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.
Here’s a simple truth to challenge your coping skills; people who make that kind of money don’t feel the need to brag about it on anonymous websites. Nor do they act like tattle-tale pre-pubescent little girls. Your behavior gives you away. I’m not buying your stories; futhermore, I highly doubt anyone else here believes them.
Why don’t you go back to KOS or DU and tell them how amazing you are. They might believe you. They too are addicted to make-believe fantasy worlds and crave acceptance.
It really makes no difference whether you believe me or not. If your rants make you feel better, fine, but think twice before calling others here on FR mouth-breathing half-wits. It only makes you look very little.
Not bragging. You hurled an intended insult. I set you straight with the facts.
If it made no difference, you wouldn't respond.
And how does it look to others that you are full of insults like calling other FRers 'mouth-breathing half-wits'?
And if you flapped your arms and flew off into a tree the argument would be that anyone can do bird imitations.
Good grief!!! How difficult can it be to understand that if the dating method is inaccurate then all that is drawn from the method is questionable.
So, if the Jonah in the whale story is false, then all that is in the Bible is questionable?
For example, if they had a penguins from 1,000, 10,000 and 100,000 years ago and compared them to the modern penguins you would find an increasing amount of difference as you go further and further back in time.
Based upon their analysis they claim that most estimates of date of common ancestry based on DNA comparison between two extant species WITHOUT a good fossil reference were underestimated.
If the time needed to derive the measured amount of divergence between a panda and a raccoon for example, is pushed back twice as far, that means that the rate of evolutionary change is half as fast as previously expected.
44,000 year old penguin bones? Impossible! The Earth is only six thousand years old.
You haven't digested this, because it supports the biblical creation model. If, for example, two populations differ by 10 nucleotides, and it was previous assumed that one nucleotide substitution took 1000 years, then we would have a divergence date of 10,000 years. But if actual rates of evolutionary change are measured at one substitution every 500 years, then the divergence date changes to 5,000 years.
This is one reason why creationists are pleased that scientists keep finding evidence for much more rapid change in evolutionary biology than evolutionists once supposed. The continual evolutionist refrain that creationists believe in stasis is a figment of their own imagination. It is not even remotely accurate, as even a cursory review of creationist literature shows.
But you believe in that silly story about Jonah and the whale because if it were false, your whole faith would crumble?
Clue. GGG is NOT an evolutionist. You are pinging to the clueless.
LOL!
ColdWater, how did you become such a hipocrit? You chastised me in your post #65 -
And how does it look to others that you are full of insults like calling other FRers 'mouth-breathing half-wits'?
Now you call GGG "Clueless!"
That's no way for a wealthy professional, pulling in three figures an hour, to behave!
Good morning. Thanks for reminding everyone that your favorite phrase for blindsiding other FRers is “mouth-breathing half-wit”
What you would need to demonstrate is that there are no genetic mutation and never have been any and each form of life, species, subspecies, etc. arises sui generis (created by god or whatever intelligent creator you posit in place of god) and is genetically stable for all time.
In short, your reasoning is circular.
All conclusions from all data, however accurate they are believed to be, are "questionable." It is not science that deals in religious certainties, but rather religious fundamentalists.
The epistemilogical conclusions from the fact that the dating method is alleged to be inaccurate, and that the dating method is illegitimate are wrong.
Let me try a simple reasoning by analysis. Suppose a village and surrounding farm area were surveyed in medieval times by a surveyor whose measuring device was ten percent short, but otherwise the surveys were flawlessly executed, with boundaries around the surveyed region clearly established, etc. Do we conclude that all property titles are invalid and the property now belongs to God, or do we simply realise the error; rescale the dimmensions on the landholdings to reflect the difference between the physical boundaries and the measured boundaries, and allow the farmers and homeowners to go about their lives in peace.
As a second example, it took many years to refine the measurements of the charge of an electron to its presently accepted value (within established error bars). That the charge was constantly adjusted through better and better measurement techniques did not disprove the underlying theory that the charge of an electron was unique, well defined, and indivisible.
This is logical twaddle and nonsense. If creationists believe that evolution happens faster than the generally acccepted rate based on previous biological data, and if creationists have new data to back up their conclusion that the dating methods need simply to be revised, then there is little argument between so-called "creationists" and "evolutionists," and you are suggeting the kind of "argument" that happens all of the time in science.
I think, however, that you fraudulently misrepresent the actual position taken by creationists, who normally deny that evolution takes place at all whatever the rate of evolution, and whatever the range of variability between place, time and species might be hypothesized.
BTW, Did you read the link I provided? Did you happen to notice the circular reasoning the evos based the mitochondrial clock on? Did you happen to notice the date range they gave to the mitochondrial eve once they recalibrated the mitochondrial clock based on empirically observed mutation rates?
Your ignorance of how science works is deplorable. Whoever turns out to be right in the dating scale argument, the point is that scientific theories are always constantly refined as better data becomes available. The theory of operation of the solid state devices in your computer have changed markedly since the PC was invented. PCs are not "invalid" or "useless" because the underlying theory of solid state physics has been modified and improved.
Since we only discovered how to sequence DNA reliably and economically starting in the mid 1980s a process that has improved rapidly in subsequent years, its application to biological study, archaeo-biology, paleontology, etc. is very very recent, and of course understanding is rapidly progressing, and conclusions changing.
That our understanding is being refined does not invalidate underlying techniques and premises, i.e. the theory that life evolves based upon genetic mutations and competitive selection for fitness in an environment.
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