Most evolution consists of two processes: anagenesis and cladogenesis. Anagenesis describes the transformations occurring within a single lineage, as a population develops new characteristics. Cladogenesis, by contrast, describes the splitting of a...

Anagenesis, also known as "phyletic change", is the evolution of species involving a change in gene frequency in an entire population rather than a branching event, as in cladogenesis. When enough mutations reach fixation in a population to...