Just after I finished writing The End of Adam and Eve: Theology and the Science of Human Origins, I came across a newly published article suggesting its better to think of human TRANSITIONS than human ORIGINS. The main reason is that when we try to find the moment when humans began to exist, all we can discover are transition points. The article by Robert Foley and others is available here.
I agree entirely with the point being made here. We cannot find the moment when human first began, simply because there is no moment to find. This is a point I make again and again in my book. But as Foley and others note, “And yet we know that there was a time when something did not exist—humans—and then a time when they did? How do we discover the process, timing and causes of such a change?” What that suggests is that the transitions add up to something new.
But what is meant by “transitions”? Are they best seen as big moments of dramatic change? No, Foley and others claim. Big changes are composed of smaller changes:
Looking at the totality of hominin evolution, there is no broad division between the earlier and later phases, nor between archaic and modern humans. These transitions are significant, but the richer fossil record now in existence, and the multiple techniques available for studying it, show that the major transitions of human evolution are comprised of multiple smaller ones.
Or just in case this is not clear enough, the authors reiterate the point later in the article. Of course it’s true, they say, that major changes have occurred in human evolution. In many ways we are different from our ancient ancestors. “Humans in the course of their evolution have undergone major changes, but…the evolutionary record…shows that it consists of many smaller cumulative changes, not a single major transition.” Here again, this fits very well with what I suggest in The End of Adam and Eve.
But I am not willing to give up on the question of human “origins.” In fact, it is interesting how both words—origins and transitions—need to be carefully defined in much the same way. Simply put, there is no “origin” of humanity, and there is no “transition” that makes us human. There are, instead, many transitions and multiple origins of the complex features and behaviors that make us human.
I highly recommend this article, mainly because it offers a current, authoritative overview of recent developments in human evolution.