Comparable segments of the mitochondrial DNA sequences of two similar species are shown below. This segment of DNA mutates at a rate of one base pair per 33 million years. Based on these DNA sequences, how long ago did the two species diverge from a common ancestor?
Species A mtDNA sequence: TACAAGATAC
Species B mtDNA sequence: TACGCGTAAC
99 million years ago
33 million years ago
66 million years ago
132 million years ago