Re: Hemophilia

[John Jacobus <crispy_bird@YAHOO.COM>]

Or maybe there is no real "direction" along the

evolutionary pathway.



--- "MacLellan, Jay" <jay.maclellan@PNL.GOV> wrote:

> Re:  "I would also say that not all negative

> mutations are selected

> against survival.  There are a number of genetic

> diseases that do not

> improve the species, e.g. hemophilia, but are still

> present and are

> passed along.  It escapes me what was the

> evolutionary or genetic

> process that allowed it to exist in humans."

> 

> A mutation does not have to be beneficial to exist

> in the human gene

> pool.  All that is required is that it is not fatal

> to the individual

> until after successful reproduction.  In the case of

> hemophilia, it is a

> recessive trait that can be passed through a

> generation without being

> expressed.  According to my medical dictionary, "It

> is a sex-linked

> hereditary trait, being transmitted by normal

> heterozygous females who

> carry the recessive gene.  It occurs almost

> exclusively in males."  I

> don't believe there are any more evolutionary

> pressures favoring its

> existence, than there are evolutionary pressures in

> favor of diabetes.

> It all comes down to whether you believe our species

> is evolving toward

> perfection, or away from it. 

> 

> . . .



=====

+++++++++++++++++++

"I have sworn upon the altar of God, eternal hostility against every form of tyranny over the mind of man."

Thomas Jefferson



-- John

John Jacobus, MS

Certified Health Physicist

e-mail:  crispy_bird@yahoo.com



__________________________________

Do you Yahoo!?

Yahoo! SiteBuilder - Free web site building tool. Try it!

http://webhosting.yahoo.com/ps/sb/

************************************************************************

You are currently subscribed to the Radsafe mailing list. To

unsubscribe, send an e-mail to Majordomo@list.vanderbilt.edu  Put the

text "unsubscribe radsafe" (no quote marks) in the body of the e-mail,

with no subject line. You can view the Radsafe archives at

http://www.vanderbilt.edu/radsafe/