In the distant future I see open fields for far more important researches. Psychology will be based on a new foundation, that of the necessary acquirement of each mental power and capacity by gradation. Light will be thrown on the origin of man and his history. – some dude.
We are a dreadfully narcissistic lot. Perhaps nothing in the Origin has inspired more reflection or revulsion than Darwin’s passing reference to the promise that his ideas had to illuminate the origins of our own species. Creationists might bloviate about bacterial flagella or blood-clotting proteins, but most are surprisingly willing to concede the fairly obvious genetic relations between, say, camels and llamas separated by two oceans and millions (or in the case of YECers maybe six thousand) years. They even have a wonky pseudoscience, baraminology, that more or less admits that yes sister taxa have a common origin…up to a point.
But when it comes to one particular species, they invariably draw the line. Of course as Darwin rightly anticipated, much has been learned in the last century and a half about the origins of our own species–it’s not my intention to review the history of these discoveries here, but I highly recommend Brian Switek’s comprehensive historical analysis as a great place to start. But while much light has been thrown, perhaps an equal measure of ink has been shed in an attempt to visualize the evolutionary history of Homo sapiens.
Darwin’s own back of the envelope attempt seems, perhaps surprisingly, among the most straightforward of the lot, despite the bet-hedging and scratchouts:
It’s mostly been uphill from there, but often up the wrong the hill. Like a teenager flexing in the mirror, then agonizing for an hour over a newly discovered blackhead.
I was reminded of all of this by this recent post by John Wilkins that reproduced this figure:
As they go, this diagram is not particularly bad, though as Wilkins notes the form does seem a bit dated. However, I think that the discussion in the comments to that post reveal why this diagram is perhaps at least as confusing as it is revealing: are those truncated side-branches based on fossil data or just hypothetical? Is the light brownish region supposed to be denoting some area of uncertainty and if so how? Is there a 3rd dispersal out of Africa implied? What exatly do those “?”s mean? (To be fair, I haven’t seen the figure caption which may address some or all of these questions.)
So, here then, gleaned from google are various other diagrams each ostensibly depicting more or less the same events: 5 million years of ape evolution in Africa plus some things that came after. Feel free to leave your Tuftian critiques in the comments, bonus points for dropping fashionable jargon like “chart junk” “data-ink-ratio” &c.