OK, but what are the plausible heredity rules that preserve the relevant ratios in the steady state (i.e., without the termination rule)? (By "plausible", I mean conforming to standard human genome kinds of things--gender determination from XvY sperm, mitochondrial genome from mother, mother-father gene pairs for everything else.) Presumably, the children of the two kinds of couples are genetically different in some way. What are the coupling rules that preserve the ratios, remembering that you need a boy to couple with a girl, and we probably need to assume monogamy to apply the "stop at first boy" rule (although it could be applied to just one parent, taking just that parent out of the reproducing pool). Assume a finite population, so at least some "interracial" coupling is required in the steady state. --ms On Thursday 08 July 2010 10:00:13 Andy Latto wrote:
On Thu, Jul 8, 2010 at 8:08 AM, Mike Speciner <ms@alum.mit.edu> wrote:
Another question is, are there plausible rules of heredity and reproduction that would alter the Boy/Girl ratio if "families" ceased reproducing at the first boy, but not if they stopped randomly?
Suppose different couples have different chances of having a boy. For example, half the couples have a 75% chance that each of their children is a boy, while half the couples have a 25% chance that each of their children is a boy. Now a "stop at the first boy" rule will change the ratio in the population.
Andy
_______________________________________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun