Posted on 10/15/2007 10:45:59 AM PDT by blam
Source: Public Library of Science
Date: October 14, 2007
Inconsistencies With Neanderthal Genomic DNA Sequences
Science Daily Were Neanderthals direct ancestors of contemporary humans or an evolutionary side branch that eventually died out?
This is one of the enduring questions in human evolution as scientists explore the relationship of fossil groups, such as Neanderthals, with people alive today. Two recent papers describing the sequencing of Neanderthal nuclear DNA from fossil bone held promise for finally answering this question [1, 2].
However, the two studies came to very different conclusions regarding the ancestral role of Neanderthals. Jeffrey D. Wall and Sung K. Kim from University of California San Francisco now reveal in PLoS Genetics what they found when they reanalyzed the data from the two original studies.
Wall and Kim's reanalysis reveals inconsistencies between them and they believe that possible contamination with modern human DNA and/or a high rate of sequencing errors compromised the findings of one of the original Neanderthal DNA studies.
The authors therefore recommend that we carefully evaluate published and future data before arriving at any firm conclusions about human evolution.
References
1. Noonan JP, Coop G, Kudaravalli S, Smith D, Krause J, et al. (2006) Sequencing and analysis of Neanderthal genomic DNA. Science 314: 1113-1118.
2. Green RE, Krause J, Ptak SE, Briggs AW, Ronan MT, et al. (2006) Analysis of one million base pairs of Neanderthal DNA. Nature 16: 330-336.
Citation: Wall JD, Kim SK (2007) Inconsistencies in Neanderthal genomic DNA sequences. PLoS Genet 3(10): e175. doi:10.1371/journal.pgen.0030175
Or, more likely, are their descendants still here among us?
- ;o)
Here’s this, from Ars Technica:
By John Timmer | Published: October 15, 2007 - 10:33AM CT
About a year ago, we reported on the latest results in the sequencing of Neanderthal DNA, which had netted a million bases of the genome of our extinct relative. Those were just the first results of a sequencing effort that was planned to continue; there is probably about another 18 months worth of data that have accumulated since the writing of those papers had started. Unfortunately, an Open Access publication in PLoS Genetics suggests that at least some of the original results are artifacts, the result of human contamination.
The new analysis was triggered by differences in the methods and results in the two papers that were published on the topic. A paper in Science described cloning Neanderthal DNA in bacteria, and then sequencing it. The one in Nature sequenced amplified DNA directly. Although there was substantial agreement between the two, the Nature paper suggested that modern humans and Neanderthals shared a common ancestor more recently, and may have interbred after their separation.
The authors of the PLoS paper obtained the original sequence data from both papers, and performed a new analysis of it. They discovered that the data in the Nature paper contains sequence differences that appear to have arisen recently within the human lineage, which suggested something was wrong. Performing an estimation of the human-Neanderthal split date using the Nature data produced a value of 35,000 years, which is completely incompatible with the fossil record. Finally, using a date of 350,000 years for the split (obtained using the data from the Science paper), they found that the Nature data indicated extremely high levels of interbreeding between humans and Neanderthals; the Science data continued to suggest there was none.
All of these results point to one conclusion: the Neanderthal sequence in the Nature paper looks far more like that of modern humans than any other data would suggest is possible. Of course, there’s a simple and obvious explanation for that discrepancy: the sequence is from modern humans.
The new paper explores this via the following reasoning: ancient DNA is more likely to be damaged and fragmented, and so contamination is more likely to appear in longer, less damaged fragments. They divided the Nature sequence data according to the length into short, medium, and long pools. The short fragments give an age estimate for the Neanderthal-human split that’s essentially identical to the one obtained with the Science data. But, as the fragments get longer, the age shrinks. When fragments greater than 100 bases long are examined, they give an age estimate for the split that is younger than some splits within modern human populations. Thus, the longer fragments are very likely to be contamination from modern humans.
The authors recognize that more work needs to be done to sort out some remaining discrepancies, but the new analysis strongly suggests that a large portion of the original data was the result of contamination. We know less about the Neanderthals than we thought we did. Still, the analysis suggests that there is real Neanderthal sequence among the contaminants, and suggests a fairly simple analysis may help us extract it. It’s a great example of how science can self-correct.
Thank you Lol
If this stuff was easy, it would have been done years ago!
And it is not easy getting usable DNA from old bones. I recently submitted bone and teeth samples dating about 4800 and 5300 years ago. Three samples of bone at 4800 did not yield usable mtDNA, but the tooth at 5300 worked just fine.
The folks working the Neanderthal problem are to be commended, and I am sure that they will eventually solve the problem.
It's not as if they could look up the techniques in a book; they have to invent the methods as they go!
Good article.
“Or the results didnt match what they wanted to find.”
That’s usually the problem!
Thanks for the ping!
(A) ACROMEGALY.
Acromegaly, like oversized dentition, is a proper function of growth hormone at an improper time or in an abnormal amount. When acromegaly occurs in our age, it is the abnormal, but it may have been the normal in the earlier age. When it occurs in our age, the lower jaw begins to expand, becomes prognathous, and overrides the upper jaw. The dentition becomes more widely spaced. The posture sags as the clavicle thickens. The supraorbital ridges expand and the eyebrows protrude. The zygomatic arches thicken. The temporo-mandibular joint and cranium expand. The vertebrae thicken, as do the metacarpals and meta-tarsals (fingers and toes). In addition to skeletal changes, the hair coarsens, metabolism changes, and the psychology of the person may change although the intellectual powers may remain acute. The basic genetic material has not changed. There has been no transmutation of species, as Darwinians intuitively assert.
It very easily can be demonstrated that twentieth century men, possessing no apelike genes, may— due to a certain type of endocrine disorder—develop “apelike” characteristics in their skin, hair, metabolism, and skeletal system. This is known as acromegaly. Itis caused by the abnormal resumption of growth hormone after maturation. A reactivation of this particular function of the pituitary gland—the master gland—causes renewed bone growth. Since at maturation the epiphyses close (the bones fuse), they can no longer elongate and therefore must grow by thickening. The cause of acromegaly is not well understood, but malfunctions in pituitary tissues may be one cause. Today, this skeletal malformation occurs in about one person in 10,000, in males and females in equal ratios, and usually in persons in their twenties and thirties—about one or two decades after maturation.
The description of a person afflicted with acromegaly sounds like a description of Neanderthal Man, and the changes are not merely limited to skeletal malformations.
In the following excerpts from medical textbooks, there are similarities of the descriptions with Apemen. Since acromegaly is considered a basic physiological imbalance, it is medically classified as a retrogressive development. Here is a case which the medical profession describes as retrogression, a case strikingly similar to what Darwinists term evolution:
As in many endocrine types, there is considerable resemblance among all acromegalics. The large extremities, awkward movements, thickened features, and drooping shoulders with hands falling near the knees in advanced cases, give the picture of Simian (apelike) man, and where gigantism has preceded the acromegalic changes, of a primitive ape-like giant. Great strength, however, may give place to exhaustion and weakness in the later stages ...
The skull is considerably thickened, the ridges becoming very prominent, and the external occipital protuberance enlarged. The cranial sutures may be obliterated. Even more marked are the changes of the facial bones: thickening and enlargement of the zygomatic arches, of the malar bones, and especially of the lower jaw, which becomes prognathous through overgrowth and also through changes in the temporo-manibular joint. The teeth become spaced wide apart as the jaw increases in width. The clavicles are thickened, and the antero-posterior diameter of the chest is greatly increased...20
The patient with fully developed disease presents a striking appearance which, when once seen, is never forgotten. The hands become large due to a broadening and thickening of the fingers and palms, so that they assume a “spade-like” appearance. They feel stiff and clench with some difficulty. The facial features coarsen, the lips thicken, while the nose becomes large and bulbous. The head increases in size and the supraorbital ridges become prominent and overhanging. There occurs a protrusion of the lower jaw, the so-called “prognathism,” due essentially to thickening and overgrowth of the mandible. As a result, the teeth become widely spaced and override the upper dentition . . . The patients frequently stoop due to kyphosis associated with enlargement and thickening of the vertebrae . . . They are sullen and vacillating, although mentally quite alert and normally endowed.21
Post-Darwinian evolutionists have assumed and taught that Neanderthal proportions are due to some admixture or transmutation of apelike genes. They have further assumed and taught that these proportions, formed by some transmuted ape genes, have been modified by some as yet unascertained biochemical mechanism. But Neanderthal Man is an excellent parallel to the modern description of acromegaly.22
http://www.creationism.org/patten/PattenBiblFlood/PattenBiblFlood10.htm
That behavior makes even the Helen Thomas pictures look respectable.
lol- since hwne is Acromegally ‘anti-science’? It would seem that ignoring hte obvious implications of skulls that carry acromegally traits would be antiscience’ - but meh- suggesting that one do a thorough investigation even if it doesn’t fit hte dogma of evolution is apparently ‘antiscience’ lol You’re not by any chance suggesting ancient creatures didn’t have pituitarys and pit conditions are you?
It’s the GEICO effect; coming to the forefront.
"Go ahead; CALL me stupid - but I'VE got a Nobel, and YOU don't!"
[[Some interesting observations:
http://www.amazon.com/gp/product/0890512388/
Buried Alive: The Startling Truth About Neanderthal Man
by Jack Cuozzo]]
Lol- just readuing htrough the ‘reviews’ on Amazon oif hte book- same old same old- Ad hominem attacks aghainst hte writer with no solid refutaitons of hte facts presetned at all- Typical sadly
LOL!
Following the leads on that book led me to talkorigins where they present ‘rebuttles’ to Cuzzo, and leave their readers htinking that Cuzzo’s finds have been discreditted- yet, following furhgter, you get to Cuzzo’s site, and read his responses to the articles listed on TalkOrigin, and find out that the reubttles break down under close careful examination, and the ‘rocks’ tha6t Chris Stringer claimed hte bones to be are infact NOT rocks but actual bone- just as Cuzzo said they were, yet for some reason (wink wink- nod nod (sins of ommission)) TalkOrigins neglects to post htis for a fair and objective evaluation on their site- Again- sadly, this is typical of the ‘real science’ that evos keep referring to - objectivity and dispassionate examination of hte evidences be damned evidently (but this is hte ‘real science’ we’re told creationsits don’t understand)- anyway- thanks for htel ink- another fine example of ‘real science’ bullying.
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