Friday 11 October 2019

No Neck

With a very expensive education, some surprising things clash up against each other in my head. So surprising indeed, that occasionally I cannot follow myself when I read some earlier pieces in The Blob's back-catalogue. Last month, I tasked my students in Yr1 Quantitative Methods for "Group Work and Presentation". This required them to pick a topic, do some collaborative research, summarise it on half a dozen powerpoint slides and present that in a 10 minute talk. One group from the Brewers, Distillers & Fermenters class had chosen to do chorizo but there was some discussion about the pronunciation. I explained <TMI TMI!> that they had a choice: choritho or choriso. The latter being easier for Irish eyes and ears, Andalusians and all their South American descendants.  The former being preferred in the rest of Spain because their king Carloth Thinco had a lithp. He had a lisp, possibly because of the peculiar and distinctive architecture of his Habsburg jaw. That recognisable face was cemented into the dynasty because they would marry each other. Vice is nice but incest is best - the game the whole family can play.</TMI TMI>  Our Brewers decided to follow Andalusia rather than Madrid.

Don't get away with the idea that inbreeding is only long ago and far away. A certain amount of endogamy is expected if you live in a village without cars or buses; or in a wider community [Hutterites, Ashkenazim] where conventions limit the available partners. My Pal Johnnie, who grew up a Protestant in Tuam Co Galway, was faced with a choice of three potential opposite sex partners from his church; none of whom was less than 40 years old. When I knew him 25 years ago, he had turned sufficiently that he was dating a very nice Catholicker girl from Sligo whom he's met in Dublin.

An extensive [exec summ] and exhaustive [full paper] study of the 456,414 genomes from the UK BioBank has been carried out by a group from U. Queensland, Brisbane, AU. They analysed the status of each of 300,000 genetic variants SNPs in both copies [maternal and paternal] of these these peoples DNA.  They found that the genomes of 125 of them or "1 in 3,652" people born in the United Kingdom between 1938 and 1967 show extreme inbreeding, indicating couplings between full siblings, a parent and a child, a grandparent and a grandchild, all of which are specifically forbidden by the Church of England's Table of Kindred and Affinity. Most SNP variants have two possibilities from the choice of four nucleotides A T C G. If a string of SNPs in a particular part of a maternally inherited chromosome 
A - G - G - G - C - T - T - A -T - C - C - T - C - A - T
is also found in the equivalent part of Dad's teaspoonful
A - G - G - G - C - T - T - A -T - C - C - T - C - A - T
it could have happened by chance (there are only 4 possibilities at each place after all to the odds are about 4^15 = 1bn-to-1) but, as the duplication extends, this explanation becomes increasingly unlikely.  They found that this ratio of 1/3500 is about the same rate of reports to the police of incest (11,200 cases in a population if 55 million). Acknowledging that reported cases of incest are likely only a fraction of actual cases of incest (everyone knows incest is frowned upon by polite society, so the perps aren't going to bruit it abroad?) it suggests to me that motherfuckers use condoms. I never thought I'd have occasion to utter that phrase! It turns out (I'm sure you knew this already, but I live a very sheltered life) there is a brand of condom called Motherfucker Rubbers.

In a sense this is like a genetic disease and its occurrence has about the same prevalence as Duchenne Muscular Dystrophy DMD (1:3500 live births); haemophilia (1:10,000); cystic fibrosis CF (1:2,000 in Ireland, less elsewhere). 

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