Soft versus Hard inheritance 
The concept of what determines the gender of a person is neither simple, nor as conclusive as on the surface it may appear. 
David Bainbridge , The X in Sex: How the X Chromosome Controls Our Lives.
derivation or evolution of the x and y mamallian chromosomes
"Yet the apparent primacy of the Y chromosomes still takes us no nearer to explaining how the sex chromosomes actually go about deciding the sex of a child."
p. 17.
| determinants | meaning | examples |
|---|---|---|
| genotype | ||
| phenotype | female |
male |
| hormones | estrogen |
androgen |
| proteins | Dax1 |
SRY |
| personal behavior | ||
| culture | feminine |
masculine |
| social conditioning |
"very occasionally, in perhaps 0.005 percent of babies, the rules of sex (gender) apparently flouted, leading to the birth of XX boys or XY girls. This sex reversal is a very rare event--so rare, that it is really quite surprising that it was ever discovered at all."
"a weakness in the the rule--a weakness that might help them understand how it (sex differentiation) worked."
p. 18.
• elements the basic determinants or fundamental aspects of any body of knowledge -- chromosomes, autosomes and alleles.
• factors the contributing features that comprise the context of a situation or must be understood to comprehend causes and effects -- proteins, meiosis, amino acids, base pairs or bp.
"So you can interpret the fact that human babies are initially made female, but can be modified into males, however you like. . . . Pehaps what all this is telling is is that the discovery of the mechanisms of sex determination has not altered the values we ascribe to the two sexes."
p. 33.
Sources
Richard Lewontin, The Triple Helix.
"The Unseen Genome: Beyond DNA" genetic vs. epigenetic considerations are discussed here.
Datse: 19 March 2008 & 2 August 2011.
Mayr | Thomas | Wilson | Hardin | Darwin | Margulis | Steingraber | Carr | Keller | Watson
