Interesting piece of work reported in today's New Scientist. Especially given creationist ideas about what happens to the amount of information in mutations.

Firstly, a particular gene, some time between the splitting of chimps and australopithecus, and the further split between AP and modern types of hominim, a particular gene associated with brain development was duplicated. Subsequently, and at the same time as that second split, the copy duplicated itself, so that there are three copies of this gene in us. Initially this was not spotted, because they were effectively the same.

The copying process included deterioration of the genes, so that brains without the original version (work done on mice - I thought of "Flowers for Algernon") do not develop properly, but where all three are present, the brain develops over a longer period, with more complex connections, with cells which look like human brain cells. Moreover, the infants' skulls do not close the sutures until later, allowing the head to pass more easily through the birth canal, and the brain to develop more after birth, characteristics of moodern humans, and seen in the earliest homo skull.

There are a lot of links for this on Google today. Try genes, duplication, human brain, and, of course, evolution.

Penny