More than 50 years of research, dozens of papers and several books by multiple researchers from different countries have resulted from the original Russian fox "star gene" experiments. The results were duplicated in red fox, mink, artic fox, and in other carnivores and several rodent species. The hypothesis is that selecting for tameness alone triggers the process that ultimately leads to domestication. I could document the process, but since your question was regarding the regression to the means aspect, in order to save time and space, I'll hold off until some other time. If I understand regression to the means correctly (I am not a math major), each generation of offspring would move towards the mean (tameness), BUT they would show LESS overall tameness than the maximum shown in the initial generation. For example, if only tall parents are bred, it results in tall offspring, but with a mean shorter than the original parents. In domestication, the overall degree of tameness is increased, rather than finding that some some animals become tamer, while others become slightly less tame. This shows the population is not being compressed towards a mean, but the frequency of expression is being skewed towards a single end of the bell curve. The way I understand it, if this were a true regression to the means, the offspring of really tame ferrets would less tame (moving towards the mean), while at the same time the offspring of really wild ferrets would become tamer (again, moving towards the mean). In the fox experiments, ALL animals move toward the tameness end of the behavioral continuum; wild fox become tamer, but tame fox become even MORE tame. This is NOT moving towards a mean, but rather towards a single end of the continuum. Still, only breeding tame animals should signal to ANYONE of the danger of regression to the means. You have a sharp eye, and should be proud of your observation. If domestion was ONLY the skewing of a single behavioral trait, I would side with your observation. However, since specific structural changes can be documented in the migration of melanocytes, in brain structure, and in the production of specific brain chemicals, I would reject regression to the means. We are not just skewing a behavior, but rather a suite of physical, biochemical, and behavioral changes. Because the efforts have been duplicated in other lineages, by other researchers from different countries, and in other species, regression to the means is probably not taking place. Understanding exactly HOW breeding for tameness impacts so many physiological systems is another matter and another post. I apologize to any math majors if I have misinterpreted or poorly explained this effect, and if so, I hope they clarify my blunders. Bob C [Posted in FML issue 4126]