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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