Naked Science Forum
Life Sciences => Physiology & Medicine => Topic started by: ROBERT on 31/01/2006 16:15:14
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"" British Dental Journal (2006); 200, 33-37. doi: 10.1038/sj.bdj.4813122
A cephalometric comparison of skulls from the fourteenth, sixteenth and twentieth centuries.
Objectives: To evaluate changes in the size and shape of the skull and jaws in British populations between the thirteenth and twentieth centuries.
Method: Lateral cephalometric radiograms were obtained from skulls of three groups of subjects: 30 skulls were from the remains of those who died in the London Black Death epidemic of 1348, 54 skulls were recovered from the wreck of the Mary Rose which sank in 1545 and 31 skulls were representative of modern cephalometric values.
Results: Horizontal measurements in the base of the anterior cranial fossa and in the maxillary complex were greater in the modern group than in the medieval skulls. Cranial vault measurements were significantly higher (P = 0.000) in the twentieth century skulls, especially in the anterior cranial fossa.
Conclusion: Results suggest that our medieval ancestors had more prominent faces and smaller cranial vaults than modern man.
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http://www.nature.com/bdj/journal/v200/n1/abs/4813122a.html
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Could these finer features be due to the changing status of females in British society over this period ?
Studies have shown that on average women have a preference for males with finer features:-
http://calvin.st-andrews.ac.uk/external_relations/news_article.cfm?reference=409
From medieval times to present day, British women have gone from being "chattel",
(property of males), to having rights equal to that of males.
So during this period women would have a increasing say in their choice of husband and this could account for the refinement of human features over this comparatively short period of time (650 years - 30 generations).
Or to put it another way, medieval humans had coarser, more prominent features because the women of that period had less freedom to choose who was the father of their children.
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Certainly, one can imagine female choice to be a factor, but not so much because females have more choice than in the past, but maybe because masculinity is less highly prized (even by women) than it was in the past. The modern world is not as violent as the past, so maybe those aspects of male face that related to violence were more highly prized in the past than today.
Incidentally, if what one sees is a feminisation of the male face over that time, one could ask whether that is mere coincidence that in recent years people have been concerned about the reduced fertility of males in the population.
The question one must ask is how broad a spectrum of classes of people were studied?
The skulls from the Mary Rose would have been predominantly male, and predominantly a class of person who was well suited to military service.
What class of skull was studies in the 1348 sample? Was there a sufficient study of both male and female, or is this purely a study of male skulls? Given the lesser degree of both social and geographic mobility in 14th century England, how similar is the family background of those studied? In some areas of the country, even today, if one took sample from a single cemetery, one could easily come to the conclusion that the entire country was populated by Pakistanis, or in a neighbouring cemetery, that the entire country was populated by Jews.
I find it very believable that the human body has changed over time, but I am also aware that studying two localised points in space and time does not give you a broad spectrum of the population. They have done is taken 30 skulls from 1348, and 54 from 1545 – scarcely what one might regard as a statistically significant sample size to determine what the national average was.
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quote:
Originally posted by another_someone
The question one must ask is how broad a spectrum of classes of people were studied?
The skulls from the Mary Rose would have been predominantly male, and predominantly a class of person who was well suited to military service.
You are quite right about the military's bias for masculine features: studies have shown that having an ultra-masculine ("dominant") face has a greater influence on a soldier's final rank than his academic ability:-
""facial dominance -- measured from cadet portraits taken 20+ years earlier -- significantly predicted promotion to the highest ranks -- to the various levels of general officer. Having a dominant face was an advantage in reaching the top (Mazur and Mueller 1996; Mueller and Mazur 1996).""
http://cogprints.org/631/00/Facdom.html
I don't know if the BDJ study used the skulls of modern (20th century) military personnel in their study to ensure a fair comparison.
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Even comparing modern military personel may not be a good comparison as the modern military involves a lot more button pressing and less axe wielding than it did in medevil times, but I guess there is still a self selection going on.
What effect does malnutrition have on people's faces? As I guess that most people in the middle ages were malnourished in some way, apart from anything else as they were much shorter than we are today.
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quote:
Originally posted by daveshorts
What effect does malnutrition have on people's faces? As I guess that most people in the middle ages were malnourished in some way, apart from anything else as they were much shorter than we are today.
Malnourishment aside, they would have been differently nourished. It could even be that they might be overnourished on some nutrients, just as we are overnourished on some (but possibly different) nutrients.
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I cannot see how a dietary deficiency could enlarge bone structure. Diseases such a syphilis and tuberculosis, (common in medieval times), can effect bone. However diseased specimens would have been excluded from the study.
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quote:
Originally posted by ROBERT
I cannot see how a dietary deficiency could enlarge bone structure. Diseases such a syphilis and tuberculosis, (common in medieval times), can effect bone. However diseased specimens would have been excluded from the study.
I am very wary about terms such as “would have been”. If you had simply said “have been”, without the qualification, I would have been more confident.
Could not delayed puberty cause increased bone size – although I would expect that more to manifest itself in increase size of long bones – which clearly is not the case here.
The other question is, are we talking about changes is absolute size, or relative size (do we know that they measured actually more bone, or merely more bone in relation to the rest of the skull, which may have been smaller)? After all, they only drew the conclusion that the shape of the face was different, and shape is different from size.
Finally, could not some of it have been due to different strains put upon the bones due to the nature of the food that was chewed?