BIOL2010 Study Guide - Midterm Guide: Cambrian Explosion, Phanerozoic, Evolutionary Arms Race
Document Summary
Evolution and history of life: advances in evolutionary theory the earth is much older than people originally though, species change over time. Documented through fossils: helped create homology. Similar structure between species inherited from a common ancestor: a single phylogeny can be hypothesized to show relationships among all species. Eukarya: most of the species that have ever lived are extinct. Constructing phylogenies: need to collect data on features and traits (characters) Sequence of dna: taxa have different versions of characters and different versions are character states, characters states can be classified as. Trait found in 2 or more taxa and their common ancestor but missing in more distantly related ancestors. Example: orangutan, gorilla, human all have no tail (synapomorphy) Provides one bit of evidence that species are all each other"s closest relatives. Changes tree until the number of changes is low. The smaller the number of changes the more favorable the tree.
