BIOA01H3 Lecture Notes - Lecture 9: Cyanobacteria, Carl Linnaeus, Liger

• School: UTSC
• Department: Biological Sciences
• Course: BIOA01H3
• Professor: Mark Fitzpatrick

Document Summary

Biologists classify life on earth using a hierarchical classification system: domain, phylum, class, order, It is important to select characters that are homologous (shared) evolutionary history and be careful about homoplasies (analogies) or traits that have evolved from convergent evolution. Branching patterns that are monophyletic, polyphyletic and paraphyletic. They analyze morphological/genetic characteristics to infer phylogenetic relationships among species. General strategies to estimate trees is the phenetic cladistics approach. Phenetic approach is based on computing a statistic that summarizes the overall similarity among populations and starts to group them together based on most similar and keeping most diverged branches at a distant. Synapomorphies which is the shared derived characters of the species under study. When many traits are measured, traits unique to each monophyletic group are identified and the groups are placed on a tree in the appropriate relationship to one another. Making trees are not easy, they are complex.