It was pretty clear what I was driving at with the contrast between the National Geographic 2M+ years impression of the origin of humanity versus the Genesis impression. For 97% of that 2,300,000 years, those creatures didn’t have sophisticated language as we know it. You can define humanity by tool-making, I suppose, but I don’t see why you couldn’t just as arbitrarily choose upright walking and go farther back, or choose complex language and go farther forward in development for the arrival point.
Necessary tangent: I will do a separate but short post on why complex language did not develop over tens of thousands of years but sprang up rapidly once a tipping point (probably a genetic one) was reached. There would be some foundation, certainly. It would have been more advanced than the communications of baboons, presumably. But the change would not have been gradual.
Nor are we stymied at the 50-60,000 year range of having to unreservedly call them people just like us either. I personally think that language is a good dividing line, but if someone wanted to get stickier – get more technical – there are a lot of things about that group that still aren’t like us. They don’t have permanent dwellings. No domesticated animals or agriculture. No metalworking, living in villages. No trade as we know it, or getting along with groups larger than one’s own band. We are seeing some interesting stuff, however: in addition to the spears they’ve had for a long time, we’re starting to see bows and arrows; they are not only throwing furs around themselves for protection, they are even beginning to sew pieces together with big bone needles to make garments. Something like art, music, and religion might be developing. Once you know our history, they are clearly becoming us. They are significantly different from other animals. But where we put the finish line is an interesting question.
To cut to the chase: when do we see this suite of behaviors that tells us okay, those are humans as much as we are, we can no longer deny it. Anyone? Intergroup contact increases during an Ice Age about 18,000 years ago. Dog domesticated, 12,000; other animals over the next few thousand years. Semi-permanent dwellings, agriculture, surplus and trade, about 8,000 years ago. I don’t think we want to put the finish line that close. Certainly we don’t want to put it at the development of writing, or cities, or the like, as there are cultures now that don’t have those things and yet are indisputably human. But we are in Genesis range, aren’t we? We are 99% of the way from Olduvai to today just to get some cooperation beyond the level of the tribal band.
Our Martian landing today, looking at the humans talking, writing, spread out over the whole planet, building cities, making electricity, would love to have the data from our scientists about exactly when these changes happened, and would no doubt reject the Genesis 6000 years as a suitable time frame. But if our current secularists tried to push the issue too far, trying to get him to go up and speak before the United Nations and put all those myths to rest once and for all he might demur. He might look at the first few chapters of the anthropology textbooks and say they were technically correct but essentially misleading. To counteract the myth of gradual progress, he might recommend that children read something like Genesis, just to get the basic – and perhaps more important – concept of how quickly and recently this all occurred into their cute little craniums. (No, it shouldn’t be crania. Singular forms that have embedded into English take English plural forms, not the plurals from their language of origin.)
There are three major objections to the Genesis story: time scale, location, and number of original humans. I think I've taken care of time scale and will move on to the others. You might begin to guess some of my points.