I found this article while I was browsing sciencedaily.com. It is about a study that was done by a group of researchers from the University of Colorado School of Medicine, Baylor College of Medicine and the National Institutes of Mental Health. They wanted to understand how the human brain increased in size and complexity so much in such a short period of time. They found that the protein domain DUF1220 may be responsible for the increase in brain size. Humans have 270 copies of this domain and the largest brain relative to body size of any species. In other species, the number of these domains directly correlates to brain size. There was also evidence of this in humans. People who had microcephaly (brains that are too small) had lower numbers of DUF1220 and people who had macrocephaly (brains that are too small) had higher numbers of DUF1220. I thought this article was really interesting and the possibilities for using this to diagnose diseases related to the brain are exciting!