Re: Cost of natural selection revisited
- From: John Edser <edser@xxxxxxxxxxxxxx>
- Date: Wed, 18 Mar 2009 12:31:23 -0500 (EST)
Andrew Lang <fireforeg@xxxxxxxxx>
I am not clear about your definitions here. It could be that most
females are producing .5 offspring, a few fit ones are producing 3 and the
selection intensity would be log(3/.5) = log(6). It seems this could be
larger than what you call 'Nunney's maximum selection intensity' when R=10.
All females have the same number of offspring (except to the extent that
number is non-integer, so if fecundity is 2.33, most have 2 children but
every third female has 3). Not all children survive, but this is based
on genetic fitness and is the point of the exercise.
Selection intensity is the log of (children born) / (children that
survive). For a species to maintain its numbers (as the simulated ones
do) two children must survive per female on average, in the long term.
The genes of females that only have 0.5 surviving children will die out.
Those that have 3 surviving children will become the norm and population
pressure will reduce the number to 2.
JE:-
Hi Andrew,
The human genome project demonstrated that only handfuls of genes out of
about 20,000 or so human coding genes remain different between
individuals within any population of humans rendering "Haldane's
Dilemma" to the status of just a curious, gene centric artifact.
Haldane massively oversimplified to "additive", the fitness association
existing between any one coding gene to another within the same genome.
This oversimplification required an enormous genome to be able to code
for all the heritable traits known at the time. The tiny size of the
human genome surprised everybody for this reason. Empirically, the
fitness association between genes in the same genome remains NON
additive only requiring a small, compact highly geared genome, i.e. the
human genome that was actually observed. Haldane's oversimplification
which allowed independent gene fitnesses, was absolutely required to
allow Hamilton's proposed evolution of organism fitness altruism in
nature i.e. modern poly-centric Neo Darwinism.
Mendel proved that genes could independently segregate at meiosis. An
independent gene segregation does not allow Haldane and Fisher's
assumption of an independent gene fitness requiring the deletion of all
genetic epistasis within Neo Darwinian models. In nature fitness
epistatic groups of genes are selected not individual (selfish) genes.
In nature fitness was and remains a mono-centric, i.e. is not at all a
poly-centric concept. The biological sciences have always demonstrated
that the fitness of any one gene remains non additive (epistatic)
requiring a _minimal_ model of _two epistatic genes_ (two alleles
situated on different loci) to code for any one trait. Disregarding the
biological fact that reproductive fecundity is so very much higher than
the reproductive success of adults reproducing adults (infertile
individuals have to actually be raised to fertile adulthood before they
can possibly pass on their genes) what happens to the biological fitness
of a parent when one gene which allows 0.5 surviving children becomes
_epistatically_ combined with another gene which allows 3 surviving
children?
Regards,
John Edser
Independent Researcher
edser@xxxxxxxxxxxxxx
.
- Prev by Date: Re: Percolation theory
- Next by Date: Re: Is the paradigm of genetic code evolution wrong?
- Previous by thread: Re: Cost of natural selection revisited
- Next by thread: Re: Total Darwinian Fitness as a FALSIFIABLE FITNESS MAXIMAND
- Index(es):
Relevant Pages
|
