There are important genes not having to do with sex determination that are carried on the X chromosome. If one is bad, a female has a spare X gene that may carry a good gene to offset the bad one. In males, there is only one X so if they have a bad gene on the X chromosome, it'll show up. It is interesting to note that humans who are missing one sex chromosome are always female (Turner's Syndrome). There are no known cases of humans with only a Y chromosome and no X. I suspect that there must be genes on the X chromosome that are necessary for survival. All the best, Susan Cochran
----- Original Message ----- From: "Susan A. Schlenger" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Sunday, December 23, 2001 11:14 AM Subject: Re: [CKCS-L] Female puppies > Hi, Myra, > Would that be due to the better development of lung surfactant in > premie girls? I wonder if it is the same in canines.........? > > Suze > > Myra Savant wrote: > > > > I don't know about puppies, but I know that years ago when I worked Labor > > Delivery, we were always very relieved if our premies were little girls > > because they consistently did so much better than our little premie boys. > > This was very well documented at the time and accepted throughout the > > industry as being standard. The girls were healthier and more likely to > > pull through. Myra Savant > > > > >From: Sheena Stevens <[EMAIL PROTECTED]> > > >Reply-To: The Cavalier King Charles Spaniel List > > ><[EMAIL PROTECTED]> > > >To: [EMAIL PROTECTED] > > >Subject: Re: [CKCS-L] Female puppies > > >Date: Sun, 23 Dec 2001 11:21:24 +0000 > > > > > >Don't laugh, I did a paper on this when I was at LSE (although for humans). > > >The double X chromosome makes the female more stable, and female neonates > > >are better advanced physically at time of birth, therefore more likely to > > >survive. The uterus has a predisposition to form a female foetus and if > > >the > > >signal isn't received by a certain week (sorry, can't remember it all) will > > >form a female. More males are conceived overall, but more lost due to > > >spontaneous abortion, etc. There are always more males born, more males > > >lost during first few weeks of infancy, and the m/f ratio rises during > > >times > > >of trouble with more males being born (seriously)after/during wars, etc. > > > > > >There are various theories about acid/alkaline mediums in the uterus to aid > > >gender selection, and various foods ... > > > > > >I myself am the result of an extremely cold winter ... > > > > > >Best > > > > > >Sheena > > > > > > > > >Sheena Stevens > > >Kilnshena Kavaliers > > >Devon, UK > > >[EMAIL PROTECTED] > > > > > > > > >_________________________________________________________________ > > >Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp. > > > > > >========================================================= > > >"Magic Commands": > > >to stop receiving mail for awhile, click here and send the email: > > >mailto:[EMAIL PROTECTED]?body=SET%20CKCS-L%20NOMAIL > > >to start it up gain click here: > > >mailto:[EMAIL PROTECTED]?body=SET%20CKCS-L%20MAIL > > > > > >E-mail [EMAIL PROTECTED] for assistance. > > >Search the Archives... http://apple.ease.lsoft.com/archives/ckcs-l.html > > > > > >All e-mail sent through CKCS-L is Copyright 1999 by its original author. > > > > _________________________________________________________________ > > MSN Photos is the easiest way to share and print your photos: > > http://photos.msn.com/support/worldwide.aspx > > > > ========================================================= > > "Magic Commands": > > to stop receiving mail for awhile, click here and send the email: > > mailto:[EMAIL PROTECTED]?body=SET%20CKCS-L%20NOMAIL > > to start it up gain click here: > > mailto:[EMAIL PROTECTED]?body=SET%20CKCS-L%20MAIL > > > > E-mail [EMAIL PROTECTED] for assistance. > > Search the Archives... http://apple.ease.lsoft.com/archives/ckcs-l.html > > > > All e-mail sent through CKCS-L is Copyright 1999 by its original author. > > -- > Suze at Llawen Cavaliers > "...I have seen that in any great undertaking it is not enough for a man > to depend simply upon himself." -Isna Ia-wica > "Thought comes before speech" Luther Standing Bear > > ========================================================= > "Magic Commands": > to stop receiving mail for awhile, click here and send the email: > mailto:[EMAIL PROTECTED]?body=SET%20CKCS-L%20NOMAIL > to start it up gain click here: > mailto:[EMAIL PROTECTED]?body=SET%20CKCS-L%20MAIL > > E-mail [EMAIL PROTECTED] for assistance. > Search the Archives... http://apple.ease.lsoft.com/archives/ckcs-l.html > > All e-mail sent through CKCS-L is Copyright 1999 by its original author. ========================================================= "Magic Commands": to stop receiving mail for awhile, click here and send the email: mailto:[EMAIL PROTECTED]?body=SET%20CKCS-L%20NOMAIL to start it up gain click here: mailto:[EMAIL PROTECTED]?body=SET%20CKCS-L%20MAIL E-mail [EMAIL PROTECTED] for assistance. Search the Archives... http://apple.ease.lsoft.com/archives/ckcs-l.html All e-mail sent through CKCS-L is Copyright 1999 by its original author.
