Speciation is the process by which a new species evolves from an original species through natural selection. It occurs when a population is divided into isolated subgroups by a geographical barrier, such as a river or earthquake, causing each subgroup to evolve differently over time to adapt to their separate environments, resulting in genetic differences that prevent interbreeding if they were to come back into contact.

1. Speciation
By James Holmes

2. Speciation is the creation of a new
species from an original founder
species, through the process of
evolution. This is how it works.

3. A population of a particular species
inhabits an area

4. A geographical barrier forms (e.g an earthquake
splits the land, or a river forms) which divides the
population into 2 sub-groups, which are now
reproductively isolated from each other.

5. There are different environmental conditions on
each side of the barrier, and through natural
selection, each sub-group evolves differently the
meet the needs of their own environment. In this
example, organisms evolve different camouflages to
match the different environments.

6. Over time this causes the two sub-groups to
become so genetically different that if they were to
be reunited, they wouldn’t be able to successfully
interbreed – they have become two separate species.