Which circumstances are necessary for a new species to form?
The isolation must last long enough for organisms to evolve differently.
Group members must be separated by a mountain range or volcano.
Members of a species must only be separate for a short time.
The separation must still allow the two groups to produce offspring together.
Genetic mutations and natural selection must occur in the isolated groups.
There must be a change in the environment that creates new ecological niches for the isolated groups.
There must be reproductive isolation between the two groups, preventing them from interbreeding and exchanging genetic material.
Over time, the genetic differences between the two groups must become significant enough that they can no longer produce viable offspring together.
Eventually, the two groups will have evolved into distinct species.