There are some vital issues to be separated and resolved in this mini-drama. First of all, opposing theorists habitually use the same terms for different concepts: in this case, “Bipedal”, as in: did we or didn’t we become bipedal when we emerged from the savannah? This happens not just “often” but almost always, at least somewhere, in tricky evolution arguments.
You forgot to say “It depends what you mean by…”
This causes chaos of course, yet arguers almost NEVER search out these misunderstandings, so they rarely find or fix them. (This is because of the generally poor understanding of the nature of knowledge and its use, amongst scientists.)
Thus, those disputing whether we “became” “bipedal” when we “emerged from” the “savannah”, should first resolve “bipedal” into its two stages:
* First, habitual upright “waddling”, a bit like apes use today, but, unlike the great apes, preferring it over going on all-fours when on the ground;
* Eventually, efficient long-range walking, as apparently suggested by the Laetoli footprints, or the skeleton of Lucy (Australopithecus afarensis).
Anyone in the argument Barbara King reports, should be aware of the importance of this two-stage bipedalism, yet neither Dominguez-Rodrigo nor White seem to make use of it (though Dominguez-Rodrigo does address the ambiguity of “savannah”). In this example, are they using two different meanings of bipedal? Well, they’re definitely not using them properly. Here is the crucial junction piece of the jigsaw they should be experimenting with:
Waddling bipedalism being used in fairly or heavily tree-d areas… evolving into efficient bipedalism allowing relatively tree-free areas to be added to the viable range.
This theory is nice in a number of ways. First, both sides can be right-ish in connecting, or not connecting, “uprightness” with leaving the trees. We’ve preferred bipedal waddling when on the ground, for 20-odd million years, so no, uprightness in that sense is definitely not associated with “leaving the trees”. On the other hand, when we progressed to bipedalism 2.0, this did give us the option to stray from the trees more often (though fossils from that time might still be found “amongst trees”, perhaps sometimes, perhaps usually). Bipedalism 2.0 appeared on the scene when the first approximation to the human-like foot appeared, on Australopithecus anamensis, probably around 4.25 million years ago. They haven’t found the foot of A. anamensis yet, but it will be a bipedalism 2.0 foot, rather similar to that on Australopithecus afarensis (Lucy) and Australopithecus africanus (though the latter was going back into the trees, as it became chimp). Note, this now consolidates as “the australopithicine foot”, which we, and the chimps’ ancestors inherited, but which the chimps later dumped… and which the “other australopithicines”, aethiopicus and boisei, did not inherit, on their way to becoming gorillas (a good reason to call them Paranthropus instead).
In Barbara King’s blog post, she introduces the recent spat:
Let’s get into some specifics of the issue at hand. Dominguez-Rodrigo takes up a hypothesis familiar to many of us: Evolution of the human lineage was triggered when a primate population came down out of the trees and encountered new selection pressures on the savanna. Those pressures included a need to move greater distances across the more open landscape, a greater risk of predation and a harder time finding adequate food, and over time they selected, among other things, for walking upright – a hallmark in this context of the human lineage.
In recent years, the savanna hypothesis was challenged by the discovery in dense woodlands of certain hominins (human ancestors), early ones like Ardipithecus who lived in East Africa more than a million years before the australopithecine Lucy. Because these hominins were capable of bipedalism, it couldn’t have been the savanna that was responsible for triggering our origins.
(That’s bipedalism 1.0 she’s referring to. Ardipithecus was an ancestor not just of humans but, contra current dogma, of chimps too, and Lucy wasn’t an an ancestor of humans – see charts above. Oh – and anyone who thinks chimps and humans split 10mya is lost.)
She gives Dominguez-Rodrigo’s adjustment of the definition of savannah:
Dominguez-Rodrigo wants, however, to rescue a version of the savanna hypothesis. “The unambiguous structural definition” of a savanna, he writes, “is a landscape with a grassy cover, where trees are sparse enough to allow grass growth.” A savanna is not inevitably synonymous with a pure grassland, but rather may be made up of a variety of open and wooded habitats. In his analysis, Ardipithecus and other early hominins dwelled in seasonal mosaic environments — that is, on the savanna.
Fair enough. From her blog again, White’s response to this…
“Without original research or new data, Dominguez-Rodrigo attempts to resurrect ‘the spirit of the old savanna hypothesis’ via word games and revisionist history … This attempted resurrection of an obsolete mind-set will stand as a monument to futility.”
…in response to prehistorian M. Dominguez-Rodrigo’s article on the savannah hypothesis of human evolution [http://www.jstor.org/discover/10.1086/674530?uid=3739936&uid=2134&uid=2&uid=70&uid=4&uid=3739256&sid=21103484505261], in the February 2014 Current Anthropology.
…and Dominguez-Rodrigo’s counter riposte:
“By denying [the] evidence [for the savanna hypothesis], White exemplifies perfectly Kuhn’s idea that when a paradigm is assaulted, supporters of the old guard remain intentionally blind to the mounting evidence or selectively utilize data in order to resist change.”
D-R and Kuhn were right enough there, but it tends to happen over those pesky ambiguities, and D-R has already messed up by failing to address them … and there’s other gems in this play…
I’m in a funny position here because I side with the White Gang, or I used to, in attacking The Savannah Hypothesis, or its old-fashioned version conflating the two bipedalities. But though they are trying to sing the right tune, they’re getting it wrong, and doing it nasty too. White is suggesting, in the quote before last, that you need original research, or new data, to have the right to come up with something new. Well this episode gives the lie to that: all you might need is a timely clarification of a crucial term or two! And actually, a new theory is absolutely fine – absolutely no new evidence required:
Extraordinary claims do not require extraordinary evidence and might need no new evidence: to require it would assume theorists in the field have been perfect; it’s perfectly possible people just haven’t thought of the new theory before. Theories do not spring automatically from observations.
(Check out “2.2. Comparing theories” in chapter 2 of the book to see why; also https://sciencepolice2010.wordpress.com/2011/12/01/even-the-good-guys-extraordinary-claims-require-extraordinary-evidence-really/.)
A bit on The White Gang history – good in parts.
Remember October 2009? I think myself, Tim White and his friends, and occasionally John Hawks, must be the only people left alive who now remember that slew of revolutionary papers the White Gang (alias Lovejoy et al., et al.) published in Science, on Ardipithecus (oh yes, maybe Aaron Filler, ruefully); for so many others now, it might never have happened.
Those papers were fascinating, and the material suggested a crucial stage in chimp ancestry, and ours – Ardipithecus – walked like some kind of upright monkey. The magic feather to keep hold of while understanding Ardi is: she (Ardipithecus ramidus ramidus) didn’t knuckle walk and never had an ancestor that did. Meaning also, that our ancestors never did, and that chimps’ walked upright. But Aaron Filler was never mentioned. That was like writing the new testament without mentioning John The Baptist, and I complained bitterly to Lovejoy the lead author, who at least acknowledged that many others had complained as well. Recently in another complaint about White et al., Hawks says they’ve ignored vital evidence that goes against their theory where they say Ardipithecus of about 4.4 million years ago is the same thing as some other fossils 6 or 7 million years old. I wouldn’t be at all surprised if White et al. had done that. I’m not at all surprised they’ve promoted the importance of their special baby – Ardi (though it probably fulfilled the same niche requirements in the same ways as those 6-7myo types). Palaeos are always doing that. I suspect those older fossils are just different enough for us to want to name them differently once we find out more about them, though the revolutions in niche, locomotion etc. etc. were still in the future.
Civility might be a subgoal but the main goal is Science.
King addresses the issue of rudeness. Why can’t we just be civil in science? Because the main goal of science is doing science. When we’re all on a bus, and a passenger gets out and starts putting sugar in the fuel tank, it’s not OK to say “Never mind, let’s just all be nice.” If someone’s allowed to wreck the system, we won’t be doing science any more and there’ll be no more to be said, civily or otherwise. In the absence of formal procedures to defend against cheats, making pointed criticism alerts others to the problem and the perpetrator.
In this case, both sides, Dominguez-Rodrigo’s and the White gang, both thought the other was being stchyooopid because of confusion over the terms “bipedal”, “left”, and “the trees”. This is why so many scientific discussions include, or should include: “It depends what you mean by…” near the start.
But then, as King points out, it all turns into a matter of honour. And honour in science is about status. Why should we worry about status? Who are those pathetic people who judge scientific disputes not by the science itself but by the reputation of the disputants? Who? Everyone who doesn’t know anything about the subject, but also just about everyone who thinks they do, particularly those who understand nothing except the importance of influencing the media, and getting in with others like that. This is what passes for science in palaeontology.
That’s not you, of course! And not me! But in my case I state explicitly the scientific process I use. Try to criticise me and you must either criticise my guidelines or the way I follow them.
Where do you specify your process?