Search results
Results from the WOW.Com Content Network
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 ...
Mayr's definition has gained wide acceptance among biologists, but does not apply to organisms such as bacteria, which reproduce asexually. Speciation is the lineage-splitting event that results in two separate species forming from a single common ancestral population. [15] A widely accepted method of speciation is called allopatric speciation.
On the Origin of Species (or, more completely, On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life) [3] is a work of scientific literature by Charles Darwin that is considered to be the foundation of evolutionary biology. It was published on 24 November 1859. [4]
[134] [135] Charles Darwin was the first to describe the role of natural selection in speciation in his 1859 book The Origin of Species. [136] Speciation depends on a measure of reproductive isolation, a reduced gene flow. This occurs most easily in allopatric speciation, where populations are separated geographically and can diverge gradually ...
Peripatric speciation is a type of allopatric speciation that occurs when one of the new populations is considerably smaller than the other initial population. This leads to the founder's effect and the population can have different allele frequencies and phenotypes than the original population.
In animals, ecotypes owe their differing characteristics to the effects of a very local environment which has been hypothesized to lead to speciation through the emergence of reproductive barriers. [ 12 ] [ 13 ] [ 14 ] Therefore, ecotypes have no taxonomic rank .
This concept Ernst Mayr proposes here is now commonly referred to as the biological species concept. The biological species concept defines a species in terms of biological factors such as reproduction, taking into account ecology, geography, and life history; it remains an important and useful idea in biology, particularly for animal ...