PHYLOGENY AND THE TREE OF LIFE

 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. PHYLOGENY

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

 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 LEVELS OF HIERARCHAL CLASSIFICATION

 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) THE LINK BETWEEN CLASSIFYING AND PHYLOGENY

 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) COMMON TERMS

 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 APPLYING PHYLOGENETICS