WASHINGTON (Reuters) –
Genetic material pulled from a pinky finger bone found in a Siberian cave shows a new and unknown type of pre-human lived alongside modern humans and Neanderthals, scientists reported on Wednesday.
The creature, nicknamed "Woman X" for the time being, could have lived as recently as 30,000 years ago and appears only distantly related to modern humans or Neanderthals, the researchers reported.
"It really just looked like something we had never seen before," Johannes Krause of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, told a telephone briefing.
"It was a sequence that looked something like humans but really quite different."
Writing in Nature, Krause and colleagues said they sequenced DNA from the mitochondria, a part of the cell, which is passed down virtually intact from a woman to her children. They compared it to DNA from humans, Neanderthals and apes.
The sequence indicates the hominin's line diverged about a million years ago from the line that gave rise to both humans and Neanderthals and that split about 500,000 years ago.
That makes it younger than Homo erectus, the pre-human that spread out of Africa to much of the world about 1.9 million years ago.
"It is some new creature that has not been on our radar screen so far," said Svaante Paabo, a colleague of Krause's who specializes in analyzing ancient DNA.
And it would have lived near to both modern humans and Neanderthals. "There were at least three ... different forms of humans in this area 40,000 years ago," Paabo said.
Krause and Paabo are careful not to name the creature a new species just yet. They are now working to sequence nuclear DNA -- the DNA that makes up most of the genetic code, which will tell a great deal more about "Woman X".
NEW SCIENCE OF EVOLUTION
The genetic sequence tells scientists little about what the creature would have looked like or whether it interacted with other humans living in the Altai mountains of Siberia, where the pinky finger bone was found.
The work, done using a DNA sequencer made by Illumina Ltd, suggests a new way is opening to identify the ancestors of humanity. Krause and Paabo had only a tiny fragment of bone to work with and cannot reconstruct a skeleton in the time-honored manner of most paleontologists.
But there may be more there. The cold, dry conditions of the Altai mountains preserve the DNA. Stone tools also have been found in the area, as well as the bones of woolly mammoths but only tantalizing fragments of human bone and teeth.
Researchers have sequenced DNA from mammoths frozen in Siberia and the same team has sequenced DNA from Neanderthals.
Paabo and Krause said it is theoretically possible the creature is related to another potential third species of human -- Homo floresiensis, nicknamed "hobbit" -- which lived on an island in modern-day Indonesia about 17,000 years ago.
The team has tried without success to get DNA from hobbit bones. Most skeletons of pre-humans have been found in warm places such as Africa, but hot, wet conditions break down DNA.
Past research has shown that when people are concealed from view by others, say when they are wearing hoods, these individuals will be more likely to commit criminal acts and other bad behaviors.
But what about times when we're not actually anonymous - people can see us - yet we feel like we're hidden? The researchers of the new study describe it as the adult version of hide-and-seek: Kids often believe no one can see them when they cover their eyes even though they are hiding in plain sight. Turns out, a dark room can have a similar psychological effect on adults.
The results could play out in real-life office behavior, the researchers say. "Imagine that a person who is alone in a closed room is deciding whether to lie to a total stranger in an e-mail. Clearly, whether the room is well lit would not affect the person's actual level of anonymity," Chen-Bo Zhong of the University of Toronto's Rotman School of Management and colleagues write in a recent issue of the journal Psychological Science.
In one experiment, 84 college students were placed in a dimly or well-lit room and were given two envelopes - one containing $10 and the other empty. Participants then had five minutes to complete a test in which they had to pick out two numbers that added up to 10 from each of 20 matrices. For each pair of numbers correctly identified participants could keep $0.50 from their money supply. The catch: Participants scored their own work, and they figured out how much money they got to keep, and transfer to the empty envelope, at the end of the experiment.
They all fared the same on the tests, though participants in the dim room cheated more than their counterparts. While those in the well-lit room reported an average of 7.8 correctly solved matrices, the dim-room students indicated an average of 11.5 correct responses. That resulted in a $1.85 difference in payout.
In another experiment students wore sunglasses or clear glasses while playing a money game in which they had to allocate some portion of $6 to a random stranger. Those wearing shades acted more selfishly, giving significantly less to partners, an average of $1.81, than did those with clear glasses who gave about $2.71 to partners.
Another round of this game with a different group of students showed that participants with sunglasses felt a greater sense of anonymity than those with clear glasses. For instance, the sunglass wearers were more likely to agree on average with statements such as: I was anonymous during the study; my choice went unnoticed during the study. And they were more likely to disagree with: I was watched during the study; and others were paying attention to my behavior during the study.
- Original Story: Darkness Begets Dishonesty, Study Finds