Independent Evolution of Brain Parts Possible

In a collaborative work between The University of Manchester and the USA, biologists feel they have good reasons to believe that parts of the brain can evolve independently. It lays a framework which hopefully will trigger more significant discovery about our brain.

Collaboration between Harvard Medical School and the University of Tennessee which spans 15 years are able to identify multiple genetic loci, which are believed to have direct influences on the development of various parts of the brain. The objective is to ascertain if different brain parts are capable of responding to evolutionary stimulus (a.k.a. mosaic evolution) individually or if the development happens in whole (as illustrated in concerted evolution). This study stands out as it focuses on just single species and it has been included in the journal Nature Communications for publication.

Scanning was done on 10,000 mice brains, with 7 individual brain parts measured by their respective weight and volume. Barring the Y chromosome, the entire genome and gene set are then analyzed.

Spokesman at the Faculty of Life Sciences, Dr Reinmar Hager, draws a link between individual brain parts size to the genetic make up.  The study points to the likelihood that certain gene sets seem to have direct influence on the size of individual brain parts, rather than the collective gene sets. The efforts to link size of individual brain parts versus the overall size of the brain do not yield positive conclusion.

Image [Click to enlarge]

Dr Hager ventured that if evolution of the brain really happens in whole, naturally same set of genes would be expected to exert their influences simultaneously, controlling sizes of all individual parts. Instead the finding supports mosaic evolution. There seems also no direct link between the size of the brain parts and the overall size of the brain, which is also consistent with mosaic evolutionary.

The experimental data has allowed the research team to perform meaningful genetic analysis pertaining to the size of brain specifically and the body generally. In their attempt to co-relate genes that help to regulate brain size and body size, they concluded that different gene sets function separately to regulate growth of brain and body respectively.

So it seems clear that our brain and body evolve in their own individual pace, with no relationship whatsoever between them. With the conclusion of this research, Dr Hager's next mission is to pin those genes down that are specifically responsible for the growth of individual brain parts.

The implication is huge! With the successful identification of these genes, it will definitely ease future work on neuronal disease and brain development. Our brain will be in good hands!