The aim is to look for the molecular bases of what makes us humans
A study carried out by researchers from the Research programme on Biomedical Informatics (GRIB) at IMIM (Hospital del Mar Medical Research Institute) and the UPF has used new human genetic data to learn more about mutations that may have conferred a selective advantage to humans over the past 5 million years of evolution. This provides researchers with a new vision on human evolution.
The availability of the genetic variants in a large number of people, through initiatives such as the Project 1000 Genomes, is useful not only to understand the genetic basis of diseases, but also to carry out research on the human evolution. According to Mar Albà, an ICREA professor and the coordinator of the IMIM research group on Evolutionary Genomics “This variation provides us with a measure on the proportion of the amino acid changes seen typically in a protein while it maintains its function. Once we have this value, we can then count the differences with the ancestral protein in humans and chimpanzees and if we find there have been more changes than expected, this is because the function of the protein may have changed during human evolution”.
“If a mutation or a change increases the chances of survival in the person carrying it, this mutation will tend to become prevalent in the population. The new protein will have changed its function compared to the ancestral protein. These are the kind of changes that we are interested in identifying to understand how humans have adapted to the environment” says Magdalena Gayà, a former researcher in the team led by Dr. Albà, and currently a researcher at the Biotechnology and Biomedicine Institute (IBB) at the Universitat Autònoma de Barcelona (UAB). The use of sequences that code the proteins of humans, chimpanzees, macaques and mice has allowed researchers to identify around 200 genes that would have accumulated adaptive changes in humans. The list includes several genes that code neuronal proteins.
The authors of this study have proven that genetic variation data are useful to carry out research on the remote past of mankind. It will now be interesting to see if other human species, such as the Neanderthal, carried the same version of the protein as modern humans.
Article of reference:
Gayà-Vidal M & Albà MM (2014). Uncovering adaptive evolution in the human lineage. BMC Genomics 15:599. http://www.biomedcentral.com/1471-2164/15/599.