Speciation is a term used to describe the process of creation of sub species of plants and animals, usually through changes in habitat or environment. Speciation can also be artificially caused by deliberate breeding. This process was first identified in changes in island species which were formerly mainland species. Speciation causes morphological and genetic changes in affected organisms. These changes are often profound biological changes, although such changes are also evident in less dramatic adaptions and minor changes.
Examples of Speciation:
Darwin's examples of finch species as distinct from ancestral forms.
Fruit flies (Drosophila): Multiple different species descended from originals
The three-spined stickleback.
Speciation via polyploidy: A diploid cell undergoes failed meiosis, producing diploid gametes, which self-fertilize to produce a tetraploid zygote.
Comparison of allopatric, peripatric, parapatric and sympatric speciation.