Coevolution is the change of a biological object triggered by the change of a related object. And up until now there has been little evidence of it driving changes in Earth's history, though that, too, seems to be changing:
A new University of Georgia study shows that some native clearweed plants have evolved resistance to invasive garlic mustard plants—and that the invasive plants appear to be waging a counterattack. The study, published in the early edition of the journal Proceedings of the National Academy of Sciences, is thought to provide the first evidence of coevolution between native and invasive plant species.
"The implications of this study are encouraging because they show that the native plants aren't taking this invasion lying down," said study author Richard Lankau, assistant professor of plant biology in the UGA Franklin College of Arts and Sciences. "It suggests that if you were to take a longer view—a timescale of centuries—that exotic species could become integrated into their communities in a way that is less problematic for the natives."