Debrachycephalization in Europeans

[Polak]

I started this thread because I would like to investigate this fascinating phenomenon more closely.

I'll be adding material to this thread regularly, and I would like other members to do so as well. The only thing I ask is that the material be relatively recent (post WWII), and scientifically sound (no info from places like the nordish preservation society of whatever those jokers call themselves).

Here's the first article, which some of you may have seen on Skadi...

Brachycephalization in Japan has ceased

Makiko Kouchi *
Human-Environment System Department, National Institute of Bioscience and Human Technology, Tsukuba, Ibaraki 305-8566, Japan

email: Makiko Kouchi (kouchi@nibh.go.jp)

*Correspondence to Makiko Kouchi, Human-Environment System Department, National Institute of Bioscience and Human Technology, Higashi 1-1, Tsukuba, Ibaraki 305-8566. Japan

Keywords
debrachycephalization; facial flatness; height; secular change


Abstract
Somatometric data are presented which show that the rapid brachycephalization in Japan has recently ceased. The causes of brachycephalization are investigated in relation to the secular change in height. Increases in head breadth have been the main cause of brachycephalization, and its pattern of secular change is very similar to that in height. Associations between head breadth, height, and year of birth were examined by partial correlation coefficients and through a comparison of students and the general population. Brachycephalization is thought to result from increases in the growth rate for head breadth caused by improvements in nutritional levels, as seen in increases in height. Increases in height over the last 100 years have been accompanied by brachycephalization in Japanese and Koreans, but by debrachycephalization in many European populations. Increases in lateral growth in Asian heads may be related to the facial flatness which is characteristic to northern Mongoloid populations. Am J Phys Anthropol 112:339-347, 2000. © 2000 Wiley-Liss, Inc.

[Awar]

You can notice it here in Serbia. Most old people are brachycephalic, while the young people are mesocephalic. The old people are rarely taller than 180cm, while the younger generations are 185cm on average etc.

[Antiquarian]

Originally Posted by Polak

I started this thread because I would like to investigate this fascinating phenomenon more closely.

I'll be adding material to this thread regularly, and I would like other members to do so as well. The only thing I ask is that the material be relatively recent (post WWII), and scientifically sound (no info from places like the nordish preservation society of whatever those jokers call themselves).

Here's the first article, which some of you may have seen on Skadi...

The reasons for this shift in cranial index arent entirely known. Here is what Jantz and Owsley had to say about this in "Reply to Van Vark et al. : Is European Upper Paleolithic Cranial Morphology a Useful Analogy for Early Americans?" in American Journal of Physical Anthropology.

"The model by Carlson and Van Gerven (1977) has often been cited in support of the idea that the brachycephalization seen in many human populations results from functional response to food producing (see also Larsen, 1997). This model was developed on Nubian populations, and depends to a considerable extent on local continuity, an idea with little empirical support. The amount of time between their Mesolithic and Neolithic samples is roughly 8,000 years. Turner and Markowitz (1990) argued that population replacement is a more likely explanation of the dental evidence.

In Europe, the most intense brachycephalization occurred during the Middle Ages, well after the masticatory changes associated with food producing were in place (Necrasov, 1974). Recent changes in America and Europe, surely populations with the least challenged masticatory systems in the world, are now proceeding in the opposite direction (Jantz and Meadows Jantz, 2000; Jantz, 2001; Zellner et al., 1998). The model by Boldsen (2000) of selection with a demographic transition associated with the spread of urban communities demonstrates that change in head width can occur rapidly. This change does not necessarily obscure relationships.

It is fashionable now to minimize cranial morphology as a source of information about past populations. We can readily acknowledge that we are a long way from understanding the causes which underlie specific changes in cranial morphology. Some of the variation, possibly even a majority, may be neutral variation (Relethford, 1994; Relethford and Harpending, 1994), and selection may have played a role, at least periodically. Although phenotypic plasticity is often cited as a mechanism for cranial response, we are unaware of any evidence that can be used to demonstrate a consistent response to a particular environmental agent, with the possible exception of some gracilization as a response to reduced masticatory stress (Lahr and Wright, 1996)"

[Nadvojvoda Janez Kranjski]

Another question are the birth rates among the social classes, as in some countries the sub-races tend to be socially stratified.

[Antiquarian]

Originally Posted by Janez

Another question are the birth rates among the social classes, as in some countries the sub-races tend to be socially stratified.

Because of the differences in diet that are associaed with social stratification, this subject is possibly relevant to functional differences between skulls from different classes, as well as to the preservation of phenotypes related to castes. I think Jantz and Owsley have good reason to question the idea that changes in cranial index always have a consistent cause, so it should be remembered that this is speculative. In Europe broad frontals mignt be from a neanderthaloid source and continuous to certain Europeans, through the Upper Paleolithic European moderns.

[Polak]

Originally Posted by Antiquarian

Because of the differences in diet that are associaed with social stratification, this subject is possibly relevant to functional differences between skulls from different classes, as well as to the preservation of phenotypes related to castes. I think Jantz and Owsley have good reason to question the idea that changes in cranial index always have a consistent cause, so it should be remembered that this is speculative. In Europe broad frontals mignt be from a neanderthaloid source and continuous to certain Europeans, through the Upper Paleolithic European moderns.

Indeed, it seems phenotypes are, to a large degree, affected by enviornmental conditions. In the upper classes, gracilized types always seem to be fairly common.

I guess it's a question of gene expression. Genes will express themselves differently in different conditions...but you need the genes to create, say, a corded, in the first place. Because it doesn't matter if someone grows up in a well to do home, if they don't carry any corded or med type lineages.

But from what is happening, it seems that many Europeans carry these genes. That's why Serbs, Poles, Czechs, Germans, and many others are getting longer headed...and their phenotypes are different from one generation to another. Even some of the old anthropologists noticed this.

[Nadvojvoda Janez Kranjski]

Funny, I remember that when I was a kid, I thought that old people have rather round skulls and youths have longer skulls, so that this was a question of age. Seriously. This is a trend I have observed.

[Antiquarian]

According to Beals, Smith annd Dodd, cold climate creates a shift in cranial shape, which contributes to an increased cranial volume and brachycephalisation. They support that and cranial index shouldnt be used in racial typology.

[Graeme]

How much time is necessary for a shift in cranial shape? I know many Maltese people who are descended from Maltese people who are decidely round headed or even UP. Surely they should be slightly built long heads in their Mediterranean climate.

[Antiquarian]

Originally Posted by Graeme

How much time is necessary for a shift in cranial shape? I know many Maltese people who are descended from Maltese people who are decidely round headed or even UP. Surely they should be slightly built long heads in their Mediterranean climate.

I dont understand why youre associating robusticity with cranial index, but the authors didnt say the rule was absolute, they only said it was important.

[Polak]

Originally Posted by Graeme

How much time is necessary for a shift in cranial shape? I know many Maltese people who are descended from Maltese people who are decidely round headed or even UP. Surely they should be slightly built long heads in their Mediterranean climate.

Not very long.

Apparently, in Eastern Europe, a change of 2 or three, or even more, Cephalic Index points has taken place since WWII.

The CI has fallen, by the way.

[Polak]

This article claims that some south Asians are becoming more brachycephalic.

[Graeme]

Do you have any evidence or data from other parts of Europe, other than in eastern Europe? The lengthening of the skull may be eastern European specific. Does it follow any climatic line? I remember that height used to be tallest in those parts of Europe where the temperature line was 0 deg Celius. Of course that could have been coincidental.

[Dr. Solar Wolff]

What all of you guys are saying is that head shape is very plastic in sapiens. There are so many factors involved that it is almost impossible to use it as a basis for tracing ancestry. I believe that even a dentist can influence CI with he straightens the teeth of a child. This changes the bit, length of the dental archade and so influences the muscle attachement on the skull. To some extent the bone responds to stress and develops in response to it. I suspect that this changing of the teeth influences the adult CI.

[Graeme]

Cephalic Index is not important in making comparisons of remains from many generations back or from skeletal remains. The hard part is that the sub racial divisions of caucasians is based on the shape of the skull. What is Nordid or Mediterranid or Alpinid without the shape of the skull?

[Polak]

Originally Posted by Graeme

Cephalic Index is not important in making comparisons of remains from many generations back or from skeletal remains. The hard part is that the sub racial divisions of caucasians is based on the shape of the skull. What is Nordid or Mediterranid or Alpinid without the shape of the skull?

Yeah, but show me a serious report from the past 20 years that actually mentions European sub-races.

I think that human races do exist. In other words, there are several sub-species just like in most other animals.

However, I don't believe in further sub-dividing sub-species into sub-sub-species. I've never heard of scientists dividing any other animal on this planet into sub-sub-species. Why should humans be any different? Can anyone here explain that to me?

Sure, it's fun playing Carleton Coon on internet forums, but let's be serious, dividing humans into sub-races is a silly game for many reasons.

The Cephalic indes changes from generation to generation if the right stimuli is present. So does body height and build.

IMO facial features and pigmentation are clearly influenced by genes, and they remain more constant over time.

So, for example, in Poland young people are now longer and narrower headed, and much taller. But the most common hair color in Poland remians a dark ash blond, and the eyes are most commonly greyish blue. Facial features are also still characteristically Polish, despite the changes in cranial shape.

But does this mean there is a Polish sub-race within the Caucasian race? No, that's just regional variation.

If Poland was left isolated for another 50,000 years, then yeah, there might be a Polish race...but not right now.

Btw, where is the Alpine territory in Europe these days? Can anyone tell me?

The Swiss, Austrians, Czechs and Hungarians are as tall as North West Europeans nowdays...and almost as long headed.

In fact, Czechs and Hungarians are taller than the British now.


Here's a report I would like to get my hands on. If anyone has it, please let me know ASAP.



Influence of positioning of infants on long-term changes of cephalic dimensions.

Paulova M, Blaha P, Vignerova J, Riedlova J.

Faculty of Science, Charles University, Prague, Czech Republic.

The submitted investigation describes long-term changes of 3 main cephalic dimensions (head circumference, maximal length and maximal width of the head) and analyses the possible influence of positioning of infants after birth (prone, supine and side sleeping position) on these changes. Information about children aged 6 months to 3.99 years, where the need of up-to-date data is greatest, were collected as part of an extensive anthropological survey implemented in 1995 to 1997 in the entire Czech Republic. The authors confirmed the trend of debrachycephalization, which is manifested by a statistically significant increase of the maximal length of the head and a statistically significant decrease of the maximal width of the head, as compared with children examined in the anthropological survey in 1956 to 1962 (1). These changes were established in the group of boys (200 boys) as well as in the group of girls (167 girls). The differences of the magnitude of long-term changes between boys and girls were not significant. Evaluation of the long-term changes of the head circumference in the entire group of 366 children aged 0.5-3.99 years (the head circumference of one girl was not measured) revealed a statistically significant increase of this dimension. During the period from 1956/62 till 1996, the influence of positioning on the magnitude of long-term changes of head circumference was not proved. We can say the same about the maximal length of the head of boys and girls and about the maximal width of the head of girls. Only between three differently positioned groups of boys (prone, side, supine) statistically significant differences in the magnitude of long-term changes of the maximal width of the head were found (p < 0.05). Highly significant changes of the maximum width and maximum length of the head occurred as compared with a reference group in all three groups of positioning of infants and in both sexes. The trend of debrachycephalization seems to be thus a more potent factor, which affects long-term changes in the shape of the head, then the predominating sleeping position during the first months after birth. This conclusion is supported by the persisting trend of debrachycephalization, although the supine position is now preferred.

[Nadvojvoda Janez Kranjski]

(probably nothing new)

Secular change in body height and cephalic index of Croatian medical students (University of Rijeka).

Buretic-Tomljanovic A, Ristic S, Brajenovic-Milic B, Ostojic S, Gombac E, Kapovic M.

Department of Biology, University of Rijeka School of Medicine, 51 000 Rijeka, Croatia. alena@medri.hr

An investigation of body height and cephalic measurements was performed among five groups of first-year medical students of the University of Rijeka School of Medicine (Rijeka, Croatia). Body height and different cephalic measurements showed normal distribution, both in male and female students. Differences between measured variables were statistically analyzed by ANOVA. No significant difference with regard to year of birth was found in either males or females. The cephalic index showed no statistically significant difference between sexes or with regard to body height, while head breadth and length correlated significantly with birth year and body height, both in males and females. Head breadth decreased within the study period, while head length increased. Results were compared with those of similar studies from the mid-20th century. Student's t-test showed a significant change of cephalic indices and other head measurements, but not of body height, in males. The frequency difference between various head shapes was tested using the chi-square test. A significant increase of dolichocephalic and mesocephalic and a significant decrease of brachycephalic head shape were found in both sexes. These results suggest a continuity of the debrachycephalization process observed in our population at the past midcentury. Copyright 2003 Wiley-Liss, Inc.

PMID: 14669240 [PubMed - indexed for MEDLINE]

http://www.ncbi.nlm.nih.gov/entrez/q...&dopt=Abstract

[Nadvojvoda Janez Kranjski]

[Is head size modified by environmental factors?]

[Article in German]

Jaeger U, Zellner K, Kromeyer-Hauschild K, Finke L, Bruchhaus H.

Institut fur Humangenetik und Anthropologie der Friedrich-Schiller-Universitat Jena.

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.

PMID: 9850630 [PubMed - indexed for MEDLINE]

http://www.ncbi.nlm.nih.gov/entrez/q...t_uids=9850630

[Nadvojvoda Janez Kranjski]

[The phenomenon of debrachycephalization in Jena school children]

[Article in German]

Zellner K, Jaeger U, Kromeyer-Hauschild K.

Institut fur Humangenetik und Anthropologie der Friedrich-Schiller-Universitat Jena.

Head measurements are performed within the anthropological investigations of school children from Jena (Germany) since more than 5 decades (1944-1995). Here we report on secular changes of the head length, the head breadth and the cephalic index. The head circumference, measured in 1985 and in 1995, is included in the analysis. Head length and head breadth show a contrary development over the whole period: the average length of the head increases between the consecutive investigations, whereas the breadth of the head decreases continuously between the separate investigations. As a consequence the cephalic index decreases in boys and girls for about 8 units since 1944. In this way a secular change of the shape of the head in the sense of debrachycepha