecules (dna and amino acids) Clade/monophyletic group: an ancestor + all of its descendants. Species on a phylogenetic tree are more closely related to species they share a recent common ancestor with. Branches can be rotated around nodes without changing the topology of the tree.
