Phylogeny (Gr. Phylon = tribe or race; geneia = origin) is the origin and diversification of any taxon or the evolutionary history of its origin and diversification. It is usually represented as a diagrammatic phylogenetic tree (that traces putative evolutionary relationships) i.e., dendrogram. Palaentology is the study of fossils. Ontogeny is the whole course of an individual's development and life history.