Phylogeny and the tree of Life

Phylogeny Phylogeny is the evolutionary history of a species or a group of species. To determine how an organism is classified, we use systematics, which is a system of classifying organisms and determining their evolutionary relationships.

Binomial Nomenclature Binomial Nomenclature is a system of naming organisms based on evolutionary relationships with other known species.

Levels of hierarchal classification At any level, a level of classification is called a taxon. The levels of classification are from most general to most specific: Domain Kingdom Phylum (division in plants) Class Order Family Genus Species

The link between classifying and phylogeny Classifying is good at distinguishing groups that have similar properties, however it doesn’t link the evolutionary relationships between the various groups. When we want to link the various groups of organisms to each other, we use a phylogenetic tree. (figure 26.4)

Common terms Sister taxa: groups that share an immediate common ancestor. Rooted tree: tree shows the latest common ancestor that all organisms in the tree share. Basal taxon: group that diverges early in the tree. Polytomy: more an two groups emerge from a single divergence. (>2)

Applying Phylogenetics We can use phylogenetics to determine closest living relatives to modern species to allow for the hybridization of two species through the process of genetic engineering. Figure 26.6 Minke Whale