One of the more fertile grounds of modern genetics with all its various tools is that it makes for some interesting possibilities of inquiry in relation to the genealogy of aristocratic elites. The vast majority of us have very shallow roots in terms of genealogy. Some of this ignorance can be compensated if you have a clear and distinct group identity. If you are a Cohen or a Levite you have some notional conception of your line of ancestry. If you are a member of a Chinese patrilineage your genealogy likely can be traced at least hundreds of years, and possibly nearly one thousand years. Many European nations, in particular in the Nordic nations, have excellent church records which go back centuries.

High aristocratic elites are different in the scope of what we know. For most of history marriage for them was a matter of politics, not war, and the details of their lives were often recorded punctiliously. The births of royal children may have been attended by most of the court at some point to certify legitimacy. Some European lines have deep histories indeed. There are two direct male line descendants of Hugh Capet who reign today, Juan Carlos of Spain and Henri of Luxembourg. Hugh was a Robertian, a descendant of Robert of Hesbaye, who was a ruler of a region in modern Belgium. Robert of Hesbaye was derived from the Frankish elite, but the details seem to be unclear. But it seems then that Juan Carlos of Spain and Henri of Luxembourg should be of Robert of Hesbaye’s lineage, and so have a paternal line going back 1,200 years.

I began to think of this when a friend with a strong interest in genealogy pointed me to this short article, Genetic analysis of the presumptive blood from Louis XVI, king of France:

A text on a pyrographically decorated gourd dated to 1793 explains that it contains a handkerchief dipped with the blood of Louis XVI, king of France, after his execution. Biochemical analyses confirmed that the material contained within the gourd was blood. The mitochondrial DNA (mtDNA) hypervariable region 1 (HVR1) and 2 (HVR2), the Y-chromosome STR profile, some autosomal STR markers and a SNP in HERC2 gene associated to blue eyes, were retrieved, and some results independently replicated in two different laboratories. The uncommon mtDNA sequence retrieved can be attributed to a N1b haplotype, while the novel Y-chromosome haplotype belongs to haplogroup G2a. The HERC2 gene showed that the subject analyzed was a heterozygote, which is compatible with a blue-eyed person, as king Louis XVI was. To confirm the identity of the subject, an analysis of the dried heart of his son, Louis XVII, could be undertaken.

Let’s assume that the results are of Louis XVI. My friend was very interested in the fact that Louis XVI’s uniparental lineages were atypical; the direct male and female lines. I don’t know much about this area, but his maternal lineage was an undocumented branch of N1b. More common among Central Eurasian peoples than Western Europeans. His paternal lineage, of more interest because of our genealogical depth in the form of the remaining Bourbons, was a variant of G2a, again, of a branch or type which does not exist in current databases, though more common in the east of Europe than in the west. These data as to the distinctiveness of Louis XVI’s uniparental lineages need to be framed in light of the recent history of attempting to divide the French populace by class and ancestry; some theorists modeled the French elite as descendants of German Franks, while the commoners were Gallo-Romans. This narrative has long been out of fashion, but the cosmopolitan nature of the high nobility of Europe does mean that they will be distinctive and atypical (ergo, the tension between the nationalist and aristocratic ethos).

Of more interest for me is the discussion about the genetics of eye color and Louis XVI:

The amplification of the HERC2 gene provides controversial evidence on the physical appearance of the subject studied. Of course, lack of the rs12913832G allele would immediately imply that the subject is not Louis XVI because the presence of this variant is required for blue eyes. However, while most of the rs12913832 heterozygotes have hazel, brown or black eye colour, still about 15.8% of them (in a total sample of 388) have blue eyes The fact that both his parents, the Dauphin Louis-Ferdinand and Marie-Josephe of Saxony had brown eyes, as shown in their respective portraits available, makes slightly more probable that Louis XVI was heterozygous at rs12913832, despite having blue eyes….

They moot the real possibility that this isn’t Louis XVI’s sample. But what about issues of paternity? The probability is low for elite lineages, especially royal ones, but certainly not zero. More importantly, surveying the Y chromosomal lineages of aristocratic families would be very informative in getting a better grasp of the nature of human fidelity at the commanding heights. From what I have seen in the literature all things being equal culturally it is in low status lineages that paternity uncertainty looms largest in a concrete manner. This is balanced against the fact that the consequences of paternity uncertainty are graver in high status lineages, since paternity and property have a stronger relevance in kin-groups which have substantial levels of intergenerational wealth transfer.

Balanced against this is the dynamic of skew toward elites in demographics. In pre-modern times it seems likely that the top half, and especially top ten percent, of a society would contribute more to the next generation. Because of social (primogeniture) and economic (Malthusian era growth rates) pressures many of these offsprings of elites would descend down the ladder of status, presumably taking up the slots of commoners who did not reproduce above replacement. Oliver Cromwell is a classic case of a man born into the lower gentry whose ancestors were far wealthier and illustrious.

We don’t have the records of low status people for most of history. Additionally, we are unlikely to have marked graves from which DNA can extracted. But sometimes getting half the picture can allow you to construct the whole. A better map of the genes of the European nobility, their patterns of relationship, as well as extractions from tombs and mausoleums, would give us a very fine-grained understanding of the demographic parameters of this population. Though I’m not sure that some of the European nobility would be totally open to finding out the facts, as opposed to the myths.

October 14th, 2010 Tags: Genetic History, Genetics
by Razib Khan in Genetics | 5 comments | RSS feed | Trackback >