In “Mutations in Single Gene May Have Shaped Human Cerebral Cortex” (ScienceDaily, Apr. 28, 2011), we encounter a surprising claim:
The size and shape of the human cerebral cortex, an evolutionary marvel responsible for everything from Shakespeare’s poetry to the atomic bomb, are largely influenced by mutations in a single gene, according to a team of researchers led by the Yale School of Medicine and three other universities.
The findings, reported April 28 in the American Journal of Human Genetics, are based on a genetic analysis of in one Turkish family and two Pakistani families with offspring born with the most severe form of microcephaly. The children have brains just 10 percent of normal size. They also lacked the normal cortical architecture that is a hallmark of the human brain. This combination of factors has not been seen in other genes associated with the development of the human brain, the authors note.
The researchers found that mutations in the same gene, centrosomal NDE1, which is involved in cell division, were responsible for the deformity.
From which they extrapolate,
“These findings demonstrate how single molecules have influenced the expansion of the human cerebral cortex in the last five million years,” Gunel said. “We are now a little closer to understanding just how this miracle happens.”
Bump. All they’ve really discovered is that NDE1 is a necessary component of healthy brain development. Along with hundreds of others whose malfunction could cause deficits, minor or severe. The rest is pure extrapolation.
With all this hype blowing around, if they ever do find anything really significant, how will we know?