"Common ancestry" refers to the idea that different organisms or species share a common biological ancestor, meaning they are all related and come from the same original form of life. Full definition
I find it almost impossible to believe I share common ancestry with the guys who are into mixed martial arts and anything else that involves beating the hell out of another human being. (sarahbessey.com)
In terms of common ancestry, there is in fact very little fossil evidence or biological evidence that suggest the life evolved from simple compounds. (religion.blogs.cnn.com)