10.3 Gene pools and speciation
We can use the definition of a species as a breeding group of organisms or more formally a reproductively isolated gene pool.
Evolution means that species is a problematic concept. Species change over time and there gene pools and allele frequencies also change. A species exist as an identifiable group of very closely related organisms that have a common range of genetic and morphological characteristics. They are able to or potentially able to breed with each other to produce fertile offspring. These are distinct from other genepools and reporoductively isolated from these gene pools.
Species and speciation
If an existing species (gene pool) become split into different parts these may remain isolated from each other for changes in the gene pool to occur so that they then become permenantly reporoductively isolated from each othe. This would lead to new species being formed.