Hi All
I emailed Tim Bromage on the new ER1470 reconstruction and just how he got the new brain volume. His reply was interesting, though he clearly has issues with the paleo-anthro “mafia”.
My email…
Hi Tim
I’ve been watching various science-bloggers discuss your recent poster at IADR and several have been critical (or jealous) of the media attention given to your new reconstruction, especially the new brain volume. Interestingly no one has mentioned Alan Walker’s reservations about Leakey’s original reconstruction, which he discusses in his book “The Wisdom of Bones” – as he puts it the facial angle was crucial to the perceived affinities of the skull, and he felt it was more Australopithecus and less Homo. Bernard Wood has seemingly backed that point of view by renaming ER1470 Australopithecus rudolfensis.
To the point, John Hawks takes issue with your reconstruction’s brain volume here… http://johnhawks.net/weblog/fossils/habilis/er/bromage_1470_2007.html
His is the only substantial criticism I’ve seen so far, so I’m curious: how did you arrive at the new brain volume?
sincerely
Adam Crowl
…and Tim’s reply, which promises a full paper…
Hello Adam:
Indeed, all that you say is true. I have mentioned Alan’s views to all
interviewers that have picked up on the poster, but it is no surprise
that we have little impact on how the stories are written.What I have also found to be true is that ignorance is the paramount
factor behind most, if not all, of the criticism I have heard.The reconstruction of the brain volume was trivial. Of course, the
problem of determining this in 1972 was due mainly to the lack of
biological principles. The craniofacial growth and development folks
had certainly little to say, even the comparative mammalian (let alone
primate) people. Never mind, this did not stop the reconstruction from
becoming hardened at a quite high number, thus satisfying the need.
This perspective, like Alan had warned, also found its way into the
pitch of the face on the skull. Oh well.Biologically-based criteria now exist and determine where the face must
be in tissue space, not where I or anybody else THINK it was. Having
established this, it transpires, for good reason, that there is a
statistically significant relationship between brain size and facial
prognathism, which Francis Thackeray and colleagues observed (Francis is
a co-author on the abstract and paper in preparation). The facial
prognathism now determinable, it was a simple matter to subject the
numbers to the formula for obtain brain volume (526cc +or-49).Thanks for your reasoned remarks. The problem with the field
responsible for making the criticisms, is that the science is lacking,
and lacking this, the only course of action is to climb the hill and
start shooting off the cannons. I could hardly be more disinterested.
This field has a desperate problem that I fear it will not recover from;
it is obsessively protectionist and closed, and I will have nothing of
it. I don’t need controversy to satisfy my ego. I could have cared
less if no one reported on this poster. I do care about good science
and open dialog however. Let’s see where the published paper takes us.Tim
…so as you can see he has more faith in known developmental dynamics, than subjective reconstructions by paleoanthropologists with an axe to grind. I think that’s a fair call. The ensuing debate will be important to observe because it might be an injection of objective analysis into a rather “imaginative” field.
Personally, from what I’ve read of other H. rudolfensis finds and putative H. habilis remains, we’re looking at a transitional population between Australopiths and Ergaster/Erectus. The Dmanisi hominids bridge the latter-half of the divide quite neatly and I think they share affinities with the much more poorly preserved Habilines, as well as being obviously Ergasts. So imagine the sequence like so…
South Apes => Habilines => Dmanisi => Ergaster/Erectus => late Homo
…but along the way there were side-branchings, like the Asian erects, the Hobbits, the Neanderthals. And, in the other direction, it wouldn’t surprise me if we discover that Pan and Gorilla branched off from the early South Apes, since the branching time has been brought forward to a mere 4 mya.
Doubtless more surprises await.