Question

A population of lizards were living in an area that began to experience a great amount of mountain building. As the mountains formed some lizards were on one side of the mountains and the rest were on the other side of the mountains. Over a period of many years the lizards were no longer able to breed, or had become different species. Why did this happen?

Answer 1

In order to live in certain conditions the lizards had to adapt to the area in order to live. From adapting they are no longer able to breed.

Answer 2

They became adapted to their new environment and became new species which then were not able to produce fertile offspring.