MOESAN
Elite member
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- Brittany
- Ethnic group
- more celtic
- Y-DNA haplogroup
- R1b - L21/S145*
- mtDNA haplogroup
- H3c
reliability of metric studies comparing "same" populations of different times
I found 2 digests of a survey made in the USA (maybe one of them in DIENEKE°:
yet, one of them reported erroneous facts (enthiusasm? scoop spirit?)
here under, a abstract:
my observations
1- how was selected the different samples of different times ? Same ethnic origin, precisely ?
White American is a very unprecise concept evolving with time : Irish Catholics ? German Protestants ? British ? Same mixture in same %s ober the centuries ??? Today the phenotypical aspect of white Americans is different enough compared to the 1960's ones : less irish, british or north-Europe origins, more South-Europe and slavic...a local genuine internal evolution is not alone at work there, rather an external one : other ligneages...
2- the social origin can play here too (selection) ...
3- the skulls linear mensurations described in the abstract are limited to the head height ; it is not the all mensurations... the volume ones could be linked only to the height ones, or not ? I noticed when I was young (1966-70), yet, that Americans presented seamingly (no mean for me to check it) higher skulls as a whole than the Europeans, even the northern ones, their forehead retreating slowly and the near horizontal summit of the head being shorter : in short, less « bombing » but higher forehead as a whole, more conic form of skull (they seamed to me too having bigger teeth as a whole : true teeths or prothesis?)- in Europe I rather notice what seams a diminution of head mensurations, at least when compared to body ones (particuliarly the height body ones and the feet ones)...Maybe the evolution in Europe and in the States are not the same ?
5-the difference between complete stature and femur growths strike me too: a very big difference : an internal evolution can explain a small margin but there !...
6- quality of sampling left on side, the quantity seams to me a bit scarce (1500 for all this period of 180 years is few for a so vaste land)
nevertheless, it remains a kind of truth behind these statistics - the changes in the way of living can surely modify some body internal proportions, but do'nt forget that new ethnic groups can send new proportions too! (here we state a global diminishing of legs compared to back lenght and head height -? maybe a link between back height and head height ? - all the way, concluding about time linked evolution is to be made very carefully
I found 2 digests of a survey made in the USA (maybe one of them in DIENEKE°:
yet, one of them reported erroneous facts (enthiusasm? scoop spirit?)
here under, a abstract:
»On the coat tails of Matt Ridley’s statement that humans are no longer evolving, comes news presented at last month’s annual meeting of the American Association of Physical Anthropologists that the heads of white Americans are getting bigger. Lee Jantz, Richard Jantz and Joanne Devlin, took about 1,500 skulls dating all the way back to the mid-1800s through the mid-1980s.
What they observed is year-by year the heads of this sample are growing in volume. The skull of the average male human has grown in height by 8 millimeters and in volume 200 cubic centimeters*. In women, the corresponding increases are seven millimeters and 180 cubic centimeters. This increase in volume is about the size of a tennis ball!**
An even more unique result is the disproportionate growth of the skull compared to the rest of the body. Since the late 1800′s, skull height has increased 6.8%. But body height has increased 5.6% and femur length has only increased about 2%. Where skull height has continued to change whereas the overall heightening has recently slowed or stopped.
my observations
*: false : millimeters !!!
** : a space equivalent to a couple of small peas
Yet a story that recall me some others in modern surveys:1- how was selected the different samples of different times ? Same ethnic origin, precisely ?
White American is a very unprecise concept evolving with time : Irish Catholics ? German Protestants ? British ? Same mixture in same %s ober the centuries ??? Today the phenotypical aspect of white Americans is different enough compared to the 1960's ones : less irish, british or north-Europe origins, more South-Europe and slavic...a local genuine internal evolution is not alone at work there, rather an external one : other ligneages...
2- the social origin can play here too (selection) ...
3- the skulls linear mensurations described in the abstract are limited to the head height ; it is not the all mensurations... the volume ones could be linked only to the height ones, or not ? I noticed when I was young (1966-70), yet, that Americans presented seamingly (no mean for me to check it) higher skulls as a whole than the Europeans, even the northern ones, their forehead retreating slowly and the near horizontal summit of the head being shorter : in short, less « bombing » but higher forehead as a whole, more conic form of skull (they seamed to me too having bigger teeth as a whole : true teeths or prothesis?)- in Europe I rather notice what seams a diminution of head mensurations, at least when compared to body ones (particuliarly the height body ones and the feet ones)...Maybe the evolution in Europe and in the States are not the same ?
5-the difference between complete stature and femur growths strike me too: a very big difference : an internal evolution can explain a small margin but there !...
6- quality of sampling left on side, the quantity seams to me a bit scarce (1500 for all this period of 180 years is few for a so vaste land)
nevertheless, it remains a kind of truth behind these statistics - the changes in the way of living can surely modify some body internal proportions, but do'nt forget that new ethnic groups can send new proportions too! (here we state a global diminishing of legs compared to back lenght and head height -? maybe a link between back height and head height ? - all the way, concluding about time linked evolution is to be made very carefully