gene flow natural selection genetic drift mutation
I gave my students this multiple choice question: A population of tree-climbing lizard lives on one bank of a large river. The other bank of the river is a treeless prairie. During a flood, 40 lizards were transferred to the prairie side of the river. After 200 generations, this transferred population of lizard lost the ability to climb.Which mechanism is most likely responsible for this loss of function within the transferred population?

Only one answer is correct among these 4 choices:
- gene flow
- natural selection
- genetic drift
- mutation

Could you tell me which one is correct?

genetic drift