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Just how reliable 'is' DNA?

Posted: Mon Aug 04, 2008 12:21 am
by _Mahonri
In testing Western Hemisphere and South Sea brown skinned types and finding no 'hebrew' DNA, how reliable is this testing? Can they really go back and find out what one is made up of a few generations back without knowing family history or family trees?
Any actual testing of families where lineage is know for generations? (other than the black sheep/mistresses/etc) to show this stuff is accurate? Or is it scientific flim-flam that can show whaever one wants to make of its testing results?

Posted: Mon Aug 04, 2008 12:52 am
by _Thama
It isn't as tremendously reliable, say, as the sort of DNA testing used in forsenics -- that sort of analysis gives, when performed correctly, astronomical odds of being incorrect. It is, however, plenty reliable to use as a basis for archaeological theories.

All experiments and studies are vulnerable to the biases of a undisciplined or dishonest researcher. This is why peer review is so important.

Posted: Mon Aug 04, 2008 1:17 am
by _The Dude
Hi Mahonri,

For populations like the Native Americans, DNA evidence is pretty reliable but it has a limited scope. Claims are often misstated by those who don't understand how to interpret the studies and phrase the conclusions accurately. For example, an accurate statement about Native American DNA cannot include the words "Hebrew DNA" since there's no such genetic identity as "Hebrew DNA" especially when you are thinking about ancient Hebrews.

In general terms the DNA evidence lets us say two big things about Native American heritage with great certainty. First, in broad terms Native American DNA is most closely related to human populations that now reside in Siberia (not the Middle East). Second, the Native American population separated from the related Siberian population at least 10,000 years ago. Both of these things are consistent with the model that the most significant human migrations into this hemisphere happened around the end of the last ice age, as stone age people from Asia crossed into America on a land bridge, or possibly by following coastal routes. There has long been archaological and other evidence to support this idea, and DNA pretty solidly confirms it. It cannot exclude the possibility that less significant human migrations also occurred at different times and from different places. But these migrations would have to have been minor by comparison, since they have left no clear impact on the genetic signature of Native American from North, South, or Central America.

Or is it scientific flim-flam that can show whaever one wants to make of its testing results?


Recently there has been some new flim-flam from the LDS apologists. Rod Meldrum thinks DNA shows that the Book of Mormon took place around the Great Lakes. David Stewart thinks DNA evidence is consistent with Book of Mormon people serving as the foundation of ancient civilization throughout the hemisphere. Neither of them have genetics training and simply don't understand the literature, but they try to sound like experts. Keith Crandall, a professor at BYU, recently claimed in a FAIR video production that DNA found in Central America lends support to the idea that the Book of Mormon happened in the lands of the Maya, but he is simply cherry picking some convenient bits of DNA that are fully consistent with an ancient Asian migration, and I find this disingenuous and frankly disappointing coming from him. Yes, this stuff is all flim-flam.

Posted: Mon Aug 04, 2008 4:35 am
by _Danna
There are heaps of good sites with information. And much more reliable than asking people (like me) who have 'issues'. Here is a start:

http://www.dnaftb.org/dnaftb/1/concept/index.html

Speaking of South Seas people, a friend of mine was in a team working on Maori origins:

http://www.abc.net.au/catalyst/stories/s823810.htm

They had no religious agenda at all. Adele was somewhat amused when I told her what their work did to the theory of a Nephite origin for Maori! A south american origin has alway been up for discussion since the Kon Tiki and Heyerdahl's work - a non-religious theory.

Posted: Mon Aug 04, 2008 4:44 am
by _Hally McIlrath
DNA evidence seemed to work just fine in substantiating claims made by African Lemba tribes of their ancient (2,500 years ago, the exact time frame of the Book of Mormon) Jewish origins. The evidence was there, matching their oral history.

Image

http://en.wikipedia.org/wiki/Lemba

"A study from 1996 suggested that more that 50% of the Lemba Y chromosomes are Semitic in origin. The fact that the Cohen modal haplotype is found with low frequency in other Semitic groups supports the Lemba claims of a paternal Judaic ancestry."

One wonders why the same evidence is so difficult to find on this continent...

Posted: Mon Aug 04, 2008 2:41 pm
by _The Dude
Danna wrote:A south american origin has alway been up for discussion since the Kon Tiki and Heyerdahl's work - a non-religious theory.


Heh, those theories would also be non-scientific. DNA evidence shows polynesian origins to be south Asian, not south American.

Posted: Mon Aug 04, 2008 2:46 pm
by _The Dude
Hally McIlrath wrote:
"A study from 1996 suggested that more that 50% of the Lemba Y chromosomes are Semitic in origin. The fact that the Cohen modal haplotype is found with low frequency in other Semitic groups supports the Lemba claims of a paternal Judaic ancestry."

One wonders why the same evidence is so difficult to find on this continent...


This is not a fair request and the reason is right there in your quote (bold). Why should we think that Lehi and Ishmael had the Cohen haplotype?

Posted: Mon Aug 04, 2008 6:22 pm
by _silentkid
The Dude wrote:Keith Crandall, a professor at BYU, recently claimed in a FAIR video production that DNA found in Central America lends support to the idea that the Book of Mormon happened in the lands of the Maya, but he is simply cherry picking some convenient bits of DNA that are fully consistent with an ancient Asian migration, and I find this disingenuous and frankly disappointing coming from him.


Wow. I didn't realize this. I wonder what Dr. Whiting's position is on this? Crandall is well-respected in his field...I'm surprised to see him getting more involved in apologetics. I don't see this as a good thing for the Department of Integrative Biology at BYU.

Posted: Mon Aug 04, 2008 6:28 pm
by _Hally McIlrath
The Dude wrote:Why should we think that Lehi and Ishmael had the Cohen haplotype?



We shouldn't; but we should think that they would not have Mongolian DNA, if claims for their Jewish origins are correct.

Posted: Mon Aug 04, 2008 6:44 pm
by _The Dude
Silentkid

silentkid wrote:Wow. I didn't realize this. I wonder what Dr. Whiting's position is on this? Crandall is well-respected in his field...I'm surprised to see him getting more involved in apologetics. I don't see this as a good thing for the Department of Integrative Biology at BYU.


Since Crandall became a BYU professor he has recently joined the Church. I don't see this as a good thing for his credibility, especially when it leads him to say things like this:

"The most recent DNA evidence that I’ve seen, in terms of peopling of the Americas, shows this Middle Eastern haplotype at greatest frequencies in the Mayan people; so if that’s your perception of where Lehi and company set up shop then the DNA evidence would be consistent with that."


It's terribly misleading. Simon Southerton looks at Crandall's "recent DNA evidence" as well as a bunch of other flim flam from LDS apologists.

Hally: you have it right that the Mongolian DNA is the real problem. Bringing up Cohen haplotype is unnecessary, even greedy in my opinion, and apologists have a heyday with it. In my experience it's better to not distract from the problem of Mongolian DNA.