A molecule that can be used as a molecular clock has a neutral mutation rate of one mutation per 5 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 eight mutations?
Answer
a) 1.5 million years
b) 10 million years
c) 20 million years
d) 40 million years
( is it A? not sure)

Question

A molecule that can be used as a molecular clock has a neutral mutation rate of one mutation per 5 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 eight mutations?
Answer
	a)	1.5 million years
	b)	10 million years
	c)	20 million years
	d)	40 million years
( is it A? not sure)

blues · Answer

I think it's D.

It tells you that there is 1 mutation every 5 million years.

So after 5 million years, there is one mutation. After 10 million years, there are two mutations. So after 40 million years, there will be 8 mutations.

blues · Answer

Clear?

anonymous · Answer

yes now I understand !

anonymous · Answer

It's actually 20 million, because there are two species