A Gene Family That Codes for Various Hormone Receptors Has

Multiple Choice

A gene family that codes for various hormone receptors has been accumulating nucleotide substitutions at a rate of 0.4 substitutions per million years.On average, there have been 60 substitutions between the common ancestor of this gene family and each of the various living forms of this gene.Based on these numbers, this hormone receptor gene family likely originated _______ million years ago.

A) 15
B) 24
C) 75
D) 150
E) 300