|Evolution in the News - July 2013|
|by Do-While Jones|
Telling tales for fun and profit.
National Geographic devoted 14 pages of this month’s issue to a largely fictional story about Denisovans, a third subspecies of human beings, all of whose fossils would fit in a shot glass. Here are the few actual facts in the story.
In the back of the cave is a small side chamber, and it was there that a young Russian archaeologist named Alexander Tsybankov was digging one day in July 2008, in deposits believed to be 30,000 to 50,000 years old, when he came upon a tiny piece of bone. It was hardly promising: a rough nubbin about the size and shape of a pebble you might shake out of your shoe. … The bone preserved just enough anatomy for the paleontologist to identify it as a chip from a primate fingertip—specifically the part that faces the last joint in the pinkie. Since there is no evidence for primates other than humans in Siberia 30,000 to 50,000 years ago—no apes or monkeys—the fossil was presumably from some kind of human.
… [T]wo other fossils had been found to contain DNA similar to that of the finger bone, both of them molars. …
Remarkably, that tooth was even bigger than the first, with a chewing surface twice that of a typical human molar. It was so large that Max Planck paleoanthropologist Bence Viola mistook it for a cave bear tooth. Only when its DNA was tested was it confirmed to be human—specifically, Denisovan, as the scientists had taken to calling the new ancestors. “It shows you how weird these guys are,” Viola told me at the symposium. “At least their teeth are just very strange.” 1
It’s too big to be a human tooth. It looks just like a cave bear tooth. The only reason to believe it isn’t a bear tooth is an analysis of its DNA, which has allegedly had more than 30,000 years to degrade and become contaminated. What more evidence could you ask for?
To date, no other fossil has been identified as Denisovan by the only way Denisovans can be known: their DNA. 2
Because the DNA of the (presumably) finger tip bone didn’t contain a Y (male) chromosome, they concluded the finger belonged to a girl. They kept digging.
For a while they thought they might have her toe too. In the summer of 2010 a human toe bone had emerged, along with the enormous tooth, from Layer 11. In Leipzig a graduate student named Susanna Sawyer analyzed its DNA. At the symposium in 2011 she presented her results for the first time. To everyone’s shock, the toe bone had turned out to be Neanderthal, deepening the mystery of the place.
The green stone bracelet found earlier in Layer 11 had almost surely been made by modern humans. The toe bone was Neanderthal. And the finger bone was something else entirely. One cave, three kinds of human being.
Putting all the data together, Pääbo and his colleagues came up with a scenario to explain what might have occurred. 3
It’s a fascinating scenario! But, since it is only a story, it isn’t worth repeating. Let’s cut to the chase.
This scenario might explain why the only evidence so far that the Denisovans even existed is three fossils from a cave in Siberia and a 5 percent stake in the genomes of people living today thousands of miles to the southeast. But it left a lot of questions unanswered. If the Denisovans were so widespread, why was there no trace of them in the genomes of Han Chinese or of any other Asian people between Siberia and Melanesia? Why had they left no mark in the archaeological record—no distinctive tools, say? Who were they really? What did they look like? “Clearly we need much more work,” Pääbo acknowledged at the Denisova symposium. 4
In the end, it all comes down to money. “We need much more work.” The only way for this research to be funded is by telling an interesting enough story that someone will pay to read it. Paleontologists don’t provide a service or sell a product—they tell stories. It is their only form of income. They have to sell stories to pay the bills.
National Geographic needs stories to fill their magazine each month. They pay for stories that will sell magazines (especially if those stories advance their obvious political agenda). Paleontologists produce stories that National Geographic will publish. It’s just that simple.
OK. I take that back. It isn’t simple to create a whole race of people out of one bone fragment and two teeth. It takes a lot of skill and creative oratory to create the story. Bravo to them!
Just because they are doing it for the money doesn’t mean they don’t believe it. They really do believe the stories they tell. But there is no reality check to show them they are wrong.
Engineers do it for the money, too. The difference is that an engineer who truly believes in his radical new radio design has to build a prototype radio using that design. If it works, it proves he was right, and he makes money selling the design to a manufacturer. If it doesn’t work, it proves he was wrong.
Since it is impossible to observe what happened in the prehistoric past, and it is impossible to do any experiments that confirm or disprove the story about a mythical extinct race of people called Denisovans, that story isn’t really scientific, and should not be given the same credibility as real science.
|Quick links to|
|Science Against Evolution
|Back issues of
of the Month
Jamie Shreeve, National Geographic, July 2013, “The Case of the Missing Ancestor”, pages 90-103, http://ngm.nationalgeographic.com/2013/07/125-missing-human-ancestor/shreeve-text