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Speciation is the evolutionary process by which populations evolve to become distinct species.The biologist Orator F. Cook coined the term in 1906 for cladogenesis, the splitting of lineages, as opposed to anagenesis, phyletic evolution within lineages.
Controversy exists as to whether Charles Darwin recognized a true geographical-based model of speciation in his publication On the Origin of Species. [5] In chapter 11, "Geographical Distribution", Darwin discusses geographic barriers to migration, stating for example that "barriers of any kind, or obstacles to free migration, are related in a close and important manner to the differences ...
Scientists now have a good understanding of the origin of new species and have observed the speciation process in the laboratory and in the wild. Evolution is the principal scientific theory that biologists use to understand life and is used in many disciplines, including medicine , psychology , conservation biology , anthropology , forensics ...
Parapatric speciation – Speciation within a population where subpopulations are reproductively isolated; Sympatric speciation – Evolution of a new species from an ancestor in the same location; Artificial speciation Animal husbandry – Management of farm animals; Plant breeding – Humans changing traits, ornamental/crops
A speciation event produces orthologs in the two daughter species (human and chimpanzee). Bottom: in a separate species ( E. coli ), a gene has a similar function ( histone-like nucleoid-structuring protein ) but has a separate evolutionary origin and so is an analog .
Population genetics is a subfield of genetics that deals with genetic differences within and among populations, and is a part of evolutionary biology.Studies in this branch of biology examine such phenomena as adaptation, speciation, and population structure.
The idea of a tree of life arose from ancient notions of a ladder-like progression from lower into higher forms of life (such as in the Great Chain of Being).Early representations of "branching" phylogenetic trees include a "paleontological chart" showing the geological relationships among plants and animals in the book Elementary Geology, by Edward Hitchcock (first edition: 1840).
Biogeography is the study of the distribution of species and ecosystems in geographic space and through geological time.Organisms and biological communities often vary in a regular fashion along geographic gradients of latitude, elevation, isolation and habitat area. [1]