A molecule that can be used as a molecular clock has a neutral mutation rate of one mutation per 20 million years. How many years ago did two species share a common ancestor if the molecules found in these two species differ by a total of six mutations?

Question

anonymous · Answer

This is straight-forward enough. You have the relation 1mutation/20my and you have the number of mutations. If I'm not mistaken, you just multiply 6*20milyrs to get 120 million years ago.