Each of the following answer choices compares a segment of DNA from two related species that diverged from a common ancestor. Assume a mutation rate of one mutation every 60 million years applies to all segments and that a mutation can happen only once at each position in a DNA sequence. Which pair of sequences shows that the two species diverged from their last common ancestor 60 million years ago?
GATTCACT and AACTCACA

GCGCTTAT and ACGTTTGT

TATTCGCG and TATTGCCG

TCACTTAA and TCACTCAA

Question

Each of the following answer choices compares a segment of DNA from two related species that diverged from a common ancestor. Assume a mutation rate of one mutation every 60 million years applies to all segments and that a mutation can happen only once at each position in a DNA sequence. Which pair of sequences shows that the two species diverged from their last common ancestor 60 million years ago? 
GATTCACT and AACTCACA

 GCGCTTAT and ACGTTTGT

 TATTCGCG and TATTGCCG

 TCACTTAA and TCACTCAA

thomaster · Answer

1st one shows 4 mutations
2nd one shows 3 mutations
3rd one shows 2 mutations
4th one shows 1 mutation