Category: Genetics
Long head, short legs
January 31st, 2008 , by adminA possible reason why the long headed GT5 Warriors are often taller than GT3 Teachers and GT4 Explorers:
In the article the development of skull measurements and head measurements (length and breadth) and of the cephalic index, calculated from these measurements, since the Neolithic period are presented. The results obtained from the historical material are compared with those of living persons. The measurements as well of the skull as of the head show secular changes. The following general trend was found: an increase of body height is connected with a debrachycephalisation* and a decrease of body height is connected with a brachycephalisation. It can be emphasized that brachycephalisation/debrachycephalisation are part of the secular trend. Therefore environmental factors are responsible for the described changes of measurements of the skull and the head in a broadest sense.
* Debrachycephalisation: the tendency for head shapes to become less 'square-like' and more elongated over succeeding generations. Brachycephalisation is the opposite.
Is head size modified by environmental factors? Z Morphol Anthropol. 1998;82(1):59-66.
A hypothesis is framed about which any influences of the nutrition may cause variations of the cranium, but concerning physiological data, kinds of nutrition and special victuals' ingredients cannot still be mentioned. If such connexions are proved, at last the well known brachycephalization among European populations since the Middle Ages and the beginning debrachycephalization in the present time could partially be interpreted.
The brachycephalisation problem, a nutrition constitutional problem? Gegenbaurs Morphol Jahrb. 1989;135(5):689-96.
Probably why GT4 Explorers usually are thicker boned than GT1 Hunters:
A growing body of archeological evidence suggests that the dramatic climatic events of the Last Glacial Maximum in Europe triggered important changes in foraging behavior, involving a significant decrease in mobility. In general, changes in mobility alter patterns of bending of the midshaft femur and tibia, resulting in changes in diaphyseal robusticity and shape. This relationship between levels of mobility and lower limb diaphyseal structure was used to test the hypothesized decrease in mobility. Cross-sectional geometric data were obtained for 81 Upper Paleolithic and Mesolithic European femora and tibiae. The sample was divided into three time periods: Early Upper Paleolithic (EUP), Late Upper Paleolithic (LUP), and Mesolithic (Meso). In addition, because decreased mobility often results in changes in sex roles, males and females were analyzed separately. All indicators of bending strength decrease steadily through time, although few of the changes reach statistical significance. There is, however, a highly significant change in midshaft femur shape, with LUP and Meso groups more circular in cross-section than the EUP sample, supporting archeologically based predictions of decreased mobility. Sexual dimorphism levels in diaphyseal strength remain low throughout the three time periods, suggesting a departure in Upper Paleolithic and Mesolithic foragers away from the pattern of division of labor by sex observed in modern hunter-gatherers. Results confirm that the onset of the Last Glacial Maximum represents a crucial stage in Late Pleistocene human evolution, and signals the appearance of some of the behavioral adaptations that are usually associated with the Neolithic, such as sedentism.
Mobility in Upper Paleolithic and Mesolithic Europe: evidence from the lower limb. Am J Phys Anthropol. 2003 Nov;122(3):200-15.
However marauding GT1 Hunters are on average, taller than glacial refugee GT4 Explorers:
Long bone lengths of all available European Upper Paleolithic (41 males, 25 females) and Mesolithic (171 males, 118 females) remains have been transformed into stature estimates by means of new regression equations derived from Early Holocene skeletal samples using "Fully's anatomical stature" and the major axis regression technique (Formicola & Franceschi, 1996). Statistical analysis of the data, with reference both to time and space parameters, indicates that: (1) Early Upper Paleolithic samples (pre-Glacial Maximum) are very tall; (2) Late Upper Paleolithic groups (post-Glacial Maximum) from Western Europe, compared to their ancestors, show a marked decrease in height; (3) a further, although not significant, reduction of stature affects Western Mesolithics. Evaluation of possible causes for the great stature of the Early Upper Paleolithic samples points to high nutritional standards as the most important factor. Results obtained on later groups clearly indicate that the Last Glacial Maximum, rather than the Mesolithic transition, is the critical phase in the negative trend affecting Western European populations. While changes in the quality of the diet, and in particular decreased protein intake, provide a likely explanation for that trend, variations in levels of gene flow probably also played a role. Reasons for the West-East Mesolithic dichotomy remain unclear and lack of information for the Late Upper Paleolithic of Eastern Europe prevents insight into the remote origins of this phenomenon. Analysis of regional differentiation of stature, particularly well supported by data from Mesolithic sites, points to the absence of today's latitudinal gradients and suggests a relative homogeneity in dietary, cultural and biodemographic patterns for the last hunter-gatherer populations of Western Europe.
Evolutionary trends of stature in upper Paleolithic and Mesolithic Europe. J Hum Evol. 1999 Mar;36(3):319-33.
Not because of shorter upper legs, but rather shorter lower ones..
Among recent humans brachial and crural indices* are positively correlated with mean annual temperature, such that high indices are found in tropical groups. However, despite inhabiting glacial Europe, the Upper Paleolithic Europeans possessed high indices, prompting Trinkaus (1981) to argue for gene flow from warmer regions associated with modern human emergence in Europe. In contrast, Frayer et al. (1993) point out that Late Upper Paleolithic and Mesolithic Europeans should not exhibit tropically-adapted limb proportions, since, even assuming replacement, their ancestors had experienced cold stress in glacial Europe for at least 12 millennia. This study investigates three questions tied to the brachial and crural indices among Late Pleistocene and recent humans. First, which limb segments (either proximal or distal) are primarily responsible for variation in brachial and crural indices? Second, are these indices reflective of overall limb elongation? And finally, do the Late Upper Paleolithic and Mesolithic Europeans retain relatively and/or absolutely long limbs? Results indicate that in the lower limb, the distal limb segment contributes most of the variability to intralimb proportions, while in the upper limb the proximal and distal limb segments appear to be equally variable. Additionally, brachial and crural indices do not appear to be a good measure of overall limb length, and thus, while the Late Upper Paleolithic and Mesolithic humans have significantly higher (i.e., tropically-adapted) brachial and crural indices than do recent Europeans, they also have shorter (i.e., cold-adapted) limbs. The somewhat paradoxical retention of "tropical" indices in the context of more "cold-adapted" limb length is best explained as evidence for Replacement in the European Late Pleistocene, followed by gradual cold adaptation in glacial Europe.
* Crural index is the result of multiplying the length of the lower leg (tibia) by 100 and dividing it by the length of the upper leg (femur).
Brachial and crural indices of European late Upper Paleolithic and Mesolithic humans. J Hum Evol. 1999 May;36(5):549-66.
12/01/2007 Vodcast :: The GenoType Diet (Taster Status)
December 1st, 2007 , by adminSmart People R Saying Dumb Things
October 26th, 2007 , by admin
So now the eminent James Watson has stuck his foot in his mouth, adding to the long list of accomplished geneticists and behaviorists who perish in the minefield of actually saying what you believe. We'll add him to the club, which includes the great William Shockley, inventor of the transistor and those guys that wrote the Bell Shaped Curve.
He has courted controversy in the past, reportedly saying that a woman should have the right to abort her unborn child if tests could determine that it would be homosexual. He has also suggested a link between skin colour and sex drive, proposing a theory that black people have higher libidos, and claimed that beauty could be genetically manufactured.
Watson, a co-discoverer of the structure of DNA (along with Francis Crick, although one could make a strong case for some skulduggery concerning their 'expropriating' much of the work of Rosalind Franklin) ignited an uproar last week with remarks about the intelligence of people of African descent.
The 79-year-old geneticist reopened the explosive debate about race and science in a newspaper interview in which he said Western policies towards African countries were wrongly based on an assumption that black people were as clever as their white counterparts when "testing" suggested the contrary. He claimed genes responsible for creating differences in human intelligence could be found within a decade.
Utter hogwash. "Intelligence" has long been shown to be undefinable, largely because it is heavily subject to cultural, environmental and financial filters. Even more significantly, it is more likely determined at the epigenetic level (postgenomically) than at the levels of the genes themselves, being influenced by the health habits of the immediately preceding generations, or even more likely, the prenatal environment of the child.
"Absolute power corrupts absolutely," so perhaps Watson's gaff is just the result of having too many people kissing his butt for too long a time.
Have started learning the R computer language. Perl's graphic and statistic packages are quite weak, and a quick look at R shows me that the graphing capabilities alone are awesome. A lot of the multivariate data that was used in the GenoType Diets may fit in very well with this language, since most people have a hard time visualizing data in more than 3 dimensions, though in mathematics this is not a big problem. Perl remains my preferred language (mainly for sure quick and dirtiness; it's amazing just how fast you can get something up and going in Perl) and for 'data mining' (or perhaps in my case, 'data dredging').
Well, gotta go. The car service is picking Martha and I up in an hour to take us to the airport. We're headed up to Toronto where I'll be giving one of the presentations to the Ontario Naturopathic Doctors Association. It's a homecoming of sorts, since we lived up there for a while about twenty years ago. It's definitely one of my favorite cities, and I like attitude of the people at lot.
Estupendo
March 23rd, 2007 , by adminHad a few obligations to tie up last week in the EU, which allowed for a few days rest and relaxation in the south of Spain. The area is one of my favorites, with good food, sunshine and great culture. Revisited the famous Mezquita (mosque) in Cordoba, one of the true architectural delights of the world. At one time the second largest mosque in the world, the mosque was turned into a cathedral with the Christian capture of the city in the 12th century. Although there are numerous naves to various saints, these are all relatively underwhelming when compared to the intoxicating forest of columns, spandrels and arches that immediately confronts the visitor.
Here are a few pictures that don't do it justice:
The wonder of having two teenage daughters is that at the end of the day I'd calculated that we'd spent more time (45 minutes) at the local department store (El Corte Ingles) then at what is widely considered one of the greatest buildings in the world (35 minutes). Oh well, I have my video tapes.
Also took the time to reread James Mitchener's wonderful book Iberia which should be mandatory for all who visit the country. Although written in the 1950's and '60s, it is still a fresh and relevant look at the Spanish psyche, written by a true student and devotee.
During our all too brief time we stayed at a few of the government run hotels, called paradors. They are often in castles, palaces, fortresses, convents, monasteries and other historic buildings. Surprisingly from my last visit, in addition to the often ponderous local fare, which can vary from great to abysmal, there are now special menus for vegetarians and celiac diners, which are what we often chose from.
Although I have family in the north of Spain (near Barcelona) we were not in country long enough to travel the distance necessary to visit them, however hopefully in the fall we'll get a chance to shoot up there.
Returning back to New York's JFK airport we were assaulted by the aftereffects of a rather large ice storm, which blanketed the area with almost a foot of snow, which then compacted down to a blue stone-like ice, so I spent my first day back chiseling out our cars from the snowy depths.
¡Que lastima!
IfHI 2007 has hit the magical 60 day mark, which traditionally ramps up my stress levels a bit. Personally, I feel more comfortable going into this conference that with either of the prior two, having perhaps a surplus of material for the first time.
Enjoying Rex Dwyer's wonderful book about programming bioinformatic computer code Genomic Perl. Not for the fainthearted, but gosh, what a treasure trove!
Internal Archeology
January 6th, 2007 , by adminI recently got the results of my Genographic Testing back. As a test it is simple enough; you swab the inside of your cheek with a comb like device and send it off to the Genographic services for analysis. You can check on the progress of the test by logging into their site and it does take a while to get it performed- in my case about 5 weeks from submission. If I remember correctly, it cost about USD $150.
Women always do the form of ancestry testing called mitochondrial DNA (mtDNA) analysis, since this is the DNA that is passed continuously through the maternal lineage. Guys can do either mitochondrial DNA or Y chromosome analysis, which gives information on the paternal lineage. Since I'm more attuned to my Spanish heritage, I opted to do mtDNA though I'm going to do the Y chromosome as well.
It turns out that I'm Haplogroup T. It's not uncommon in Europe, but not the most common gene marker either (that is Haplogroup H). It seems to have developed in the Middle East (Anatolia) and moved into Europe with the spread of Neolithic agriculture, which jives with my ABO blood group, A.
Time to visit my friend Yaman and once again tour the old haunts!
Haplogroup T has a few subsets (T2, T3, T4 and T5) but I have only four SNPs (single nucleotide polymorphisms) in the so-called Hyper Variable Region (HVR-1) called 16126C, 16294T, 16296T and 16519C and these plant me in the rather unsatisfying T* subgroup made up of all T's who are not in any other subgroup.

Well, at least I'm not directly related to Jesse James although I am related to a lot of European royalty.
Take that Isa!
I always did feel a bit of connection to tragic-comic Czar Nicky and it's nice to think I can hit up a few royals for bus fare if needed.
Haplogroup T is closely related (derived, rather) from Haplogroup J, another Middle Eastern haplogroup, a fact which I find especially interesting in light of another recent discovery.
My mother's maiden name was Subira-Vidal, the Vidal from her mother (my grandmother's) side of the family. It turns out that Vidal in that part of Spain (Catalonia) was a name commonly adopted by Sephardic Jews who were forcibly converted to Catholicism during the Inquisition, the name "Vidal" being used as a substitute for "Chaim" both signifying "life." Not all Spaniard with the surname Vidal are of Sephardic origins, but many in Catalonia are.
My mother was born in a very small town near the Aragon-Catalonia border called "Masalcoreig" which the locals say is derived from a phrase meaning "The Moor's Rock.� In those halcyon days before the occupations and intifadas and especially in Spain, wherever you found Moors you usually also found Jews; often as doctors, scribes and tutors.
So I'm a quarter Middle-Eastern and Sephardic. Now I can't wait to see some of my old-timer Hassidic patients at the clinic so I can pull rank on them.
"Hah! Newcomers!"
Well, gotta go brush up on my Ladino...
Kol Tuv!



