Re: Inbreeding and accelerated evolution?

[frank bliss <frank@blissnet.com>]

I think one can be safe by saying, the larger the litters and the more 
frequent the "littering", the less damage from inbreeding that will 
occur in a bottlenecked population.  (the more they muck, the better 
their luck!) Double lethal recessive and damaging genes are naturally 
selected against so large numbers tend to muffle the expression and 
thus, reproduction of those genes in the population soon after the 
bottleneck. These results are from the dilution of the gene pool by 
less lethal combinations present because of a large number of 
individuals resultant from large litters (more rolls of the dice with 
the present genetic material).   Additionally, larger animals tend to 
have "smaller litters" (except egg layers perhaps) and visa versa for 
smaller animals.  Larger animals also have a longer developmental time 
before minimum breeding age thus there is a generational bias toward 
smaller animals having more variation within an initially equal 
bottlenecked population.  I believe that genetic drift should occur 
more frequently from a smaller initial population eventually leading to 
a punctuated equilibrium with the environment or directly to speciation 
depending on the selective circumstances. The "founder effect" is very 
relevant here.  Just look at the Amish in Pennsylvania (an isolated, 
small population) and the resultant effects such as dwarfism and 
polydactyly. Certainly this held true in the distant past as well ie.  
Uniformitarianism.
Frank Bliss
MS Biostratigraphy
Weston, Wyoming.