A very simple visual explanation of how speciation works, ideal for use for a GCSE science class.

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.