gene flow genetic drift natural selection random mutation
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: A population of plants growing on an island consisted of two varieties, one with thorns and the other without. Over a period of many years, the variety with thorns gradually disappeared. Which process most likely brought about this change in the plant population?
Possibilities:
- gene flow
- genetic drift
- natural selection
- random mutation

natural selection