On Tue, Nov 03, 2015 at 02:51:35PM -0800, Brent Meeker wrote: > > > On 11/3/2015 2:30 PM, Russell Standish wrote: > >On Tue, Nov 03, 2015 at 02:05:53PM -0800, Brent Meeker wrote: > >>>Biological theory says that sexual reproduction should halve the > >>>fitness of the organism as compared with asexual (or parthenogenetic) > >>>reproduction, so asexual reproduction should be the norm (as it is in > >>>bacteria). > >>But does it halve the reproductive chances of a gene; or does it > >>give it more chances of survival? > >> > >Halves it, because its a 50/50 lottery whether the gene from the > >female or the gene from the male is expressed in the offspring. > > But that's for one child. When sexual reproduction evolved the > number of offspring for most organisms was in the thousands, so a > given gene probably had many chances to combine with different genes > from the other gender. >
It still halves the fitness relative to asexual reproduction. What matters is relative fitness anyway (or differential fitness, as Lewontin puts it) - it doesn't matter if the absolute numbers are of order 1 or order thousands. The point is that when confronted which such damning evidence, a scientist will change er theory. A vast number of explanations for why sexual reproduction wins over asexual have been proposed, such as parasitism, such as the elimination of genetic errors due to operating above the error threshold (Mendel daemon hypothesis). These are being tested in ALife experiments, and in breeding experiments. Just that at present, there is no concensus, other than the original naive theory must be wrong. -- ---------------------------------------------------------------------------- Prof Russell Standish Phone 0425 253119 (mobile) Principal, High Performance Coders Visiting Professor of Mathematics [email protected] University of New South Wales http://www.hpcoders.com.au ---------------------------------------------------------------------------- -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
