anglo-saxon burials and genetics in england

here’s a map (on the left) of anglo-saxon burial sites of the 5th to 7th centuries from “Anglo-Saxon immigration and ethnogenesis” compared to the distribution of the eastern, central, and southern english genetic cluster (red squares on map to right) from leslie et al. who found between 10-40% of the ancestry of those english to be anglo-saxon:

harcke - anglo-saxon burial sites 5th to 7th-8th centuries

that is all! (^_^)

previously: free cornwall now!

(note: comments do not require an email. anglo-saxon burial: lady and her cow.)

traditional family systems in medieval britain and ireland

remember emmanuel todd’s traditional family systems, 1500-1900? here they are again:

i wanted to try to extend this map back to the medieval period. here’s what i’ve got for the british isles after the arrival of the anglos, saxons and jutes (and frisians?) and after they converted to christianity. so, ca. 800-900s to maybe the 1200s. something like that (see color key above – note that i haven’t updated areas outside the british isles to reflect what was going on in those places during the medieval period):

pretty much all of ireland remained having todd’s endogamous (patriarchal) community families throughout the middle ages. in fact, todd is somewhat misleading in including ireland as a stem-family country between 1500-1900 since apparently the stem family didn’t really appear in ireland until after the 1850s. hmmmm.

western regions of britain — western scotland, wales and cornwall — also stuck with the endogamous community family system throughout the middle ages. so did the peoples in the anglo-scottish border areas — the border reivers. in fact, they were clannish right up through the seventeenth and eighteenth centuries — at least! — when many of them emigrated to what would become the u.s.

east anglia and kent, as we recently saw, also had community families in the medieval period, but they (i think) married out more, so they would be classified as exogamous community families. joint families were common in medieval east anglia and kent, but not so much crazy, infighting clans. there was also little manorialism in east anglia and kent compared to central england, but more than in places like scotland or ireland. remember that the manor system relied on nuclear families and, coupled with the oubreeding demands of the christian church, manorialism broke down genetic relatedness and extended family systems in the population.

the heartland of manorialism in england was central englandmercia and wessex. this is where there was the greatest number of manor estates — the most tenant farmer peasants and others bound to the land in service to a manor — the hardest push for outbreeding and nuclear families. interestingly, this is where hackett fisher’s cavaliers and indentured servants came from, sorta maintaining in the new world the ages old tradition of masters and servants from this region of britain.

i may not be right in delineating central england as having “absolute nuclear families” during the medieval period. perhaps they had more stem families, i’m not sure. what they definitely didn’t have, though, were extended community families of any sort.

not sure what was going on in northeast scotland.

sometime between the middle ages and the modern period, the community family systems disappeared (for the most part) and nuclear and stem families became the norm throughout the british isles.

previously: todd’s family systems and the hajnal line and emmanuel todd’s absolute nuclear family and east anglia, kent and manorialism

(note: comments do not require an email. caerlaverock castle, scotland. cool.)

inclusive fitness stuff

i think inclusive fitness is one of the coolest concepts. ever. it doesn’t explain everything in Life, of course, but it explains a lot. it’s certainly helped me to make sense of why people (most organisms) behave in the ways that they do towards other individuals.

here are some neat examples of inclusive fitness affecting human behavior from robin (ian macdonald) dunbar [pgs. 137-39]:

[T]here is plenty of empirical evidence to suggest that, irrespective of the importance of social kinship, biological (i.e. genetic) kinship does play an important background role in the decisions that individuals make on how they should treat each other. In an analysis of Icelandic Viking sagas, for example, my colleagues and I showed that individuals were significantly less likely to murder close relatives (those related to ego as paternal cousins or better) than less closely related individuals (for a similar analysis of the English kings and queens, see Johnson and Johnson 1991). More importantly, their willingness to murder relatives was modified by the value of the action to the murderer: they were willing to murder distant relatives for trivial benefits (e.g. in a drunken brawl), but close relatives were only murdered if the gains were very high (e.g. by doing so, they inherited an earldom or land). Similarly, the Vikings were more willing to form alliances (or to make loans of ships, supplies, or men for expeditions) with close relatives than more distant ones, and when they did so were less likely either to demand explicit reciprocation or to renege on the agreement later.

“Note that it does not matter much how the Vikings themselves construed their patterns of kinship in these cases: these findings are based entirely on pedigrees constructed out of declared paternities. While the Vikings may have occasionally made mistakes about paternity, as we all do, paternity (and maternity) were important to them because they were associated with rights to land. These paternities are, of course, all taken from the Vikings’ written records, the sagas that were composed and/or written down mainly in the thirteenth century to provide records of individual family histories. As with all historical records, we might ask whether we can rely on them: after all, victors in history tend to colour the accounts they give with their particular view. There are, however, three relevant circumstances in this particular case. First, these accounts were written for public consumption by a very small community (medieval Iceland) where most people were intimately familiar with both the events and the characters described (in most cases, their own immediate ancestors): they would not have hesitated to say so if Snorri Sturlson (who was responsible for composing a great many of the Icelandic sagas in the 1220s and 1230s) had made too many egregious errors. Second, the Vikings themselves were very clear on real paternity (as best as they could define it biologically): despite the fact that fostering was a major feature of their world (as it continued to be into quite recent times throughout northern Europe), they made a clear distinction between foster-sons or foster-brothers and real sons or real brothers. Foster-sons could inherit land from a foster-parent if the parent so chose, but they did so by right of adoption and not by birth-right. Finally, even if the stories are complete fiction, we can still ask: did the Vikings compose their stories in such a way that they followed biological prescriptions…?

“Another example of the way biological kinship intrudes into everyday life is provided by Madsen et al. They asked individuals from two different cultures (the UK and South African Zulus) to undertake a painful isometric skiing exercise for the benefit of relatives (who received a monetary or food reward that was directly proportional to the length of time for which the exercise was maintained). In five replicates of the experiment, the duration (and hence reward value) declined with declining relatedness to the subject. In this study, considerable care was taken in drawing up lists of potential beneficiaries to ensure that they were biological relatives of the specified degree. While there was inevitably a great deal of variation across individuals, the bottom line is that, on average, closer relatives did better than more distant relatives (or even children’s charities) across four degrees of relatedness (self vs siblings/parents vs grandparents/uncles/aunts/nieces/nephews vs cousins). When real sacrifice is involved (the exercise becomes excruciatingly painful the longer one does it), altruism is titrated by genetic relatedness.”

what i find really interesting (obviously, if you’ve been reading this blog for any length of time!) is how inbreeding (and outbreeding) relates to inclusive fitness. sure, a brother might be really predisposed to help out his brother much more so than a distant cousin — but what if that brother is also a cousin? shouldn’t cousin-brothers, on average, be willing to help each other more than just regular brothers? the answer seems to be yes.

what should be kept in mind about inclusive fitness, though, is that there are other social behaviors that it probably affects in addition to altruistic ones. ever since bill hamilton published his ideas on inclusive fitness, most researchers have been focused on altruistic behaviors. but one of hamilton’s papers was entitled “The Innate Social Aptitudes of Man.” note, not the innate altruistic aptitudes of man — but the social aptitudes of man. hamilton obviously thought his idea applied to other behaviors as well in addition to altruism.

one of those other behaviors, i think, is a drive to exercise some control over who your relatives (i.e. other individuals who share YOUR genes) mate with. i haven’t seen much discussion of this amongst sociobiologists — i referred to one interesting study in my “nepotistic nosiness” post. there’s more of this going on, i’m sure — or i bet, anyway. people (and other organisms) want to control, to different extents, how their relatives pass on the genes which they share in common. and, like in the proven cases of altruistic behaviors, they probably want to exercise greater control over the reproductive practices over closer relatives. AND, where inbreeding occurs, there are probably even stronger drives to control the reproductive practices of relatives, e.g. all the reproductive controls in saudi arabia where the cousin marriage rates are currently 50%+.

just some thoughts.

(note: comments do not require an email. look! inclusive fitness.)