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IOW, the assumed timeclock in mtDNA mutation rates turned out to be wrong, or to put it another way, mtDNA stability is much greater than previously assumed. Thanks GonzoII.

More approaches have been brought to bear on the emergence and outgrowth of Homo sapiens sapiens (i.e., modern humans) than any other species including full genome sequence analysis of thousands of individuals and tens of thousands of mitochondria, paleontology, anthropology, history and linguistics [61, 142-144]. The congruence of these fields supports the view that modern human mitochondria and Y chromosome originated from conditions that imposed a single sequence on these genetic elements between 100,000 and 200,000 years ago [145-147]. Contemporary sequence data cannot tell whether mitochondrial and Y chromosomes clonality occurred at the same time, i.e., consistent with the extreme bottleneck of a founding pair, or via sorting within a founding population of thousands that was stable for tens of thousands of years [116]. As Kuhn points out unresolvable arguments tend toward rhetoric.Summary and conclusionScience greedily seizes simplicity among complexities. Speciation occurs via alternative pathways distinct in terms of the number of genes involved and the abruptness of transitions [148]. Nuclear variance in modern humans varies by loci in part due to unequal selection [149] and the linkage of neutral sites to those that undergo differential selection. Complexity is the norm when dealing with variance of the nuclear ensemble [150-154]. It is remarkable that despite the diversity of speciation mechanisms and pathways the mitochondrial sequence variance in almost all extant animal species should be constrained within narrow parameters. Mostly synonymous and apparently neutral variation in mitochondria within species shows a similar quantitative pattern across the entire animal kingdom. The pattern is that that most -- over 90% in the best characterized groups -- of the approximately five million barcode sequences cluster into groups with between 0.0% and 0.5% variance as measured by APD, with an average APD of 0.2%. Modern humans are a low-average animal species in terms of the APD. The molecular clock as a heuristic marks 1% sequence divergence per million years which is consistent with evidence for a clonal stage of human mitochondria between 100,000- 200,000 years ago and the 0.1% APD found in the modern human population [34, 155, 156]. A conjunction of factors could bring about the same result. However, one should not as a first impulse seek a complex and multifaceted explanation for one of the clearest, most data rich and general facts in all of evolution. The simple hypothesis is that the same explanation offered for the sequence variation found among modern humans applies equally to the modern populations of essentially all other animal species. Namely that the extant population, no matter what its current size or similarity to fossils of any age, has expanded from mitochondrial uniformity within the past 200,000 years.Mark Stoeckle and David S Thaler, Why should mitochondria define species?

Of course, the real headline should be, the Earth isn't 6000 years old. :^) To say that the paper currently under discussion (using that term loosely) is an outlier is something of an understatement. At best it could lead to an examination of the basis for the molecular clocks used to estimate dates for mitochondrial DNA mutation branching.

Ancient Greenland was actually green! [07/05/2007]
...sometime between 450,000 and 800,000 years ago, much of Greenland was especially green and covered in a boreal forest that was home to alder, spruce and pine trees, as well as insects such as butterflies and beetles.
Fossil DNA Proves Greenland Once Had Lush Forests; Ice Sheet Is Surprisingly Stable [07/05/2007]
Ancient Greenland was... covered in conifer forest and, like southern Sweden today, had a relatively mild climate. Eske Willerslev, a professor at Copenhagen University, has analysed the world's oldest DNA, preserved under the kilometre-thick icecap. The DNA is likely close to half a million years old, and the research is painting a picture which is overturning all previous assumptions about biological life and the climate in Greenland... large parts of Greenland were covered by forest. This was discovered by analysing fossil DNA which had been preserved under the kilometre-thick icecap. The DNA-traces are likely close to 450,000 years old, and that means that Greenland was also covered in a large ice sheet 125,000 years ago during the earth's last warm period, Eem. This was while the climate was 5 degrees warmer than the interglacial period we currently live in... Several projects... have been drilling through the icecap on Greenland, and collected complete columns of ice all the way from the top to the bottom. The ice has annual layers and is a frozen archive of the world's climate... Eske Willerslev, who is the world's leading expert in extracting DNA from organisms buried in permafrost.... "We have found grain, pine, yew and alder. These correspond to the landscapes we find in Eastern Canada and in the Swedish forests today. The trees provide a backdrop from which we can also ascertain the climate since each species has its own temperature requirements. The yew trees reveal that the temperature during the winter could not have been lower than minus 17 degrees Celsius, and the presence of other trees shows that summer temperatures were at least 10 degrees"... Furthermore Willerslev found genetic traces of insects such as butterflies, moths, flies and beetles... He analysed the insects' mitochondria, which are special genomes that change with time and like a clock can be used to date the DNA. He also analysed their amino acids which also change over time. Both datings showed that the insects were at least 450,000 years old... radioactive dating. "We can fix when the ice was last in contact with the atmosphere," says Jørgen Peder Steffensen... the special isotopes, Beryllium-10 and Chlorine-36 both have a particular half-life of radioactive decay... The relation between them can date when the ice and dust were buried and no longer came in contact with the atmosphere. The dating of dust particles also showed that it has been at least 450,000 years ago... That signifies that there was ice there during the Eemian interglacial period 125,000 years ago. It means that although we are now confronted with global warming, the whole ice sheet will not melt and bring about the tremendous sea-level rises...
Greenland Ice Core Analysis Shows Drastic Climate Change Near End Of Last Ice Age [06/19/2008]
The ice core showed the Northern Hemisphere briefly emerged from the last ice age some 14,700 years ago with a 22-degree-Fahrenheit spike in just 50 years, then plunged back into icy conditions before abruptly warming again about 11,700 years ago.
The big picture: 65 million years of temperature swings [02/26/2010]