Crowdsourcing the Paleolithic
“Armchair archaeologist” used to be a derisive term, belittling those who claimed a passionate interest in the ancient past but lacked the gumption to do anything about it. These would-be participants avoided the rigors of training and the possible sting of public failure simply by staying home. Now, however, the Turkana Basin Institute in Kenya and the University of Bradford, England, have devised a way for armchair explorers to participate in fieldwork all the way from home (provided, that is, they can reach the Internet from their armchair). If you’re dedicated, patient, and—above all—observant enough, you can help paleoanthropologists in the field uncover traces of our remote ancestors on the terrain of East Africa.
For my part, having realized long ago that I entirely lack the gumption to become a paleoanthropologist, I was thrilled to hear that this project, called Fossil Finder, had become available on the online citizen-science platform Zooniverse. I hurried to find the home page.
The rationale of Fossil Finder is straightforward: Surveying a large expanse of land for slight irregularities of color or pattern or texture is an agonizingly slow process, like a game of “Where’s Waldo?” in which every person, place, and thing is exactly the same color. (Strictly speaking, of course, the terrain of the Lake Turkana Basin is not all exactly one color: there’s brownish, grayish, and whatever you call the peculiar hue in between. Say, two and a half colors.) It seems only reasonable that the researchers would want as many eyes as possible examining the site, even if most of the views come from people who may never actually set foot on the terrain. If several people, participating from somewhere in cyberspace, independently point out the same patch of ground as looking somehow different from its surroundings, the researchers in the field can go straight to that spot, examine it for themselves, and perhaps find a tooth, a fragment of fossilized bone, or a flake struck from a rock core some million years ago by hands eerily similar to our own.
To make the site available for surveying on computer screens all over the world, the valiant folks at Fossil Finder have uploaded an untold number of close-up photographs, each presenting a patch of ground 34 centimeters (about 13.4 inches) wide. Most of these shots, such as the one below, are unremarkable at first glance.
But the instructions call for more than a glance, posing a series of increasingly specific questions. The answers supplied by online participants will help guide the experts on site in Kenya toward the most promising locales. First it’s necessary to determine whether a particular patch can be studied by photo at all; for instance, the photographed area may be too much in shadow or covered by vegetation. Another option listed for ruling out photos is “Too Blurry,” but you’ll rarely need to choose that response. For the most part the images are remarkably sharp, with a ground resolution of about 0.3 millimeters, or one-eightieth of a foot.
If the photo merits close study, you’re asked to estimate the proportion of the image that’s covered by loose rubble and then decide the type(s) of rock and/or mineral being shown:
At this juncture the button labeled “Need some help with this?” is very helpful, offering clear visual examples and explanations for those of us who don’t know our calcrete from our quartz. But the distinctions don’t end there: Several of these types of stone come in subtypes, which must also be identified. Sandstone comprises six different types, not just fine or coarse but also fossil-rich, bioturbated (restructured by living organisms during its formation), laminated, or conglomerated (a little of everything). Claystone may have a yellow, olive, gray, or white hue, each hinting at a different origin.
More often than not, a single photo will show two or more types of rock or mineral, but you need only identify the two or three that seem most prevalent.
Then you get down to “items of interest”—the reason you’re peering so carefully at this patch of ground in the first place. Do you think you see part of a fossil bone or a tooth?
Is that a stromatolite—the fossilized biofilm that can grow around a shell? Maybe a root-cast or a rhizolith? (Again, thank goodness, the “Need some help?” button leads to examples that show you what’s what.)
How about a fossil shell or perhaps, just possibly, a stone tool? There’s even a label made to order for those of us with the most eager, untrained eyes: the vague but hopeful “Might be something.” Mark the spot(s) with the appropriate icon(s), and you’re soon done. Moving on to another photo, you may see something like this:
which you can reject, under the heading of “Too Bushy.” On to the next sample of terrain. . . . And so you labor on, virtually, under the bright east African sun. Who knows what you may discover next from the comfort of your armchair?
This post is published in Science Culture