James Owen in London for National Geographic News
Five adult siblings who can walk only on all fours have been found in Turkey, researchers say. These human quadrupeds may provide clues to how humans evolved to stand on two feet.
The three sisters and two brothers may offer insight into the way our apelike ancestors moved, according to scientists. Human ancestors are believed to have begun walking on two legs more than three million years ago.(See "Fossil Pushes Upright Walking Back 2 Million Years, Study Says.")
Discovered in a remote area of southern Turkey last summer, the family of ethnic Kurds has sparked a scientific debate, which will be covered in a BBC television documentary that is set to air on March 17 in the United Kingdom. The family's exact location and last name have not been disclosed.
Born with a genetic brain abnormality, two of the sisters and one of the brothers are thought to have only walked on all fours their entire lives. The two other siblings can walk upright for short distances.
The siblings' parents are closely related and have had 19 children in all.
This bizarre case is not a hoax, according to experts who have studied the family.
The cause of the four-limbed locomotion, however, is a bone of contention among the researchers.
Uner Tan is a neurophysiologist—a doctor specializing in the functions of the brain, spinal cord, and nerves—at Cukurova University in Adana, Turkey.
He believes the siblings, who range in age from 18 to 34, are evolutionary throwbacks—a "missing link" to our forebears. (Related reading)
Meanwhile German geneticists believe the siblings' genetic abnormality may have knocked out the gene responsible for bipedalism, or two-legged walking, in humans.
The German team, led by Stefan Mundlos of the Max Planck Institute in Leipzig, says it has located this gene on a human chromosome. (See a quick overview of human genetics.)
Full story here NATIONAL GEOGRAPHIC NEWS
8 comments:
Oh wow, I have to say that even with the links provided, I still can't help but be skeptical!! I'm really interested in seeing this documentary!! I have so many questions. Are their arms longer? How have their hands developed (are they flatter and bigger)? What in the hell do their spines look like?
Very interesting! Great find!!
I saw this the other day on one of those news magazine shows. Oh, what was it? I think it was Inside Edition. They even showed the callouses on their hands from walking that way. Apparently, also, from what I saw of it, they are all four pretty profoundly mentally retarded.
On another note, is any one else as bothered as I am by this "missing link" crap? The evolution of humans, ants, birds, fish, cats, and dogs is a continuum. The idea that there is a SPECIFIC point at which each point of evolution occured seems absurd to me.
It's like trying to pinpoint the exact point in time that your child grasps the english (or spanish, or german) language. Is it when they say their first word? Is it when they are able to understand when you speak to them? Is it when they can form complete sentences? Who knows?
It's a continuum.
Craziest story of they day!!
It is my opinion after reading more about this that these retarded children, now grown, were never taught to walk correctly. It takes some guidance and lots of patience. I think whatever scientists are looking for as far as human evolution goes is not going to be found in these people. I also agree that walking upright on two feet was a gradual evolutionary development over a period of time.
Walking upright, for hominids, was the result of a semi-aquatic lifestyle. The Aquatic Ape Hypothesis demonstrates that our earliest ancestors lived near and in marine environments for the following reasons;
Humans are unique among mammals in shedding heat by sweating. This costs salt - fatal for a savannah mammal, but not for one living close to water. It also provides a mechanism for shedding excess salt.
We alone among terrestrial mammals have descending larynxes, like whales, dolphins and seals - used only in order to take deep breaths to enable underwater diving.
We have subcutaneous fat bonded to the epidermis from beneath(blubber) - unusual amongst terrestrial mammals, but not among aquatic ones.
We are virtually hairless, and what hair we do have directs water to the centre-line.
Our offspring can be born underwater, with the instinctive ability to swim and curtail breathing - questionable for a savannah mammal, but not for an aquatic one.
As for walking upright, the act of wading into and out of water, along with the motion of swimming *in* the water, provide a neat explanation for the changes in pelvic structure and the lengthening / straightening of the lower limbs seen in adult humans (note that babies typically initially possess lower limbs still naturally bent at the knee).
Finally, the high in protein fish-diet suspected of accelerating hominid brain-growth 3-4 million years ago would be explained by a semi-aquatic lifestyle. Most early hominid remains are found near large bodies of water.
There endeth the lesson :o)
DC
DC - Interesting. Thanks for the science lesson. Do you have any suggested resources for learning more?
I remember a bit of this from Biology classes years ago, but along with that were theories that humans walked on their knuckles like gorillas for quite a long time. It wasn't just "a get out of the water and stand straight and walk" kind of thing.
Stardust 1954,
The Aquatic Ape Hypothesis is fairly well resourced on the internet, so any search engine should pop up some more in-depth research, along with the original papers from Brighton's Sub-Aqua Club presentation, which first publicised the hypothesis in the UK back in the 1950's.
Early hominids would indeed most likely have walked about much like chimpanzees before moving to more aquatic environments. The question is why they moved in the first place. Most researchers point to the fact that the majority of predators in Africa (big cats) aren't keen on water. Detractors mention that crocodiles, obviously, are.
At the time, there wasn't one species of hominid in Africa, but upwards of 20 or so, all competing with one another. The so called 'Missing Link' quite literally does not exist - our evolutionary tree is more like a bush than a single branch of progressive advancement. Some would have remained predominantly on land, others in the trees and so on...
DC
DC - I will be doing some researching and a lot of reading on this subject. I think this is an area where supporters of evolution need to become more educated to defend our stance and to be able to argue our position in a more informed manner.
Once I gather some information I will write a new post about what I find. Thanks again for getting my "wheels turning" on this.
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