fyi – i occasionally make updates to some posts (you’ll find them @the bottom of posts — with a date if the update happened on a day subsequent to the post). if a post has fallen off the front page, then i post a little notice down below in the left-hand column under (cleverly named) “Updates” — just under “Recent Posts.” just left one there now, for example.

father’s brother’s daughter marriage

or fbd marriage (or patrilateral parallel cousin marriage). i mentioned this before (and i’m sure i’ll mention it again).

cousin marriage is pretty common in the world. but most peoples prefer to marry their cross cousins, i.e. (from the point-of-view of a son) father’s sister’s daughter or mother’s brother’s daughter.

however, a few groups of peoples preferentially follow the fbd system. korotayev (2000) convincingly showed that those peoples are mostly to be found in those areas of the world that were a part of the eighth century islamic caliphate. or, here:

he said (in that same article):

“Islamic law does not prohibit FBD marriage, nor does it impose (or even recommend) it (Schacht 1964; al-Jazi:ri: 1990:60-61). But most traditional cultures have a clear perception that marriage between a man and his FBD is incestuous. This is evident in the fact that in most languages a kinship term for FBD (or MSD) would be identical with a kinship term for one’s sister. This normally implies that marriage with a FBD (or MSD) would be perceived as equivalent to marriage with a sister (Korotayev 1999). There appears to be something here that Kronenfeld (pers. comm.) called a ‘cognitive problem’….”

i think fbd marriage is considered incestuous by most peoples because it creates strongly endogamous lineages. look here — here’s fbd marriage versus fzd (father’s sister’s daughter) marriage. look what happens: in fbd marriage, the men and the women all stay within the same clan. that’s hyper-endogamy if you ask me. in fzd marriage, in contrast, the women move between clans. (the straight lines are men, the dotted lines are women, and the big dots are, well, the union of a man and woman.)

continuing with korotayev, where on earth did fbd marriage come from?:

“At the time of its origin, FBD marriage had nothing to do with Islam. The cognitive problem solution seems to have occurred somewhere in the Syro-Palestine region well before the birth of Christ. Rodionov (1999) has recently drawn attention to the fact that this marriage pattern is widespread in the non-Islamic cultures of this area (e.g., Maronites or Druze) and that it has considerable functional value in this non-Islamic context in facilitating the division of property among brothers after their father’s death (Rodionov 1999). Like Rodionov (1999), I believe that this marriage pattern could hardly be attributed to Islamic or Arab influence here. It seems, rather, that this marriage pattern in the Islamic world and the non-Islamic Syro-Palestinian cultures stems from the same source.

“But prior to the time of Islam, the diffusion of the FBD marriage pattern was rather limited. The only adjacent area where it diffused widely was the Arabian Peninsula (Negrja 1981; Kudelin 1994), where its diffusion can be linked with a considerable Jewish influence in the area well before Islam (Crone 1987; Korotayev 1996; Korotayev, Klimenko, and Proussakov 1999). In any case, by the seventh century, preferential parallel-cousin marriage became quite common among several important Arab tribes (Negrja 1981; Kudelin 1994). In the seventh and eighth centuries, an explosive diffusion of this pattern took place when Arab tribes, backed by Islam, spread throughout the whole of the Omayyid Khalifate. Although preferential parallel-cousin marriage diffused (together with Islam and Arabs) later beyond the borders of the Omayyid Khalifate, the extent of this diffusion was very limited. Hence, the present distribution of FBD marriage was essentially created by the Muslim Arab conquests of the seventh and eighth centuries….”

interesting, huh?

i mentioned over here that i thought the practice should really be called father’s brother’s son marriage — not ’cause i’m a raving feminst who wants everything to be considered from the point-of-view of women (you should know me better than that by now!) — but, rather, because it seems to me to be the father-of-the-bride [“C” in chart below] who really wins out here genetically speaking (which is all that matters, right?). the father-of-the-bride gets to “reunite” his y-chromosome (that he shares with his nephew, his brother’s son) with a quarter of his autosomal dna (his daughter carries half of his autosomal dna) in any male grandkids that he has. what other grandfather gets to do that?:

so what?, you say. here’s what, says i (i.e. relatedness matters).

i also think it’s not a coincidence that, in these societies where fbd marriage exists, you also get these extremely paternalistic societies where women are shrouded in burkas or aren’t allowed to drive or whatever. also, the whole honor killing thing. like rs said here, the males in such societies become “super homies” with each other. exactly! why? ’cause they are really closely related genetically.

i suspect that both the degree and type of genetic relatedness in a society affect all sorts of behaviors of its members (especially those related to reproduction) as well as societal norms and even ideologies (again, especially those related to reproduction).

emmanuel todd seems to have gotten close to this idea as well, although i don’t think he got the genetic side of it (i haven’t actually gotten my hands on a copy of this book yet — gosh-d*rnit!). here’s a blurb about his book, “The Explanation of Ideology: Family Structure and Social Systems (Family, Sexuality and Social Relations in Past Times)”:

“Some parts of the world are dominated by communism, others by Catholicism or by Islam and yet others by liberal doctrines. Why should this be? And why has communism triumphed in Russia, China and Cuba, yet failed in Poland, Cambodia and Indonesia? No one knows. Certainly no clear answer lies in variation of climate, environment, race or, even, economic development. The argument of this book is that world variations in social ideology and belief are conditioned by family structure. The author analyzes the distribution of family forms throughout the world, and examines the relations between particular structures, and (for example) communism, totalitarianism and individualism, as well as the links between these forms and a variety of social phenomena – illegitimacy, suicide, infanticide, marital stability and inheritance laws. He offers evidence to support the belief that family structures and kinship patterns lie behind the ideologies that have shaped the history of the 20th century.”

yes, kinship patterns. and what do kinship patterns reflect? mating patterns.

here’s a little hint at what todd had to say about kinship patterns in the once-part-of-the-caliphate muslim world from a helpful reviewer:

“Endogamous Community Family:
a. Spouse selection: Custom, frequent marriage between the children of brothers.
b. Inheritance: Egalitarian – equality between brothers.
c. Family Home: cohabitation of married sons with their parents.
d. Representative Nations, Peoples, Regions: Arab world, Turkey, Iran, Afghanistan, Pakistan, Azerbaijan, Turkmenistan, Uzbekistan, Tadzhikistan.
e. Representative Ideology: Islam.”

it’s not the family structure that matters, it’s the mating patterns i say.

relatedness matters. a LOT, i think.

previously: cousin marriage conundrum addendum and all cousins are not created equal

edit – a nifty diagram of father’s sister’s daughter (fzd) marriage:

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detecting kin

Human ability to detect kinship in strangers’ faces: effects of the degree of relatedness

“The resemblance between human faces has been shown to be a possible cue in recognizing the relatedness between parents and children, and more recently, between siblings. However, the general inclusive fitness theory proposes that kin-selective behaviours are also relevant to more distant relatives, which requires the detection of larger kinship bonds. We conducted an experiment to explore the use of facial clues by ‘strangers’, i.e. evaluators from a different family, to associate humans of varying degrees of relatedness. We hypothesized that the visual capacity to detect relatedness should be weaker with lower degrees of relatedness. We showed that human adults are capable of (although not very efficient at) assessing the relatedness of unrelated individuals from photographs and that visible facial cues vary according to the degree of relatedness. This sensitivity exists even for kin pair members that are more than a generation apart and have never lived together. Collectively, our findings are in agreement with emerging knowledge on the role played by facial resemblance as a kinship cue. But we have progressed further to show how the capacity to distinguish between related and non-related pairs applies to situations relevant to indirect fitness.

the money quote graph:

related? if so, relatedness?:

how about these two?:

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where does language come from?

via dienekes (go there for all the juicy bits!):

Parallel Evolution of Genes and Languages in the Caucasus Region

“We analyzed 40 SNP and 19 STR Y-chromosomal markers in a large sample of 1,525 indigenous individuals from 14 populations in the Caucasus and 254 additional individuals representing potential source populations. We also employed a lexicostatistical approach to reconstruct the history of the languages of the North Caucasian family spoken by the Caucasus populations. We found a different major haplogroup to be prevalent in each of four sets of populations that occupy distinct geographic regions and belong to different linguistic branches. The haplogroup frequencies correlated with geography and, even more strongly, with language. Within haplogroups, a number of haplotype clusters were shown to be specific to individual populations and languages. The data suggested a direct origin of Caucasus male lineages from the Near East, followed by high levels of isolation, differentiation and genetic drift in situ. Comparison of genetic and linguistic reconstructions covering the last few millennia showed striking correspondences between the topology and dates of the respective gene and language trees, and with documented historical events. Overall, in the Caucasus region, unmatched levels of gene-language co-evolution occurred within geographically isolated populations, probably due to its mountainous terrain.”

i still can’t help thinking that different languages arise (arose) because different peoples think kinda differently. clearly speaking different languages can keep populations separated from one another (it’s easier to mate with someone with whom you can communicate) … but which came first? how we think or how we speak?

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number of libyan tribes…

…is rising exponentially, apparently.

last time i heard, there were around “140 different tribes and clans in Libya.” now i read that the tribal leaders from 851 tribes and tribal factions just got together for a little pep-rally! and these are just the ones (supposedly) supporting gaddafi:

Libyan Tribes Call for End to Armed Uprising

“Journalists were told that about 2,000 chiefs representing 851 tribes and tribal factions were in attendance, at the convention that was organised by the tribes, not the regime. However it seems that the convention drew only limited participation, with only tribal chiefs from three regions of western and central Libya were present….”

number of tribes in libya? a LOT. (guess it depends on how you slice it.)

previously: libya – land o’ tribes

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there was some discussion in another comment thread (starting here) about genocide and what, exactly, it is (i.e. how to define it).

bill hamilton thought that genocide (and some wars, in fact) is a reponse to differential birth rates between two (or more, i guess) populations sharing the same environment. from “Narrow Roads of Gene Land, Volume 2“, p. 280 (via race/hist/evolution notes, a treasure trove of interesting info, btw!):

“Increase of Ashkenazi Jews in eastern Europe in the span of the nineteenth century is said to have been almost fourfold (S. Jones, In the Blood: God, Genes and Destiny (HarperCollins, London, 1996)). This implies a doubling about every generation. Very surprisingly this fact seems almost never to be discussed as part causative background to the holocaust, an omission that continues even when claims of group competition are the focus.”

and more (from the introduction)…

“I suggested [during some speech] it might be useful for us to discuss the psychology of population situations and to give special attention to those where closely placed or intermixed distinct groups had strikingly different rates of increase. In particular, it might be useful to consider what this might do to competitive birth rates and aggressive instincts connected with population perceptions — in fact, also with the inception of wars. There was silence as I stopped. I’d wanted to explain my thought as far as I could in words that didn’t bring in my pet and as yet little accepted views about the importance of genetical kinship for human altruism and aggression. It had seemed to me that my case for the interest of this topic could be made for present purposes without that and based on known historical instances by themselves.

“The silence that came surprised and unsettled me, so I added something about every one having pride in his or her family and, perhaps not wanting to see descendants lost in a sea of strangers; while, in anything like a democracy, people would be not liking to imagine their own preferences and way of life being over-ridden by decisions deriving from ways of life either — for example, not caring about the countryside, urbanizing as far as possible, and so on [. . .]

“In an effort to be more explicit and to be taken more seriously, I then exposed some corner of my actual work, saying something about how we were all expected, as a result of population genetical processes — natural selection in fact — to have psychological biases that wouldn’t necessarily be easily visible on the surface but whose reality would come to the fore in situations where these rapid changes in a population’s composition were imminent. There was a matter of within- and between-group variances involved here, this applying to the very genes that made us. It wasn’t necessary to such ideas, I added, that shortages of land or whatever would be apparent right when divisive psychology took effect; it would be in this nature of the group psychology to anticipate what might be about to happen. [. . .] If we really wanted to understand why population is a difficult issue to discuss and to do anything about it in the world, I continued [. . .], it is very essential that we understand the evolutionary forces that have moulded reproductive and territorial psychology in humans — the features must be old, of course, started doubtless mainly in our Old Stone Age past. If we wanted to recommend policies to affect population trends in any direction today, we perhaps needed to discuss first the underlying motivations that all people had to possess — that must be there from the very fact that they themselves came form successful parentage and successful families of the past….”

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more plants playing favorites

artemisia tridentata — the common sagebrush. looks like a decent sort of plant. you know, the kind that would give any other plant a fair shake:


a. tridentata actually plays favorites! specifically, it favors clones of itself and other sagebrush plants that are closely related to it genetically:

Effect of genetic relatedness on volatile communication of sagebrush (Artemisia tridentata)

“Sagebrush (Artemisia tridentata) uses volatile cues to induce systemic resistance to herbivory within and between plants (so-called volatile communication). Previous study revealed that the volatile components varied among individuals and that sagebrush suffered less damage when it received volatiles from clonally potted genetically identical branches than when it received volatiles from genetically different potted branches. In this study, we investigated whether there are genetic relationships among individuals growing within 60 cm where volatile communication occurs under natural condition, and whether volatile components are influenced by genetic relationships. By using genetic analysis involving microsatellite markers, we found that genetically identical ramets which were thought to be clonally propagated and genetically closely related ramets were growing near to each other. In addition, volatile components were similar among genetically identical or closely related ramets. Our results imply that genetic relatedness and volatile similarities may influence the strength of induced resistance of ramets that received volatiles.

here’s what the whole volatile doohickey business is all about:

“The sagebrush communicated and cooperated with other branches of themselves to avoid being eaten by grasshoppers, Karban said. Although the research is in its early stages, the scientists suspect that the plants warn their own kind of impending danger by emitting volatile cues. This may involve secreting chemicals that deter herbivores or make the plant less profitable for herbivores to eat, he said.”

first sea rockets and now sagebrush? who knew that the plant world was so full of darwinian drama?!

previously: even plants do it

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reductionism works (pretty good) — again

some biogeographers came awful close (278 miles close, to be precise) to pinpointing osama bin laden’s location a couple of years ago by using biogeographical theories:

“They fingered the spots based on two theories on the distribution of biological species. One of them, the so-called distance-decay theory, states that the similarity and correlation between species at two locations decreases as the distance between them increases. As such, the geographers figure bin Laden can’t have gone far—he is believed to have fled Afghanistan’s Tora Bora region at the end of 2001—if he wished to remain on similar terrain in a familiar cultural environment.

Island biogeography, the other tool in the team’s theoretical analysis, posits that large, closely spaced pockets of life (islands) support more species and are less ravaged by extinction than small, isolated islands. With cities standing in for islands, the researchers speculate that bin Laden would most likely hide out in a large town with minimal isolation, because even though there’s more risk of being spotted he would also have access to resources needed to stay alive as well as under cover.

“These theories, they say, point to Parachinar in Pakistan’s Federally Administered Tribal Areas.”

“a” for abbottabad, “b” for parachinar:

reductionism works (on a certain level) ’cause we are just busy little biological creatures running around like all the other busy little biological creatures.

previously: reductionism works and more reductionism working

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