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

Vicariance or simply geographic isolation due to man-made or natural barriers

I think the accurate answer to this question, based from the sources,  is vicariance. This type of evolution is isolating one population from the other which results to speciation by geographic isolation. Thank you for your question. Please don't hesitate to ask in Brainly your queries

Answer 2

The answer is that the lizards on one side of the mountain were exposed to different conditions and therefore different characteristics were selected.