|Berna et al. 2012 Microstratigraphic evidence of in situ fire in the Acheulean strata of Wonderwerk Cave, Northern Cape province, South Africa. PNAS online.|
I’m starting to feel slighted. Tell me why I shouldn’t.
Either Francesco Berna and Paul Goldberg are so far out in the field that they’re incommunicado and have been for a while, or they’re too embarrassed by their fireplace faux pas at Wonderwerk Cave that they’re playing it cool.
Paul is someone I’ve known for decades. I’ve never met Francesco. When my recent blurt on the matter called into question their claims, I expected an immediate response–so devastating is the overlooked evidence. Yet, crickets chirping was all I heard. Then I emailed Don Grayson, well-known to most of you, who was the National Academy member who acted as the editor for the paper in PNAS. He was intrigued, and thought I ought to pursue the publication route. But I thought it better to email Francesco and Paul instead, a week or so ago, hoping to stir them into some sort of response to my contention, i.e. that finding no Fourier Transform Infrared Spectrographic evidence of Berlinite in the sediments at Wonderwerk Cave can’t be used to rule out spontaneous combustion of bat doo-doo in the 1.0 Myr old deposits.
|Home, Sweet, Homo erectus Home (Source):
Home is Where the Hearth Is.
Theirs is no small inference. An Acheulian Prometheus is big news. No doubt about it! It’s not the sort of thing you want to make a mistake about, especially when the mistake you’re making is to ignore or to be, evidently, ignorant of the formation temperature of Berlinite [something you would have thought a geochemist and a geomorphologist might have thought to investigate before they made their claim for the controlled use of fire so long ago by Homo erectus–or H. ergaster, whichever you prefer–a species long since extinct–unless you accept that H. Floresiensis is a dwarf relict population, which I happen to do, but which is beside the point in this discussion, albeit really interesting and kewl].
Remember that no ‘hearths’ were recorded at Wonderwerk Cave; the excavators instead base their inferences on the presence of heat-altered sediments across a wide area in the million-year-old cave deposits. Unfortunately, the authors report no evidence for temperatures above 550° C, and Berlinite will not form below 583° C. But then, you already know this, ’cause I’ve written about it here.
So, although I’m repeating myself, I’d like to call on the authors–either, any, or all–to respond to my question about their observations, and to comment on the temperatures required to alter the chemistry of the plant and animal remains they recovered, together with their conclusions that Berlinite would surely have been visible if spontaneous combustion of bat guano (a well-known and well-documented phenomenon) had been responsible for the raised temperatures in the cave sediments.
I’m waiting, gentlemen.
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