I'm still not convinced. If it's 90% heritable, then the average of the shortest population needs only be 5' tall. That's pretty short. Nutrition could accoun

I'm still not convinced. If it's 90% heritable, then the average of the shortest population needs only be 5' tall. That's pretty short. Nutrition could account for the rest. Yes, nutrition is environmental, but it doesn't change my original claim. Our physical ability to respond to environmental changes is inherited. If you feed someone who has inherited the genes from two 5' tall parents, I highly doubt you could feed one twin better than the other and get a 6" difference in height. You know by thinking about it that it won't happen. Furthermore, 4 generations of offspring will lead to genetic differences in the population. Foxes can be domesticated in 10 generations. That's a huge divergence in phenotype.