Freethought & Rationalism Archive

cricket · 11-18-2002, 07:09 PM

Why is it that men are becoming smaller-jawed? I can see why they aren't penalized for it - like pz said, there are no fatal infections from impacted wisdom teeth now. But why, if strong jaws are manly, do men's jaws get smaller at all? Is it because it isn't a sex-linked trait?

Doubting Didymus · 11-18-2002, 07:55 PM

PZ was probably right the first time. Diet and culture can have a heck of an effect on the next generation. Certain practices cause certain features.

A distant relative of mine is quite insane, and she developed a strange phobia of food while she was pregnant. The madwoman refused to eat anything, and her children (now over 10 years old) have very strange bone structures. Thing is, she did it twice, with a space of about 3 years, and her second child also has extremely odd bones, but in exactly the same places as her sister. Obviously, there is a relatively direct, maybe even predictable, relationship between diet and other cultural practices, and phenotypes.

Zentraedi · 11-18-2002, 11:21 PM

Quote:

Originally posted by Camaban:
<strong>None serious.

we've been more or less static for at least 50k years (look at Australian Aborigines... the only two differences I've seen is skin colour, and slightly different nose shape (in general)).

what the fundy thinks is that evolution is something that *must* continually happen to *all* species. when there are many species that it's barely touched for tens of thousands, or even tens of millions of years.

I'm pretty sure that sharks are more or less unchanged, as an example. (more or less)

[ November 14, 2002: Message edited by: Camaban ]</strong>

What about the more pronouced features of the face like the protruding eye brows. Many people of african decent have wide noses and so do other apes? I've heard and have taken into beliefs that we may have spread civilization from africa, wouldn't it be reasonable that we all at one time had an appearence of an african. As to looking at African-Americans compared to native africans, do you see higher atheletic ability and more naturally toned bodies after selection in slavery for centuries?

I am interested as to what purpose there is to slant in the eyes of orientals. Do you notice that many people sexually prefer ones of their own race over others?

American Agnostic · 11-19-2002, 12:56 AM

The main cause of eveolution is natural selection but of course there are other causes like genetic drift in small population and what traits members of the opposite sex find attractive (there are some exaples of this in nature). All the evidence that we have seen so far leads us to conclude that evolution happens mostly amoung small groups of isolated individuals. The fact that (in the modernized world at least) humans have largely emliminated disease and starvation means that everyone's genes are being passed into the next generation and therefore natural selcestion isn't occuring. It's hard to see evolution taking place in the modernized world since there isn't really any natural selection going one. This will change however when genetic engineering becomes widely availible.

scigirl · 11-19-2002, 06:35 AM

Quote:

Originally posted by American Agnostic:
The fact that (in the modernized world at least) humans have largely emliminated disease and starvation

Well, not entirely eliminated.

Quote:

means that everyone's genes are being passed into the next generation and therefore natural selcestion isn't occuring.

I don't think this is entirely true. Check out the examples
<a href="http://iidb.org/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=58&t=001596" target="_blank">here</a> of beneficial human mutations.

I agree with you that raw, nasty selection as occured during 'primitive' man is not acting anymore. But selection is still happening - it's just hard to see where.

Mutant · 11-19-2002, 10:24 AM

Just a note about jaw size and such from the Price-Pottenger Nutrition Foundation site <a href="http://www.price-pottenger.org" target="_blank">http://www.price-pottenger.org</a> :

Quote:

Dr. Weston A. Price, a Cleveland dentist, has been called the "Charles Darwin of Nutrition." In his search for the causes of dental decay and physical degeneration that he observed in his dental practice, he turned from test tubes and microscopes to unstudied evidence among human beings. Dr. Price sought the factors responsible for fine teeth among the people who had them--the isolated primitives. The world became his laboratory. As he traveled, his findings led him to the belief that dental caries and deformed dental arches resulting in crowded, crooked teeth and unattractive appearance were merely a sign of physical degeneration, resulting from what he had suspected--nutritional deficiencies. Price traveled the world over in order to study isolated human groups, including sequestered villages in Switzerland, Gaelic communities in the Outer Hebrides, Eskimos and Indians of North America, Melanesian and Polynesian South Sea Islanders, African tribes, Australian Aborigines, New Zealand Maori and the Indians of South America. Wherever he went, Dr. Price found that beautiful straight teeth, freedom from decay, stalwart bodies, resistance to disease and fine characters were typical of primitives on their traditional diets, rich in essential food factors.

He wrote a book about his evidence and conclusions in the book Nutrition and Physical Degeneration. Anyway, though evolutionary forces may be work, I don't think it is fair to assert that our current condition is a result of some evolutionary 'slide'.

Mutant

Doubting Didymus · 11-19-2002, 02:19 PM

Excellent quote, mutant.

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11-18-2002, 07:09 PM	#31
cricket Veteran Member Join Date: Aug 2001 Location: St Louis MO USA Posts: 1,188	Why is it that men are becoming smaller-jawed? I can see why they aren't penalized for it - like pz said, there are no fatal infections from impacted wisdom teeth now. But why, if strong jaws are manly, do men's jaws get smaller at all? Is it because it isn't a sex-linked trait?

11-18-2002, 07:55 PM	#32
Doubting Didymus Veteran Member Join Date: Jul 2002 Location: East Coast. Australia. Posts: 5,455	PZ was probably right the first time. Diet and culture can have a heck of an effect on the next generation. Certain practices cause certain features. A distant relative of mine is quite insane, and she developed a strange phobia of food while she was pregnant. The madwoman refused to eat anything, and her children (now over 10 years old) have very strange bone structures. Thing is, she did it twice, with a space of about 3 years, and her second child also has extremely odd bones, but in exactly the same places as her sister. Obviously, there is a relatively direct, maybe even predictable, relationship between diet and other cultural practices, and phenotypes.

11-19-2002, 12:56 AM	#34
American Agnostic Junior Member Join Date: Sep 2002 Location: CA, USA Posts: 56	The main cause of eveolution is natural selection but of course there are other causes like genetic drift in small population and what traits members of the opposite sex find attractive (there are some exaples of this in nature). All the evidence that we have seen so far leads us to conclude that evolution happens mostly amoung small groups of isolated individuals. The fact that (in the modernized world at least) humans have largely emliminated disease and starvation means that everyone's genes are being passed into the next generation and therefore natural selcestion isn't occuring. It's hard to see evolution taking place in the modernized world since there isn't really any natural selection going one. This will change however when genetic engineering becomes widely availible.

11-19-2002, 02:19 PM	#37
Doubting Didymus Veteran Member Join Date: Jul 2002 Location: East Coast. Australia. Posts: 5,455	Excellent quote, mutant.

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