BIOA01H3 Lecture Notes - Lecture 32: Carl Linnaeus, Ecological Niche, Parthenogenesis

• School: UTSC
• Department: Biological Sciences
• Course: BIOA01H3
• Professor: Steve Joordens

Document Summary

Biologists classify ever organism (like sorting toys) Biologists classify life on earth using a hierarchical classification system: domain, kingdom, phylum, class, order, family, genus, species. Selection of characters upon which to base your classifications is important (homology vs. homoplasy) Monophyletic can be traced back to a single common ancestor. Polyphyletic includes species from different evolutionary lineages. Paraphyletic includes an ancestral species and only some of its descendants. Cladogram looks at relation between taxa in question; branch lengths are not important. Phylogeny take time into account, sometimes show extinct species; asks questions of the degree of relatedness between taxa; branch lengths are important because they tell us the time and amount of divergence. When building a phylogeny start with an unrooted tree. Thankfully, computer software often does this for us. A tree with 60 taxa would not be considered large by today"s standards. Dna, rna and amino acid changes reflect evolution.