We can think of this shape as a neutral evolutionary trait that gradually spread through the population, he says. (newscientist.com)
Therefore, maturing early would be an essential evolutionary trait for survival. (totallygoldens.com)
But good ideas, like useful evolutionary traits, tend to emerge more than once, in diverse times and places, and the idea of arranging for parts to roll against one another instead of sliding or slipping is very old indeed. (scientificamerican.com)