Finnish Genealogy and Evolution

 

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There’s a great recent article in Scientific American entitled “What Finnish Grandmothers Reveal about Human Evolution” highlighting the research of biologist Virpi Lummaa.I’ve mentioned before that while genetics is a useful tool for genealogical research, genealogy can also be a useful tool for genetic research!Dr. Lummaa’s research does exactly that.

Dr. Lummaa used 200 years of genealogical records to study the influence of evolution on reproduction”

“The 33-year-old Finnish biologist, aided by genealogists, has pored through centuries-old tomes (and microfiche) for birth, marriage and death records, which ended up providing glimpses of evolution at work in humanity’s recent ancestors.”

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Esther Dyson and the “First 10”

Esther Dyson is a prominent force in the digital world, and is considered to be a member of the ‘digerati’ (a term for people who are the movers and shakers of everything technological).She is the daughter of the famous physicist Freeman Dyson and the mathematician Verana Huber-Dyson.

According to Wikipedia, the company that Ms. Dyson founded, EDventure Holdings, analyzes the impact of emerging technologies and markets on economies and societies.In addition, Ms. Dyson is on the board of the genetics company 23andme.Her interest in genetics and emerging technology is undoubtedly one of the main reasons she has decided to become one of the “First 10.”

The “First 10”

The “First 10” (or “First Ten”) references ten volunteers who are part of the Personal Genome Project, or the PGP.The PGP, headed by Dr. George M. Church of Harvard, aims to develop affordable personal genome sequences as well as user-friendly data applications.Initially, the project will start by releasing the sequencing and complete medical records of 10 individuals.Because of issues of risk versus benefit and informed consent, the first set of ten volunteers will be people who have a “master’s level or equivalent training in genetics or equivalent understanding of genetics research.”According to the PGP website, “[p]roduction costs per subject range from $8K for a limited subset of the genome to over $200K per subject to cover a significant fraction of their DNA.”According to a recent New York Times article, the “project’s volunteers will receive the one percent of their genome currently deemed most useful at a cost of $1,000.”This conflicts with the PGP’s description of the cost, and I’m not sure what the discrepancy is about.

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DYS464 and Male Infertility

Dr. Mark A. Jobling at the University of Leicester published a study in 2005 that examined DYS464, a Y-DNA marker commonly sequenced for genetic genealogical purposes. As it turns out, sequencing DYS464 can inadvertently detect an AZFc deletion. Deletion of AZFc (azoospermia factor c) causes spermatogenic failure and subsequently, male infertility. This marker is tested by at least 6 firms.

Dr. Jobling pointed out that a previous study had concluded that an AZFc deletion could be found in 1 in every 4000 males. In Dr. Jobling’s study there were 3 cases in 3255 males tested, which he states is “not significantly different from 1 in 4000.” A story in the New Scientist stated that “a study by Jobling’s team suggests that 1 in 1000 men has the deletion,” but I think that is an overstatement by the media. I haven’t seen anywhere that Dr. Jobling made such a statement – he was merely listing some of his data. Elsewhere, Ann Turner has suggested that at FTDNA, the number is around 1 in 8,000. Although the exact frequency has not yet been determined, it appears that it is rather low.

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The Measure of a Woman (or a Man)

My great-grandmother belongs to Haplogroup H, and I always feel a little bad for her.Not that I have anything against Haplgroup H’ers, but they got the short end of the stick.You see, currently all mtDNA sequences are compared to the Revised Cambridge Reference Sequence (rCRS), an mtDNA sequenced derived in the early 1980’s and recently updated.Since the source of most of the mtDNA for that sequence belonged to Haplogroup H, people who belong to Haplogroup H often have no deviations at all and their sequencing results tend to be a little boring.Imagine if your mtDNA testing company sends your results and they say: “You belong to Haplogroup H, and your deviations from the rCRS are as follows: 0.”You see, a little dull.

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The Qilakitsoq Mummies

A recent paper in the American Journal of Physical Anthropology examined mtDNA extracted from the hair and nails of eight Inuit mummies. These essentially freeze-dried mummies were discovered in 1972 in a natural tomb at Qilakitsoq in the Uummannaq Municipality of Greenland. Using C14 analysis, the mummies have been dated to approximately 1460.

The bodies were found in two separate positions about 1 meter apart. In Grave I, there were five bodies:

  1. I/1 = Male Infant #1 – about 6 months of age
  2. I/2 = Male Infant #2 – about 4 to 4.5 years of age
  3. I/3 = Female #1 – about 20-25 years of age
  4. I/4 = Female #2 – about 25-30 years of age
  5. I/5 = Female #3 – about 40-50 years of age

In Grave II, there were 3 bodies:

  1. I/6 = Female #4 – about 50 years of age
  2. I/7 = Female #5 – about 18-21 years of age
  3. I/8 = Female #6 – about 50 years of age

The researcher’s primary goals were to sequence the HVR1 region of each individual’s mtDNA, and then to compare the results to determine possible relatedness of the remains. All 8 individuals fell into Haplogroup A2, but belonged to three different maternal lineages which were mixed between the two grave sites:

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The Copernican Principle

I saw a recent article in the New York Times, “A Survival Imperative for Space Colonization” that grabbed my attention.I know it isn’t necessarily related to DNA, but I loved the article and the essence behind it, The Copernican Principle.

The Copernican Principle, is named after Nicolaus Copernicus, who stated that the Earth is not in a central, specially favored position.Although it might look like our galaxy is the center of the Universe, observers in all other galaxies would observe the same thing.This idea has been applied to the field of statistics.For example, if you are observing something and your location is not special, then you are observing the thing at a random point during its existence.That is, there is a 95% chance that you are seeing it in the middle 95% of its existence, and not during the beginning 2.5%, or the last 2.5%.That idea can be expressed using the following formula:

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Mitochondrial Eve and Y-chromosomal Adam

In the past decade, scientists have repeatedly referred to ‘Mitochondrial Eve‘, the (hypothesized) source of mtDNA for all humans alive today.  She is believed to have lived approximately 140,000 years ago in Africa.  There is also ‘Y-chromosomal Adam‘, the (hypothesized) source of every living man’s Y-DNA.  He is also believed to have lived in Africa, but more recently, between 60,000 and 90,000 years ago.  Thus, Mitochondrial Eve and Y-chromsomal Adam were not a couple – they were not the source of all human genetic material on the planet today.  Instead, the terms refer to the founders of all the mtDNA and Y-DNA respectively.

For a wonderful description of some of the genetic behind Mitochondrial Eve and Y-chromsomal Adam, go to “The Questionable Authority“, a blog which is part of Scienceblogs.  While you’re there, be sure to read the comments, where the discussion addresses the time disparity between the two DNA sources (140,000 years ago versus 60-90,000 years ago).

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