Thanks Lowpro ... interesting article. But it still doesn't explain exactly how it happened. In fact the article confirms my initial point that this issue remains a scientific mystery and does not conform to standard theories of evolution. Until we get further information, one could just as easily theorize that the presence of 270 copies of DUF1220 encoded into the human genome, ( far more than other species ) suggests some sort of genetic engineering rather than it does evolution.
Honestly you could have done that without the article, it would have just been without knowing what DUF1220 is.
But let me try walking you through how evolution works on a molecular level. The domain DUF1220 on average has about 270 copies in the human genome. Some humans probably have more, others less. And then there's the problem of how actively those domains are transcribed but that's not the issue in reproduction, how genes continue through organisms and generations.
Using the theory of evolution I could hypothesize that the domain underwent a series of replication within the genome (
like this) of human ancestors probably before the split in the populations between what evolved into chimpanzees and
Homo ancestors. I say before because we see a LOT of skull variation within ancestor fossils of homonids, so I think that's a safe assumption seeing as skull size is linked to brain size.
So really ToE answers why there are a prevalence of the protein domain in humans due to replication and continuum along Homonid lineages (skull size supports the hypothesis)
I don't need a designer for this so theorizing such needs more evidence against the null hypothesis that evolution provides. Until you can provide statistical significance against it, such a theory of design is untenable.
*An addendum. While it's nice to have one protein link to the evolution of intelligence I highly doubt that it takes just the one type of protein. Transcription and translation works in feedback patterns (I say patterns because while there's a biochemical feedback this feedback also operates in a continuum along the lineage; we call this natural selection) so just assuming that it's replication alone a some constant rate wouldn't be accurate. You need to identify the biochemistry relating to the rate of translation. An example is
this paper there are many similar studies however this one's free. It's imperative to consider the rate and change according to the lineage of the organism so do not assume a constant rate for proteins, especially proteins that obviously had a major shift in expression such as DUF1220.
For all your reasoning of a designer I just cannot see the necessity. Biochemistry doesn't need a designer any more than ice needs one to melt when heat can give you expected results.
EDIT: HAHAHA I was right!
http://www.ncbi.nlm.nih.gov/pubmed/16946073 I'm awesome. I expect my Ph.D any day now