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 significantly differentiate from an ancestral population, a new species name may be assigned. A key point is that the entire population is different from the ancestral population such that the ancestral population can be considered extinct. It is easy to see from the preceding definition how controversy can arise among taxonomists when the differences are significant enough to warrant a new species classification. Anagenesis may also be referred to as "gradual evolution".
Bibliography
- Korotayev, Andrey (2004). World Religions and Social Evolution of the Old World Oikumene Civilizations: A Cross-cultural Perspective, First Edition, Lewiston, New York: Edwin Mellen Press. ISBN 0-7734-6310-0. (on the applicability of this notion to the study of social evolution).
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| Evidence of evolution | |
| Processes of evolution | Adaptation · Macroevolution · Microevolution · Speciation |
| Population genetic mechanisms | Natural selection · Genetic drift · Gene flow · Mutation |
| Evolutionary developmental biology (Evo-devo) concepts |
Phenotypic plasticity · Canalisation · Modularity |
| Modes of evolution | Anagenesis · Catagenesis · Cladogenesis |
| History | History of evolutionary thought · Charles Darwin · On the Origin of Species · Modern evolutionary synthesis · Evolutionary history of life · Life (classification trees) |
| Other subfields | Ecological genetics · Human evolution · Molecular evolution · Phylogenetics · Systematics |
| List of evolutionary biology topics · Timeline of evolution | |
