[PW] Re: ?redheads percentage

[Peter Macinnis]

That fallacy about recessive genes dying out or varying their proportion 
in some way was shot down by Godfrey Hardy in 1908.

Somebody, probably a surgeon, referred to by Hardy as "Mr Udney Yule" 
had written in the _Proceedings of the Royal Society of Medicine_ in 
early 1908 that dominant characters would increase in numbers, replacing 
recessive characters, until the ratio of dominant type to recessive type 
was three to one.  Mendel was rediscovered in about 1900: Yule was 
writing eight years later, and still hadn't got it right. Hardy saw 
straight away that Yule's suggestion was nonsense, and wrote that "A 
little mathematics of the multiplication-table type is enough . . . ".

In short, said Hardy, the ratio of dominant and recessive genes found in 
one generation ought to be repeated in the next, unchanged. The dominant 
genes don't get more common. He recognised this might change if one of 
the genes influenced fertility, but he made no suggestion that there 
might be changes brought about by selection.

The principle is now enshrined in one of the few eponymous laws of 
science promulgated in the 20th century, the Hardy-Weinberg Law, 
celebrating G. W. Hardy and Wilhelm Weinberg.

My researches have turned up two possible candidates for "Udney Yule": 
one George Udney Yule was in the Bengal Civil Service in the 19th 
century, and shot some 400 tigers, but the correct target appears to be 
somebody who lived from 1871 to 1954, and wrote a textbook on 
statistics. Whoever he was, whatever he was, our Udney Yule had an 
unsound grasp on genetics, at least in the early 20th century.  Well, it 
was early days in the field of genetics, wasn't it?

peter macinnis


Dayle Irwin wrote:
> Wow!  I hope this dire prediction doesn't come true. I am of Scottish
> descent, and really look it, including the very pale skin.
> I was born a redhead, a deep copper color rather like a new penny.
> But it faded out to more of a strawberry blond (although everyone 
> predicted that my hair color was so deep that it would go brown later) 
> during my pregnancy in my late twenties.  I was devastated.  
> However, my son got the color.  That helped a bit.  
> But neither of his daughters got it, so I can see how it could
> fade out in the world, too.  
> How sad.  
> A world without redheads would definitely lack color!
> 
> Dayle Irwin
> decatur68 at earthlink.net
> 
> 
> 
> 
>>[Original Message]
>>From: Charles Early <cearly at pop200.gsfc.nasa.gov>
>>To: <list at project-wombat.org>
>>Date: 3/10/2006 3:46:01 PM
>>Subject: [PW] Re: ?redheads percentage
>>
>>Last year there were news stories about a prediction by the Oxford Hair 
>>Foundation that redheads would be extinct by the end of this century. 
> 
> The 
> 
>>foundation estimated that only 4% of the world's population carry the
> 
> gene 
> 
>>for red hair, and it's a recessive gene, so people will have red hair
> 
> only 
> 
>>if both their parents carried the gene. Therefore, it's also true that
> 
> the 
> 
>>number of redheads in the world today must be less then 4% of the 
>>population.  Because of globalization, the gene will be diluted by 
>>intermarriage with groups lacking the gene and redheads will become even 
>>rarer (but not quite extinct:  with completely random matches  4% of 4%,
> 
> or 
> 
>>0.16%, of the world population would still have red hair--my editorial 
>>comment).
>>
>>The Oxford Hair Foundation has transferred all of its information to the 
>>P&G Beauty website 
>>(http://www.pgbeautyscience.com/en_UK/main/index_en.html) and that site's 
>>link to "Scientific Publications" isn't working, so I can't find the
> 
> source 
> 
>>for their estimate of the gene frequency.
>>
>>According to Wikipedia, about 2-3% of the U.S. population have red hair.
>>
>>At 11:52 AM 3/10/2006, you wrote:
>>
>>>A statistic that I have seen "around" is that less than 1 percent of the
>>>human race are redheads, except sometimes it is less than 1 percent of
>>>the population of the United States are redheads. I can't find that
>>>demographic in any government statistical source or from a scholarly
>>>source in several periodical databases. Where did this "fact" originate?
>>>What is an accurate demographic for redheads? Who compiles such
> 
> statistics?

-- 

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