Posted on 11/10/2009 10:54:53 AM PST by decimon
CORVALLIS, Ore. - Penguins that died 44,000 years ago in Antarctica have provided extraordinary frozen DNA samples that challenge the accuracy of traditional genetic aging measurements, and suggest those approaches have been routinely underestimating the age of many specimens by 200 to 600 percent.
In other words, a biological specimen determined by traditional DNA testing to be 100,000 years old may actually be 200,000 to 600,000 years old, researchers suggest in a new report in Trends in Genetics, a professional journal.
The findings raise doubts about the accuracy of many evolutionary rates based on conventional types of genetic analysis.
“Some earlier work based on small amounts of DNA indicated this same problem, but now we have more conclusive evidence based on the study of almost an entire mitochondrial genome,” said Dee Denver, an evolutionary biologist with the Center for Genome Research and Biocomputing at Oregon State University.
“The observations in this report appear to be fundamental and should extend to most animal species,” he added. “We believe that traditional DNA dating techniques are fundamentally flawed, and that the rates of evolution are in fact much faster than conventional technologies have led us to believe.”
The findings, researchers say, are primarily a challenge to the techniques used to determine the age of a sample by genetic analysis alone, rather than by other observations about fossils. In particular, they may force a widespread re-examination of determinations about when one species split off from another, if that determination was based largely on genetic evidence.
For years, researchers have been using their understanding of the rates of genetic mutations in cells to help date ancient biological samples, and in what’s called “phylogenetic comparison,” used that information along with fossil evidence to determine the dates of fossils and the history of evolution. The rates of molecular evolution “underpin much of modern evolutionary biology,” the researchers noted in their report.
“For the genetic analysis to be accurate, however, you must have the right molecular clock rate,” Denver said. “We now think that many genetic changes were happening that conventional DNA analysis did not capture. They were fairly easy to use and apply but also too indirect, and inaccurate as a result.”
This conclusion, researchers said, was forced by the study of many penguin bones that were well preserved by sub-freezing temperatures in Antarctica. These penguins live in massive rookeries, have inhabited the same areas for thousands of years, and it was comparatively simple to identify bones of different ages just by digging deeper in areas where they died and their bones piled up.
For their study, the scientists used a range of mitochondrial DNA found in bones ranging from 250 years to about 44,000 years old.
“In a temperate zone when an animal dies and falls to the ground, their DNA might degrade within a year,” Denver said. “In Antarctica the same remains are well-preserved for tens of thousands of years. It’s a remarkable scientific resource.”
A precise study of this ancient DNA was compared to the known ages of the bones, and produced results that were far different than conventional analysis would have suggested. Researchers also determined that different types of DNA sequences changed at different rates.
Aside from raising doubts about the accuracy of many specimens dated with conventional approaches, the study may give researchers tools to improve their future dating estimates, Denver said.
Collaborators on the research included scientists from OSU, Griffith University in Australia, the University of Auckland in New Zealand, Massey University in New Zealand, University of North Carolina in Wilmington, the Scripps Research Institute, and Universita’ di Pisa in Italy.
The studies were supported by the National Science Foundation, National Geographic Society, and other agencies. About the OSU College of Science: As one of the largest academic units at OSU, the College of Science has 14 departments and programs, 13 pre-professional programs, and provides the basic science courses essential to the education of every OSU student. Its faculty are international leaders in scientific research.
... to you - let it be emphasized. But that is not my point. I am not here to defend evolution, or the findings of molecular biology. I am here to show the complete and utter violation of the rules of logic and empiricism that are being followed by the critics of the theory of evolution.
The theory of evolution and the theories of genetics can be all wrong for all I care in this argument. I am not defending them. I am merely pointing out that the arguments mounted here against them do not pass muster.
In order to refute a hypothesis you need sound scientific data that all can review and argue about and some can reproduce. And your refutation cannot assume that what you are trying to refute is true, i.e. you cannot attack the theory of evolution on the basis that the rate of genetic mutation is wrong, unless you can demonstrate that the rate of mutation is effectively zero, and that is one thing that no one here as argued.
You cannot refute the Copernican hypothesis of a solar centric planetary system by arguing that, well, some of the predictions of comet orbits were wrong and their orbits around the sun are really different that what others had predicted. All the argument does is reaffirm what you set out to disprove, namely, that objects in the solar system are "in orbit around the sun," which, to be physically accurate, is a shorthand way of saying that they orbit around the center of mass of the solar system which is effectively located at the sun. Even finding retrograde comets affirms the original hypothesis.
That a hypothesis is refined and corrected as the result of more data and better thought is not a disproof of the scientific method, or demonstration that scientists are liars, but rather the opposite, that they are seeking the right answer as best they can.
But a whole scenario is based upon a mtDNA “Eve”. Logic would seem to require questioning the assumptions involved. "That a hypothesis is refined and corrected as the result of more data and better thought is not a disproof of the scientific method, or demonstration that scientists are liars, but rather the opposite, that they are seeking the right answer as best they can." Yeah, poorly framed arguments neither prove or disprove anything. However this isn't what the article was about, rather the fundamentals of an argument being in error. What fundamental ideas of Copernicus' could be in error without calling into question his hypothesis?
You would say that Newton’s laws of gravitation should be thrown out because Einstein found it inadequate.
You would say that Einstein’s Universal law of Space-Gravity should be thrown out because it in not entirely universal.
But then you say "Ive always maintained all humans came from a samll number (2) of individuals," which means one female, and voila, your biblical theory is consistent with the genetic theory.
What is the assumption involved in the "eve" theory? The scientific observation that all non African mtDNA appears to be a mutation from a common ancestor, while there is a wider diversity in Africa. This is the source of the hypothesis that an "Eve" existed and the further hypothesis that "Eve" came from Africa.
Of course scientists question these hypotheses, and the observations that underlie them. But a mistake in the rate of mutations does not change the observation of the lack of mtDNA diversity in non African populations, which is an observation independent of the rate.
You seem to want the admin moderator's intervention. Perhaps instead I should ping Jim Robinson. But that's not necessary; he often reads these Crevo threads, looking for trolls...
I'll lay it all out in sequence. I hope you can follow the linear time line which is used by those of us who enjoy normal brain function. If necessary, you should ask your physician to up your meds.
My first post was post #44 in response to post #8. At that time I had not read any further than post #8. I hadn't seen hitchit's post (#10) until after posting my comment; remember, I posted to #8 before scrolling any further. This means I could not have seen post #10 until after posting #44. Whew!
Post #45 was your post telling me "You Lose." Again, post #45 was your post, not my post. Try to keep the facts straight in spite of the drug induced haze.
I posted #46 with a link to post #10 and the words, "guess again."
After your feeble attempt to chastise me for calling someone a half-wit; you have not yet responded to me after I called you out for referring to another FReeper (GGG) as "Clueless." Furthermore, you failed to include GGG when you posted your insult. You are a hypocrite.
I would wager you are also a bed wetter who likes to play with matches and your Mother is concerned that you might burn the house down and you will never progress beyond the position of "French-Fry boy" at the local fast food joint. However, that is merely speculation on my part. By the way, please spend more time outside of your Mother's basement. It would make her happy.
I'm not sure what your problem is, but I'm sure it's hard to pronounce and a pharmaceutical company makes a chemical to treat it.
Incidentally, I haven't seen hitchit (note the correct spelling) weigh in on this. How did it become your problem? Is trolling vicariously on the behalf of others part of your obsessive compulsive disorder?
You lose.
That's what I said. After saying there would be some 'mouth-breathing half-wit' posting, you pointed to #10 as an example of a 'mouth-breathing half-wit'. Glad to see you finally own up to it.
Ronald Reagan once said (paraphrased): A Socialist is someone who read Karl Marx; a Capitalist is one who understands Karl Marx.
Just remember, you can cure ignorance; stupidity is incurable.
I guess I will have to use military time ....
Post #10: 1220 Nov. 10
Post #44: 2127 Nov. 10
That means you had 9 hours and 7 minutes to have seen #10 BEFORE posting #44.
Hey Chuckles, I stated what happened because I operate in the realm of reality while you wallow in your disassociation disorders. Have you been sitting at your computer all this time? Damn, get a life!
When are you going to own up to doing what you accused me of?
Come on you impotent hypocrit. You called GGG clueless while failing to include him in your post. Are you above your own rules, Mr Nancy Pelosi?
Uh, when you posted to me you pointed out his post. You brought him into this, not me. If you had given him a courtesy ping ....
I sat down to catch a few minutes of the Phoenix game and dang, there you were!
Post #10: 1220 Nov. 10
Post #44: 2127 Nov. 10
Put the crack pipe down and read my post again. AS I stated earlier, I read from the beginning and then I stopped at post #8 and posted my first post on this thread. Then I continued reading.
For the love of God and all that's Holy, I pray that you haven't found a woman as equally demented as yourself and spawned any more versions of yourself. Your lack of reading comprehension tags you as a genetic dead end.
It might help if you read a complete post before responding. That's behavior typical of those who earn three or more figures per hour.
Oh. You and JR are tight?
I did read the complete post before responding.
I forgot. Did I accuse you of anything? I stated a fact that you referred to H as a 'mouth-breathing half-wit'.
Nope, and I won't claim it either. As I stated earlier, some of us are grounded in reality while others (like you) are lost in delusions or desparate needs to impress others on an anonymous message board.
If you possessed basic reading comprehension and you read the entire post, You would understand that Jim Robinson often reads Crevo threads and slams trolls.
I can see from the above that you are not even remotely close to JR and know nothing of what JR is trying to accomplish.
It was sarcasm.
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