Gene Expression

In my discussion with Eliezer I referred to “recreational genetics.” Basically, “for entertainment purposes only” genetics. For example, someone with blue eyes confirming that they have the alleles on OCA2 & HERC2 associated with blue eyes. Or a man with the surname O’Neill discovers that he has the Uí Néill Y chromosomal marker. Yes, people will pay money to find out these facts which are already highly probable.

I think the news that Charles Darwin was likely of the R1b Y chromosomal haplogroup falls into the recreational category, though due to Darwin’s fame the media has really been running with it. Let me point to the Telegraph, Charles Darwin’s genetic history unlocked by DNA project:

Published almost 200 years after the birth, the results reveal that the father of evolutionary theory, who struck upon the theory that all humans are descended from one common ancestor, comes from a long line of adventurers, his forbears being some of the first modern humans to leave Africa for the Middle East.

Tests on Mr Darwin’s DNA, collected from a swab of his saliva, showed that his ancestors, and those of Darwin himself, were among the first wave of modern humans to leave Africa for the Middle East about 45,000 years ago.

From there, they travelled into Europe, surviving the Ice Age by migrating south to Spain, before moving north to England about 12,000 years ago.

The tests revealed that Charles Darwin belonged to the Haplogroup R1b, direct descendants of the Cro-Magnon people who dominated the human expansion into Europe and heralded the demise of the Neanderthals.


On a specific note, this story about R1b might be wrong, pending the rehashing of the current scientific consensus in regards to the expansion of R1b. On a somewhat more general note, it is not necessarily true that Charles Darwin’s forebears were among the “first modern humans to leave Africa for the Middle East,” because the likely majority position that I can gather from evolutionary genetics is that there was one major Out of Africa push, not multiple ones (though the idea that there were multiple waves Out of Africa does exist as a minority position, and was championed by Richard Dawkins in The Ancestor’s Tale: A Pilgrimage to the Dawn of Evolution).

But finally, the biggest issue is that this is tracing Charles Darwin’s patrilineage only. That is, the Y chromosome passed from father to son to son to son to son to son and so forth. If you are a patriarch in the Old Testament obviously this particular lineage matters a great deal (recall that the sons of Jacob who are the ancestors of the twelve tribes of Israel do not necessarily share the same mother). But for most people this isn’t particularly privileged.* To really get a good sense of Charles Darwin’s genetic heritage they should extract some DNA from his remains and run it through a SNP chip do the appropriate analysis. I assume they’ll discover that Charles Darwin was northern European. They’ll also note that his ancestors were from Africa at some point in the past, and migrated to Europe via the Middle East.

* Y and mtDNA lineages, the paternal and maternal lines, have been well developed because the lack of recombination makes them optimal for coalescent based phylogenetic analyses. Also, in the pre-PCR age the large quantity of mtDNA made it an ideal target for extraction.

Comments

  1. #1 Carl Zimmer
    February 8, 2010

    I think it has value as a legitimate attention grabber–not as revelation.

  2. #2 DavidB
    February 8, 2010

    Not very relevant, but Darwin’s oldest surviving descendant, his great-granddaughter Ursula Mommens, has just died aged 101. There is an obituary in the (UK) Times.

    I was going to say that she must have been his last surviving great-grandchild, but now I realise that she wasn’t: there are still Richard Keynes, H. B. Barlow, and probably others. Ursula’s father, Bernard Darwin, was CD’s first grandchild, the only one born in his lifetime, and he started his own begetting relatively early.

  3. #3 pconroy
    February 8, 2010

    Of course uniparental markers do not reveal the whole story about someone’s heritage, take for instance Henry Louis “Skip” Gates Jr, he is allegedly R-M222 – so a putative descendant of the Uí Néill – on his father’s side, whereas his mtDNA H – can’t recall the exact sub-lineage – is of a type found mostly in Ireland. So without seeing an image of him, and just going by uniparental markers, you would expect him to be Irish looking, which he isn’t.

  4. #4 John Emerson
    February 8, 2010

    Genealogy is about the same. My did was into it, and I’ve done some, and it’s as much fun as any other hobby, stamp-collecting or anagrams or whatever, but at the genealogical depth of three generations your ancestors are utter strangers to you. Not only didn’t you ever know them, but if you met them in the afterlife you’d have nothing to say.

    All lines of my family came to Iowa from protestant Europe or New England ca. 1850-1870, so my ethnic category is clear, but I already pretty much knew that and since I’m not a nativist it doesn’t do me any good.

    I do have a nice dinner party anecdote, though. One of my 8x-great-aunts, Hannah Dustin, has a monument in New England somewhere because of the Indians she killed. Her unmarried sister Elizabeth Emerson was hanged for infanticide.

    Cotton Mather gave sermons on each sister. Mather described Elizabeth as someone who believed only in this world and didn’t think of the next, which would describe most of us.

  5. #5 Alan Kellogg
    February 8, 2010

    From Iberia eh? Does this mean Charles Darwin could Basque in his fame?