Evolução humana e de outros primatas: o que os dados genéticos nos contam a respeito
Dr. Bortolini’s talk revealed fascinating new possibilities of studying human evolution using genetic data. Comparing available genome sequences from different primate species, her group is investigating characteristics that can make humans unique. Of particular interest are the genes that code for the oxytocin hormone (OXT) and its receptor (OXTR). They observed clear signs of positive selection in amino acid variants, both in OXT and OXTR among the primates studied, suggesting a process of co-evolution. Oxytocin is related to bonding and parental care and a functional alteration in its sequence, leading to enhanced activity might have propitiated a selective advantage.
In her talk, Dr. Bortolini showed as well some interesting examples of how human culture can push forward rapid evolutionary changes in our species. Two investigations led by her group showed modifications in the genes related to cholesterol metabolism and the advent of maize agriculture in Mesoamerican cultures. In Brazil a striking example is the morphological cranial shaping in the Xavante Amerindian tribes possibly due to sexual selection.
As usual the “Seminários da Biologia” gave us food for thought and reflection. I strongly invite you to come for the next sessions.