Sorry, this is a copy from the BBC science news, but it seems worthwhile to direct your attention to this discussable topic. Could it be that first we walked like those children on palms with fingers free, and then later, as we found more use for fingers, progressively abandoned the walking on all four? It seems quite an interesting proposal that such use of hands could have been a transitional stage what later resulted in bipedal movement. http://news.bbc.co.uk/2/hi/science/nature/4782492.stm Read more at BBC
It says the reason that the children walk in such a way is due to brain damage, the part of the brain being damaged was that responsible for co-ordination. It's likely they walk that way because they can't co-ordinate themselves properly or balance efficiently enough to walk bi-pedally so they go down onto all fours. Next, that would be an interesting theory, as we kept our fingers free to do more delicate jobs. Wouldn't it have been the other way to you saying though? Surely they would have found use for their fingers and then adapted to move in such a way as to save them. Rather than saving the fingers, and Then using them.
The thing that more than one child has been born as such suggests that genetics are to blame. It's not a damaged brain per se, it's just not a normal brain. And genetic mutations certainly have some relation to evolution. As for me, I have no side in this argument, I'm not a scientist and don't have the data those guys have. It might well have been so, I agree with you. That is a lot more likely than what I had proposed.
I think it is probably bullshit. Can these people walk up straight at all? Chimps can... I think someone saw an opportunity to get some publicity and ran away with it.
Yea, if you read the full article, then two (I think) of those children can walk on two for short periods. You're a biologist, have anything to say about conditions such as these? Please Register or Log in to view the hidden image! Entirely possible. ---------- Two of the sisters and one brother have only ever walked on two hands and two feet, but another sister and brother can occasionally walk on two feet for a short time. They're making a full BBC program for this case, so it all can't be full of hot air. It seems that both sides of the argument are covered equally well.
I was led to believe that the transition from a quadrupedal gait to bipedal gait was characterized by some sort of transitional forms or characteristics in human evolution. I seriously doubt that we see some kind of genetic reversal to an ancestral state. Especially if the defect is located in the brain. Most adaptations seemed to occur in the structure of specific bones and musculature. At least that would be my first thought. 'Professor Humphrey thinks that the brain abnormality simply caused the siblings to rediscover a form of locomotion used by our ancestors.' When I read something like this my brain says: crackpot. We needed to develop a function in the brain to walk upright? I would hardly think so. I would need to see the real data, and then study human evolution for a few months to make a proper assessment. Which is impossible.
This report has been floating around the internet and the general media for a few weeks now. This is the third thread on Sciforums on it. Unfortunately, not many people seem to realize that it’s very poor science and not worthy of any serious consideration. I realize that “published” and “peer-reviewed” data is often held up in science forums (indeed, in the science field itself) as the benchmark for the validity of evidence, but nonetheless you have to be careful. Not all “published peer-reviewed” data is worthy of consideration. This is a good case in point. This paper in question regarding this supposed “reverse evolution” was published in the International Journal of Neuroscience. That sounds impressive but a little investigation reveals that this journal is ranked 175th out of 198 journals in the field of neuroscience with an impact factor of 0.579. The ‘impact factor’ is a weighted score that indicates how many times articles in the journal are referenced by other papers in other journals, thus providing an indication of the relevance and significance of the journal’s content. Its score 0.579 is very low. So the takehome message is this – people can publish poor quality research in this journal that would otherwise not be accepted in other higher-quality journals. This is immediately obvious when you actually read through the paper in question. (It is available free of charge from the journal website.) The fact that he is editor of this very journal is somewhat suspicious! The author has concluded that this is a new syndrome resulting from an autosomal recessive allele. Whilst it is true that the number of offspring with the phenotype (5 in 19) is suggestive of an autosomal recessive phenotype, as a geneticist I can say that there is no way you can conclude this from a single cross (ie. in this case, the progeny from a single pair of parents). You need multiple crosses across multiple generations, and in-crossing and back-crossing (ie. sibling-sibling and parent-sibling crosses) before you can confidently conclude the Mendelian inheritance pattern of any given phenotype. The author has no such data and thus, in the absence of <I><B>any</B></I> genetic data other than a single cross, it is erroneous to conclude that this represents a new syndrome. From the extremely limited data it’s just as likely that the cause is environmental rather than congenital. He states that there were MRI and CT scans performed but no figures were included. Why not? The bulk of the paper was taken up with an analysis of their gait and mental abilities. Numerous parallels were drawn with other animals but no references were included to substantiate any of the comparisons. The conclusion was that the five people in question have a “…quadrupedal palm-gait, severe mental retardation, primitive speech, and disturbed conscious experience.” Okay, fair enough. That statement of findings is not very debatable from the data. It’s the wild and unsubstantiated conclusions the author subsequently draws from these simple findings that make this whole paper a complete joke. There is only a single reference for the entire paper and it appears to relate to the brain structure and cognitive analysis that was performed. There are no references at all to substantiate any of his numerous evolutionary musings in the introduction and the discussion. From his physiological analysis of a single family he starts speculating on the evolutionary coupling of gait, brain size, speech, intelligence and consciousness! Bollocks! There’s no concrete evidence that the phenotype is genetic in the first place, let alone has anything to do with the evolution of bipedal gait. Such evolution is bound to involve a number of genetic alterations, not just a single gene. In short, this is one of the worst published papers I have ever seen. I hope the mass media doesn’t give it too much publicity. Just I case there was any doubt, here are further examples of his unsubstantiated hand-waving from the paper….. Pffft! Please Register or Log in to view the hidden image! <P>
I thought that the transition to bipedal was due to primates who evolved from tree dwellers. Note that many (most/all?) modern tree dwelling primates have feet that are very similar to hands. It seems like an easy transition from a tree dweller with four hands to evolve into a bidped with two hands and two feet.
and after moving out in to the savanna, it helps to be standing tall. it might just save your primitive ass.
Indeed. The paper, however, appears to be suggesting that the difference between bi- and quadpedal gait, as well as cognitive ability and brain development, is all tied to a single autosomal recessive allele. And that the evolution of bipedal gait, brain development and cognitive ability can be “reversed” in a congenital syndrome caused by the presence of two mutant alleles of this single gene. As I said, complete bollocks! Please Register or Log in to view the hidden image! <P>
Thanks for your input, Hercules Rockefeller, I put too much trust in the BBC that it won't publish bollox, lear something new every day Please Register or Log in to view the hidden image!
In my opinion the BBC is one of the better mass-media sources of science. Their science reporters generally seem to report accurately and emphasize the salient aspects of a story. The problem with this story is that it has the air of scientific legitimacy as the report has been published in a peer-reviewed journal. But as I described above, sometimes this means very little, especially when the author is also the chief-editor of the journal. Also, there appears to be a BBC TV documentary on this Turkish family, so cross-promotion is clearly a factor in the decision of the online BBC News to run this story.<P>
Update: I re-read the BBC story and noticed a paragraph that escaped my oringnal reading. In my original post I stated that there was no concrete evidence that this was a genetic trait. Certainly no such evidence was presented in the published paper other than the circumstantial observation that the phenotype was roughly similar in all 5 children with the phenotype and that the distribution of the phenotype (5 in 19) matches that of a recessive allele. The paper concentrated solely on physiological testing with no genetic/molecular analysis. But the BBC online report seems to indicate that, subsequently, some researchers have looked for a genetic component and have found a putative causative gene on chromosome 17. This may or may not turn out to be accurate, but at least it provides some more evidence that there is a genetic component to this co-called syndrome. However, even if the gene is identified, this does not validate the hand-waving on the part of the scientists that this gene is somehow solely responsible for the complex transition from quad- to bipedal posture as well as being important for brain development, size and cognitive ability. Trying to argue that it plays a fundamental role in bipedal evolution and the development of cognitive ability (as was argued in the paper) is still ludicrous. ‘nuff said.<P>
Crackpot indeed. I would not be surprised if he commented in the case of that 2 legged dog* that he luckly had a mutation for bipedal gaiting-brain prior to the accident that make him lose the two legs. I'm afraid creationists will eventually make publicity of that as the "piltdown family" or something. * a dog that lose two of his legs, both right or left, but was still able to run and locomove very effectively, in a manner that is almost unbelievable. If someones doesn't have a very clear vision might not even be suspicious that there's something wrong with the dog while seeing he at distance or by side. A video can be found in a site called "mass destraction", but I've found the link through the blog pharyngula.
What about the shape and/or orientation of the internal chambers of the ear? I understand that these are different in truly bipedal animals, or even partially bipedal animals like chimpanzees (or knuckle-walkers like gorillas.) If there truly is a genetic component in this case, as asserted in the article mentioned, is there evidence of a difference in the inner ear? On the other hand, if it's due merely to extreme mental retardation, could it be the equivelant of those people who've been brought up by wild animals (Lobo Girl or the wolf-children of India, for example) and have not learned to walk properly because bipedalism is the only example presented to them by their adoptive species? Please Register or Log in to view the hidden image!
The human skeletal structure is NOT designed for quadruped movement. If you attempted to emulate these people you would likely agree with this conclusion. It is a very difficult movement primarily because of the shape and structure of our pelvis and limbs (as Monkey eluded to before). These people will probably develop health problems as a consequence of their behavior.
I´ve just heard of, but apparently as more people were investigating the issue, turned out that they have some brain problem, affecting coordination. They´ve never even made physiotherapy before, now they´re using some supports to assist them in walking bipedally.
Horses and elephants can rear up and walk on their hind legs. Cats, bears, racoons, the list is endless. Dogs can do it very deftly and keep it up for a long time. Chimps and orangs can walk around like people. Apparently it's just not that difficult.
The origin of bipedal or quadraped animals goes far beyond what is said in this article: the origin lies in the fact that "symmetry" is an advantageous trait in all animals. Two fins help a fish swim straight. Two eyes help an organism see up to 360 degrees. Symmetrical features are what evolved eventually into bipedal and quadrepal feautures. So the fundamental question is: What genetic mutation persisted that led to this? And what environmental condition caused it to persist? I think it had to begin with the bilateral fins on fish because before that organisms were fin-less. Fish that evolved with a one-fin mutation couldn't survive, but those with two had the advantage: they could swim.
