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Name: David O. 
Status: Other
Age: 40s
Location: N/A
Country: N/A
Date: January 2004


Question:
What comes first in living things a male or female?



Replies:
In humans, we all begin as females and early in uterine development the SRY gene on the y chromosomes is acitivated to push the fetus towards male charecteristics. If the sry gene is inactivated the fetus remains female...with a y chromosome...instructing us that the chromosomal makeup is not a certain indicater of sex.

PF


David,

The evolution of sex is a very complex topic and this forum would be hard placed to address it. The process of exchanging chromosome information can be seen clearly in the Monerans and Protists classification kingdoms, and the development of males and females evolves. The bottom line i suppose is that if you have females, you are implying that males are available. Females are certainly more important from a functioning reproductive discussion and we see some species only having female individuals.

There is a problem when one says that an human individual is female before the male SRY gene turns on to develop a male. The newly conceived male embryo is carrying the XY gene combination from fertilization and does not show the male characteristics until further along in the development. Here is a great explanation:

http://www.newton.dep.anl.gov/askasci/mole00/mole00074.htm

If one was to use logic to explain which was first, the female would have to win hands down biologically.

Steve Sample



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