Posted on 07/19/2009 7:46:56 PM PDT by djf
Research by a group of Montreal scientists calls into question one of the most basic assumptions of human genetics: that when it comes to DNA, every cell in the body is essentially identical to every other cell. Their results appear in the July issue of the journal Human Mutation.
This discovery may undercut the rationale behind numerous large-scale genetic studies conducted over the last 15 years, studies which were supposed to isolate the causes of scores of human diseases.
(Excerpt) Read more at sciencedaily.com ...
Ditto on the ping, G3 - please.
We sought to examine the role of genetics in the multifactorial disease, abdominal aortic aneurysm (AAA), by studying sequence variation in the BAK1 gene (BAK1) that codes for an apoptotic-promoting protein, as chronic apoptosis activation has been linked to AAA development and progression. BAK1 abdominal aorta cDNA from AAA patients and nondiseased individuals were compared with each other, as well as to the BAK1 genomic sequence obtained from matching blood samples. We found specific BAK1 single nucleotide polymorphism (SNP) containing alleles in both aneurysmic (31 cases) and healthy aortic tissue (5 cases) without seeing them in the matching blood samples. These same BAK1 SNPs have been reported, although rarely (average frequency <0.06%), in reference BAK1 DNA sequences. Based on this and other similar observations, we propose a novel hypothesis postulating that multiple variants of genes may preexist in "minority" forms within specific nondiseased tissues and be selected for, when intra- and/or extracellular conditions change. Therefore, the fact that different BAK1 variants can exist in both diseased and nondiseased AA tissues compared to matching blood samples, together with the rare occurrence of these same SNPs in reference sequences, suggests that selection may be a significant factor in AAA ontogeny. (c) 2009 Wiley-Liss, Inc.It's no surprise that there could be SNPs in certain tissues and not in others. SNPs can arise both in germ and non-germ lines. Those in non-germ lines, though, will not be inherited.
Interesting...and obvious, if I had bothered to think about it. But what would the fun be in, if I actually *read* the article? :-)
Next annoying question, of course.
When one does tests on DNA samples for DNA clock testing, how do we know how much of the variation is from mutations passed on through germ lines, vs. individual variation within an individual animal?
Is the effect of individual variation likely to increase the error bars in estimations, or is it a minor factor at most?
Cheers!
I don’t think it would be presumptuous at all. Sounds like an excellent conclusion.
I do note, however, that the reason for the failure of the HGP, is going to have to have to (sadly, to some) be put in the realm of a philosophical context, something evos resist like oil resists water.
It’s been a ;omg time since I read it, but I thinkthey use a consensus sequence, that is they don’t just compare one DNA sequence of say actin, for example. They look at ,any published actin sequences for a specific animal, Human. Chimp, Cow, Pig,Fish,and geta consensus for each base. I remember actin is highly conserved since it is a vital protein for the organism.
With Rosen, it can also be seen in a mathematical context. Perhaps they will not be as biased towards Rosen...(crossing fingers.)
[[a) Complexity. We need distributed supercomputers to model protein folding, but the body does it on the fly in real time.]]
I’m too tired right now- not htinking well, but I think this really needs to be explored more deeply, as this complexity it seems to me would have had to been inplace BEFORE any supposed evolution could occure were it even possible. Macroevolutionists severely downplay the massive complexity, and just assume nature somehow was capable of creating such massive complexity out of what? Simple chemical configurations? Where did the information come from? Where did the metainformation that controls all the complex informaiton come from? IF ‘simple’ protein folding is so com-plex that supercomputers can’t even mimick the process, then how on earth could billions of other equally complex micro-biological systems just evovle via mutaiton to hte point where the millions of complex systems al lwork flawlessly together without any metainfo inplace to begin with?
I don’t htink peopel appreciate just how complex and intertwined millions of equally complex microbiological systems really are or even question how they could have slowly evolved while complex systems somehow managed to remain fit while al lthese massive changes were supposedly taking place
“With Rosen, it can also be seen in a mathematical context. Perhaps they will not be as biased towards Rosen...(crossing fingers.) “
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I dunno. An evo just the other day commented that math is not science.
http://www.freerepublic.com/focus/news/2295516/posts?page=232#232
“Thus demonstrating (once again) that mathematics is not science. “
Again, mathematics is not science. It is a method used to understand data.
Which is an understandable bias .... but also one that is highly unscientific in and of itself.
Consider: scientists convey a great deal of information and express complex ideas symbolically. They almost certainly do this without thinking about exactly what they're actually doing.
Because this symbolic communication conveys actual meaning (i.e., information that can reliably guide subsequent actions), there is clearly an empirical aspect to it, even if there is a certain intractability involved in trying to characterize the process of communication mathematically or otherwise.
The problem, of course, is that the language and symbols are meaningless without a priori agreement between the one expressing the ideas, and the one receiving them, as to the meaning of the symbols themselves, and also some common ground on the concepts being conveyed.
The existence and use of textbooks may shed some light on the process: the standard approach is for the author to build on prior knowledge to introduce new concepts and ways of describing and/or using them. To be able to convey new information, the author must first establish with his reader a prior common ground of concepts and symbols. The reader counts on the author to provide clear direction; the author expects the reader to be able to follow his line of thought to the point of being able to expand his grasp of the concepts involved.
The intractability of describing (mathematically) the thought processes of both the author and the reader is why this sort of discussion has generally been relegated to the realm of "mere" philosophy.
What's truly ironic is that empiricists should dismiss this topic as mere philosophy, given that it represents a stark failure of our current scientific/mathematical processes to explain what's going on. In the case of trying to understand DNA (for example), such an attitude is nothing less than surrender.
It sounds like Rosen is trying to address the gap ... I might have to look into what he's up to.
But the surest things we can say about the physical world are mathematical.
And mathematics is unreasonably effective in the natural sciences (Wigner) - I consider that phenomenon to be like God's copyright notice on the cosmos.
Precious few scientific theories achieve the status of a physical law. Compare that to mathematical proofs.
Mathematics is universal per se. The very existence of a variable in a formula testifies to the formula's universality.
While it's true that mathematics is not science, you are quite incorrect to characterize it as just "a method used to understand data."
That characterization completely misses the highly effective predictive power of mathematics -- Einstein's theories of relativity, for example, were first described mathematically, and the predictions were only much later and with great difficulty verified through experiment.
But sadly the empiricist often ignores anything which is not physicochemical and thus excludes the mathematics of communication on principle even though DNA demands it.
If you don’t mind, I’m going to put you on my Creation Ping list until I post the paper so I remember to ping you. Once I post it, probably tomorrow or the next day, just ping me to pull you off the list.
All the best—GGG
That goes without saying :o)
The research at the 'Models of Life' Basic Research Center at the Niels Bohr Institute has shown that communication between nucleosomes and positive feedback are likely to constitute fundamental memory mechanisms in individual cells. The mechanism gives both stability and openness to new influences which the cell could need to change state. Nature has a partner which controls the cells latent memory.
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