Tuesday, February 26, 2013

A Second, Closer Look at DNA – Part III – The Problems With DNA “Science”--The Demise of Mitochrondrial Eve

Continuing from the last post, it was not forbidden fruit in the Garden of Eden that caused mitochondrial Eve’s demise this time around.  The “passing” of one of evolution’s most familiar icons is due to new scientific facts that have surfaced since her introduction in 1987. If humans received mitochondrial DNA only from their mothers, then researchers could “map” a family tree using that information.  And, if the mutations affecting MtDNA had indeed occurred at constant rates, then the MtDNA could serve as a molecular clock for timing evolutionary events and reconstructing the evolutionary history of extant species. 
It is the “ifs” in these two sentences that are the problem.
Note the built in time of the molecular clock, with divisions every 25 million years, which promotes older ages in the process
Another study that was published in 2002 pointed out a built-in, natural bias for older ages that result from use of the molecular clock.  The researchers who carried out the study noted: “There is presently a conflict between fossil- and molecular-based evolutionary time scales.  Molecular approaches for dating the branches of the tree of life frequently lead to substantially deeper (older) times of divergence than those inferred by paleontologists. Here we show that molecular time estimates suffer from a methodological handicap, namely that they are asymmetrically bounded random variables, constrained by a nonelastic boundary at the lower end, but not at the higher end of the distribution.”
Big surprise, right?
As Francisco Rodriguez-Trelles went on to add, “This introduces a bias toward an overestimation of time since divergence, which becomes greater as the length of the molecular sequence and the rate of evolution decrease.  Despite the booming amount of sequence information, molecular timing of evolutionary events has continued to yield conspicuously deeper dates than indicated by the stratigraphic data.  Increasingly, the discrepancies between molecular and paleontological estimates are ascribed to deficiencies of the fossil record, while sequence-based time-tables gain credit.  Yet, we have identified a fundamental flaw of molecular dating methods, which leads to dates that are systematically biased towards substantial overestimation of evolutionary times.”
LtoR: Thomas J. Parsons, Ann Gibbons, David S. Muniec
Until approximately 1997, we did not have good empirical measures of mutation rates in humans.  However, that situation greatly improved when geneticists were able to analyze DNA from individuals with well-established family trees going back several generations.  One study led by Thomas J. Parsons and David S. Muniec of the Armed Forces DNA Identification Laboratory, found that mutation rates in mitochondrial DNA were eighteen times higher than previous estimates.
Science writer Ann Gibbons authored an article for the January 2, 1998 issue of Science titled “Calibrating the Mitochondrial Clock,” the subheading of which reads: “Mitochondrial DNA appears to mutate much faster than expected, prompting new DNA forensics procedures and raising troubling questions about the dating of evolutionary events.” In that article, she discussed the new data which showed that the mutation rates used to obtain mitochondrial Eve’s age no longer could be considered valid, and added,  “Regardless of the cause, evolutionists are most concerned about the effect of a faster mutation rate.  For example, researchers have calculated that “mitochondrial Eve”—the woman whose MtDNA was ancestral to that in all living people—lived 100,000 to 200,000 years ago in Africa. Using the new clock, she would be a mere 6,000 years old.”
6,000 years old! Does that time sound familiar to anyone?
Gibbons quickly went on to note, of course, that “no one thinks that’s the case.”
Naturally, no one in the scientific community is going to talk about an earth, or a descendancy less than hundreds of thousasnds of years; however, the point is that evidence shows a 6,000 year old tree, not 100,000 to 200,000 years. As Gibbons concluded with the fact that many test results are (to use her exact word) “inconclusive.” She then noted: “And, for now, so are some of the evolutionary results gained by using the MtDNA clock.”
We now know that the two key assumptions behind the data used to establish the existence of “mitochondrial Eve” are not just flawed, but wrong. That is, the assumption that mitochondrial DNA is passed down only by the mother is completely incorrect (it also can be passed on by the father).  And, the mutation rates used to calibrate the so-called “molecular clock” are now known to have been in error.  (To use the words of Rodriguez-Trelles and his coworkers, the method contains a “fundamental flaw.”)
With the early results, Philip Awadalla (left) the University of Montreal researcher was able to study the rate of mutation of human DNA in a generation. "For the first time, we had access to the complete sequences of the DNA of two couples and their children. Developing appropriate computer algorithms, we were able to compare the billions of base pairs to see where the differences were”
Philip Awadalla and his coworkers noted in Science (1999 Vol 286, p2525): “Many inferences about the pattern and tempo of human evolution and MtDNA evolution have been based on the assumption of clonal inheritance.  There inferences will now have to be reconsidered.” However, rather than merely “reconsidering” their theory and attempting to revamp it accordingly, evolutionists need to admit, honestly and forthrightly, that “mitochondrial Eve,” as it turns out, has existed only in their minds, not in the facts of the real world. 
Science works by analyzing the data and forming hypotheses based on those data.  Science is not supposed to massage the data until they fit a certain preconceived hypothesis. All of the conclusions that have been drawn from research on mitochondrial Eve via the molecular clock must now be discarded as unreliable.  A funeral and interment are in order for mitochondrial Eve.
Like so many things in science—what is earth-shattering news of a new paradigm one day is rescinded the next, and a new paradigm established in its place. That is, all those who have been assigning locations for DNA, figuring clans, groups, geographical locations, and genealogical ancestry, need to take another look at what they have been touting since DNA is an ever-changing process and is quickly being adjusted with each new discovery.
One thing is for certain. DNA has not advanced far enough for anyone to make a serious claim that Western Hemisphere ancestry is known and understood today through DNA testing and research!

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