One of the two major branches of biology (the other being functional biology) that covers a vast array of subject matter associated with a number of different sub-fields. The main topics covered can be conveniently accounted for under the headings of ‘phylogeny’ and ‘biological evolution’. Phylogeny: determining ancestor-descendant relationships among all species, their times of origin and extinction, and the rate (gradual or abrupt) and course of change in their characters. Biological evolution: aims to understand the origins of hereditary variations, what are the levels and units of natural selection, how and under what conditions the purported mechanisms of evolutionary change such as mutation, natural selection, sexual selection, genetic drift and genetic recombination operate and give rise to adaptations, the relative importance of these co-acting mechanisms, how populations become different species (i.e., the process of speciation), the interrelationships between biological and cultural evolution, and those between ontogenetic development and biological evolution. Sub-fields include, for example: palaeontology, systematics, population genetics, molecular evolution, and more recently evolutionary developmental biology.
See Adaptation, Biological evolution, Biology, Character, Cultural evolution, Cultural evolution and biological evolution, Developmental biology, Evolutionary developmental biology, General theory of biological classification, Genetic drift (or random walk), Genetic (or DNA) recombination, Lumping ( or splitting), Macroevolution (horizontal evolution) and microevolution (or vertical evolution), Mutation (biology), Natural selection, Ontogenetic development, Ontogeny, Palaeontology, Phylogeny, Population genetics, Species, Speciation, Theories of molecular evolution, Theory of natural selection, Theory of sexual selection