To be honest the assertion that previously seperate 'fit' populations were added was too ridiculous to contemplate - it would so obviously invalidate the results.<quoted text>
Glad you read it closely enough to see that I was right.
The degraded populations were "separately expanded and maintained at large population sizes". SEPARATELY. No admixture with healthy outside populations.
Outside populations were also included in the study (revived from cryogenic freezing, but kept separate, meaning that improved fitness in the degraded group could ONLY come from the genetic material already within the group.
To repeat: Accumulated loss of fitness due to the accumulation of deleterious mutations in the absence of natural selection is reversible when natural selection is reintroduced!
There is no way around it. Sanford's hypothesis is falsified.
why would anyone believe that this is what happened?