Classifying Organisms

The three main reasons scientists classify organisms is to be able to identify them, predict their characteristics and identify evolutionary links.If several species of a genus have a particular characteristic, it is likely that other species in the genus have the same characteristic.Species of the same group probably evolved from a theoretical common ancestor.By using a common classification system scientists all over the world can share research.There are three domains: Archaea, Bacteria and Eukarya at the top of the hierarchy.The smallest group is a species: a group of organisms that can interbreed to form fertile offspring. Phylogenetic classification is based on evolutionary relationships between organisms and their ancestors and homologous characteristics which have similar genetic origins.Homologous characteristics have similar genetic origins but may appear differentAnalogous characteristics have the same function but do not have the same evolutionary origins.