Understanding whether inbreeding accounts for early mortality is a long-standing concern in demographic research. Analyzing Bedouin villages in Bekaa, Lebanon, in which the marriage rate among first cousins is more than twice the national average, a new study appearing in the October issue of Current Anthropology finds that the greatest single determinant of infant mortality is not closely related parents – though this does present a significant risk – but short birth intervals.
The Bekka Bedouin are Sunni Muslims. Traditionally nomadic, migrating with herds of sheep and goats to pastures in the Syrian desert, they have recently become more sedentary, though a continuing preference for kin as marriage partners – particularly ibn ‘amm (father’s brother’s son) or bint ‘amm (father’s brother’s daughter) – remains “a salient feature of Bedouin matrimonial life,” writes Suzanne E. Joseph (University of Massachusetts, Dartmouth). About 47 percent of Bedouin marriages are between first cousins. Thirty-three percent are patrilateral, that is, between the children of brothers.Analyzing a sample of 1,399 Bedouin children, Joseph examined the mortality rate for infants (
As Joseph explains, the preference for choosing relatives as marriage partners may be a default marital strategy in situations where geographic isolation restricts the size of the mating pool, such as in nomadic societies. In sedentary societies, reproductive isolation may have an economic angle, preventing the fragmentation of property or facilitating unions among the poor by allowing them to circumvent dowry payments.
“While there is a heightened risk of infant mortality associated with consanguinity, even after controlling for socioeconomic and demographic factors, there are also substantial social, economic, and emotional benefits to marrying kin,” Joseph writes. “Women in particular are able to draw upon the support of their family members after marriage, which enhances their position in the domestic unit.”
Among populations with a high level of familial endogamy, there may also be a relatively high risk of recessive disorders which develop in childhood. However, the children of Bedouin first-cousin parents were not significantly more likely to die in childhood, Joseph found.
Indeed, the most statistically significant factor in a Bedouin child’s survival – whether the child of first cousins or not – is birth interval, Joseph reveals. For every additional month that passes before the birth of the next child, the odds of infant death decrease by 3.7 percent.
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The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
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Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...
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