I see the differences between this post and the psychological unity of mankind one is akin to two ships passing in the night - not talking about the same thing. In general the arguments do not contradict each other.

I would like to make a few additions:

1) We cannot compare the speed of change in dogs (or pigeons) with that in wild populations. Mongrel and feral dogs are under selection in their normal environment and without control of their breeding therefore they resemble one another much, much more than do pure bred animals. The tame foxes if freed would return fairly quickly to being foxy. Humans on the other hand have continuously changed the environment in which they live (for say 50,000 years). Therefore the selective pressure is not static. So it is not surprising that new genes can arise and flow through populations. Dogs are not relevant here.

2) Genetics is more complex than algebra. In many cases there is an advantage to having two different alleles and both alleles in double dose are disadvantageous. Genes are duplicated (as a mutation) and then one allele can be conserved while another evolves under selective pressure. There are genes that control the use of groups of other genes and mutations in these can effect hundreds of genes. Epigenetic changes to genes can give very complex effects. Environmental control of genetic expression is important. Genetics is probably like an iceberg that we have not glimpsed the complexity of yet.

3) Eliezer was talking about the deep structure of our anatomy and physiology while the 10,000 year explosion book is about fairly surface differences. For example, skin colour is under the control of a small number of genes and responds relatively quickly to differences in environments sunlight (say 20-50,000 years to lighten or darken to ideal when a population moves). But human skin differs in more fundamental ways from that of other animals -amount of hair, sweat glands, amount of fat etc. Human skin is universal while its colour tracks the environment.

So in general there is nothing terribly wrong with either Eliezer's post or the present one - except nit picking complaints (The dog thing is maybe me nitpicking). They are not opposed unless you have a hangup about whether genetics is important or not.