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Richard III's mtDNA and and Y chromosomes

I've been very intrigued by the story of the identification of Richard III's remains, published in Nature a couple of days ago. For an occasional genealogist like myself, the connection between the historical lines of descent and the genetic evidence was particularly intriguing. It is pretty amazing that two separate and verifiable mother-to-daughter lines, one of 17 generations and one of 19, were provably established from Richard's sister, Anne of York, to people alive in London today.

The first line of descent, to cabinet-maker Michael Ibsen, included a number of women whose husbands and fathers - or in one case, daughter/sister/aunt - were notable enough to have made it to Wikipedia. I edited the relevant articles to make reference to this (Sir Robert Constable, Henry Chomley, Thomas Belasyse, Sir Henry Slingsby, John Talbot, Sir Henry Gough, Barbara Spooner Wilberforce, and Edward Vansittart Neale). When the findings were first announced in February 2013, it was also stated that another line of descent had been identified, but that the living individual concerned did not wish to go public. I wondered whether this might be a descendant of the musician Margaret Harrison, referred to in an earlier Guardian piece (one-time fiancée of Percy Grainger, daughter of the painter Peter Harrison and the writer Alma Strettell); and if so whether this would really help much, given that such a person would have been not so many generations removed from Michael Ibsen; any failure of methodology with regard to his lineage would likely apply also to Margaret Harrison and her descendants.

But in fact it turned out to be much more robust. Wendy Duldig, a social policy researcher, is descended from a different daughter of Sir Robert Constable and his wife Catherine (née Manners), Richard III's great-niece, back in the early 16th century, with an extra two generations in her lineage compared to Michael Ibsen. Only two of the intervening links in Wendy Duldig's mother-daughter line had close family members who made it to Wikipedia (Sir George Wentworth and Sir Benjamin Truman), though one of them was painted by Gainsborough.(Truman's granddaughter Frances Read, see right). I found this in itself interesting - it shows that even without historical notoriety, the present-day researcher can pursue good genealogical links through the ranks of the upper middle classes.

It shouldn't be very surprising that such lineages rise and fall in income bracket and level of social prominence over the centuries. Taking it in the other direction, consider Mary Garritt, the wife of Thomas Webb, a surveyor in Stow-on-the-Wold in the mid-18th century. Her daughter Frances (1775-1862) married Thomas Salisbury, landlord of Marshfield House in Yorkshire. Their daughter Anne (1806-1881) married another gentry type, Edwyn Burnaby of Baggrave Hall in Leicestershire. Their daughter Caroline (1832-1918) married a widowed clergyman who was the grandson of a duke. Their daughter Nina (1862-1938) managed to bag an earl as her husband. Her daughter Elizabeth (1900-2002) did rather better than a mere earl. Her daughter, another Elizabeth, was born in 1926 and is still alive; those of you in the UK and Canada will find her depicted on certain useful everyday objects, ie money. But her direct female line ancestry can be traced back only six generations before it is lost in Gloucestershire.

These lineages are in fact very fragile. 17 generations on, Michael Ibsen is 57, and he and his siblings have no children, so the lineage from Sir Robert Constable's older daughter will die with them. 19 generations on, Wendy Duldig, in her fifties, is not reported to have siblings or children either. Had Richard III's remains been discovered forty years later, there might have been nobody around to compare his DNA with. There may be other undocumented maternal line descendants still around, daughters whose descendants were written out of the record for reasons easy enough to envisage; but the Leicester researchers seem to have done a pretty thorough job and it's difficult to imagine that much slipped past them. On the other hand, we know for certain that everyone alive today had at least one female-line ancestor who was alive in 1485. We must all be descended maternally from a fairly small number of women even going back only a few centuries. Mitochondrial Eve is reckoned to have lived 100,000-200,000 years ago, but for a lot of us, our most recent common maternal ancestor will have been much closer to the present day.

A couple of demographic notes. The average mother-daughter age difference in Michael Ibsen's lineage is 30.5 years, which is perhaps a little older than I had expected. The average mother-daughter age difference for Wendy Duldig's lineage is 27.5 years, which I find less surprising. The biggest generational jump is 42 years, between Michael Ibsen's grandmother and his mother. There are just four other births to mothers over 35 among the 33 births in the two lineages - Michael Ibsen's great-grandmother, her grandmother, Wendy Duldig's grandmother, and poor Anne of York who at 37 died giving birth to Anne St Leger in 1476, the link that kicks off the entire process. At the other end, there are no provable teenage mothers, though it's quite likely that at least one of the uncertain early 16th century 20-year-olds would have qualified.

Three women are known to have outlived their daughters (one seventeenth-century, two eighteenth-century). Two of these lived to over 90 (both born in the seventeenth century and living to the eighteenth century). The average lifespan of the women born in the fifteenth century was 43.5 years; of those born in the sixteenth century, 47.8; of those born in the seventeenth century, 62.4 (skewed by the nonagenarians, though the Duldig lineage is also pretty robust in general in that era); for both the eighteenth and nineteenth centuries, 70.6 years; and for the two born in the twentieth century, 79. (I have no data on the ages of the fathers.)

It's also interesting to note that Michael Ibsen's family emigrated to Canada, and Wendy Duldig's to New Zealand; but both Ibsen and Duldig have ended up in London.

Finally, the newspapers had great fun with the other side of the story, that the Y-chromosome analysis for male descent failed; comparison of Richard III's DNA with that of several known descendants of the fifth Duke of Beaufort showed that they did not have a common male ancestor in Edward III, as had been thought from historical records, so therefore at some stage the recorded father-son link did not reflect the biological facts. Does this mean that the entire British royal line is illegitimate? Well, probably not - or at least not for that reason!!! Four generations separate Richard III and Edward III, but the fifth Duke of Beaufort was 15 generations removed from his royal ancestor; on the face of it, it's therefore almost four times as likely that the bogus link is on the Beaufort side rather than the York side. On top of that, of the 15 Beaufort side links, only the first two are shared with Henry VII. So if for some peculiar reason you believe that Elizabeth II has a right to rule Britain and various other places due to Henry VII's descent from John of Gaunt, you can probably rest easy.

Comments

( 11 comments — Leave a comment )
ericadawn16
Dec. 6th, 2014 03:53 pm (UTC)

I want them to find out who is related to his father's side in modern times but none of the articles stated doing that.

redfiona99
Dec. 6th, 2014 06:36 pm (UTC)
I did get very confused about why they were repeating ancient gossipy slander about Phillipa of Hainault as though it were historical fact. And then I realised I was shouting at the computer screen and should probably go for a walk ;)
nwhyte
Dec. 6th, 2014 07:52 pm (UTC)
I think a more obvious option is the paternity of the 4th Duke of Beaufort, whose mother bore the 2nd Duke two sons, in contrast to his two other marriages which were childless...
parrot_knight
Dec. 6th, 2014 08:08 pm (UTC)
The first two marriages of the second duke of Beaufort ended when the duchesses died in childbirth, says The Complete Peerage, so the case isn't as cut and dried as it first might appear.

ETA: I see it's the second marriage which produced the third and fourth dukes, not the third marriage as I first supposed. The third wife was childless by both her husbands, her second husband being the fourth earl of Dundonald.

Edited at 2014-12-06 08:11 pm (UTC)
nwhyte
Dec. 7th, 2014 10:46 am (UTC)
Ah, well if the first wife died in childbirth (jeepers, married at 14 to the 18-year-old Duke, died at 17...) that probably knocks that theory on the head!
(Anonymous)
Dec. 7th, 2014 12:35 pm (UTC)
False paternity
was probably a bit more common among the aristocracy and gentry than in the population at large. You had more arranged / loveless marriages, several sorts of fertility-decreasing diseases and bad habits endemic to those classes, lots of opportunities for female infidelity (husbands away for long periods of time, lots of visiting back and forth, wives with relatively high levels of privacy and access to economic resources), and above all the relentless pressure to produce a male heir.

Note that there are several possible reasons for false paternity. The one we all immediately think of is a wife presenting her husband with a child actually fathered by another man. But there are a few others, including "'pregnant when married"', switched infants (yes, that could happen) and the warming-pan baby scenario.


Doug M.
parrot_knight
Dec. 8th, 2014 02:01 am (UTC)
Re: False paternity
Indeed. Francis Egerton, first earl of Ellesmere, was widely believed not to be the son of his official father the first duke of Sutherland; the sixth and seventh (present) dukes of Sutherland are his descendants. One duchess of Gordon assured an anxious nobleman courting one of her daughters that there was not a drop of Gordon blood in her daughter's veins and she would therefore not fall prey to the ducal Gordon family's supposedly hereditary insanity.
jeffreyab
Dec. 7th, 2014 03:32 pm (UTC)
I have always regarded Elizabeth II as being monarch by descent from Henry VII's wife Elizabeth of York. Henry VII was monarch by right of conquest like William the First and Oliver Cromwell.
alaimacerc
Dec. 15th, 2014 11:52 pm (UTC)
How large a number of extant matrilineages have you in mind when you say "fairly small"?

If every woman had exactly two children, the mt-lineage extinction rate would be 0.25, or something like 99.7% over 500 years (equating that to 20 generations). That'd be about 1.5m such ancestors. Women having different numbers of children will only lower it from there. (If population growth were factored in, we'd have a fairly secure upper bound, but that seems rather complex to do. Hence, I didn't try to do it!) Any more bids?

I now have a burning desire to round up the population and do complete mitochondrial sequencing on everyone. Would that be so very wrong?
nwhyte
Dec. 16th, 2014 11:37 am (UTC)
Very interesting thought. I reckon the average length of mother-child generations is nearer 28 than 25, which skews things a bit. You can very crudely approximate population growth from global 500 million in 1500 to global 7 billion in 2012 as an annual increase of 0.52%, 13.75% per 25 years, 15.53% per 28 years. (Of course this is unrealistic as the big surge is in the last 250 and especially the last 100 years.)

I'd be interested to see what you think, but my gut feeling is that an expanding population will keep some matrilineal descents in play longer than they might otherwise have been.

Hmmm, will look into this a bit more...
alaimacerc
Dec. 16th, 2014 09:02 pm (UTC)
I think you're right, population growth is too significant a factor to ignore, even in the context of the hilariously oversimplifying assumptions I was making elsewhere. If I'd extrapolated back further on the same basis, we'd have Mitochondrial Eve in around 250AD. Oops. Also the result of another basic flaw, relating to "robust" lineages with many survivors in a given generation, but I'm not quite so sure how to readily correct for that one.

If we assume each woman has exactly 2.3 children (yes, I know!) that's a matrilineage survival chance of more like 80% per generation, and gives about 9m ancestors for 18 generations. However, I don't think 28 is a realistic generation length as a global estimate for that time interval. I can imagine that there's the sort of difference in the post-med period by class as there presently is by country, tending to account for what you're seeing in your sample data. For comparison it's 5m for 20 generations, 3m for 22.

A slightly less crude model might approximate family size with a Poisson distro, and keep a count of the representatives for each lineage. That'd need actual code, though, not just futzing around in a calculator... Maybe if I get a bad dose of cabin fever around Boxing Day or so.
( 11 comments — Leave a comment )

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