Daniel Turbón
PHOTO: Manuel Castells

"The increase in brain size and brain restructuring, i.e., greater neurological complexity and a sudden acceleration of the brain development two million years ago, have been decisive factors in the evolution of man". For Daniel Turbón, physical anthropologist and Full Professor of the University of Barcelona, this acceleration was due to genetic changes:"the finding of some genes involved in the training of the brain and that have to do with language and the ability to make decisions, which were duplicated in man and not in primates".

According to the expert, who was invited by the School de Ciencias, at partnership with the CRYF (group of research Science, Reason and Faith), to give a seminar for teachers, it can be said that the first humans appeared approximately two million years ago, with the genus Homo and its name habilis. "These arose from bipedal ancestors of 4 million years ago. They stand out for their Degree of encephalization (ratio between the weight of the brain and the body), and for the reduction of the fetal head at the moment of birth. With the data currently available, the encephalization coefficient of Homo habilis is 63.8; that is, 64% of the coefficient of present-day man," he stressed.

This and other discoveries made possible by research genomics and by the development of bioinformatics," he added, "have made it possible to clarify the different phases of the evolutionary process by paying more attention to Degrees of evolution, and less to differentiation by species".

Women and the group: keys to survival
Turbón also referred to the role of Homo females in the evolutionary process. In his opinion, "no character, no matter how advantageous (brain), can be explained without reproductive efficiency. Women sacrificed somatic growth (20% compared to men) in order to channel resources into the reproductive effort". The human group also became involved in the care and viability of their offspring, consolidating the demographic increase. For the professor, "it is paradoxical that Homo habilis was formed at a time of climate change, in the middle of African savannahs, an environment of enormous danger from predators, which forces us to accept that human groups must have been very cohesive behaviorally and involved in the viability of their offspring, who were increasingly defenseless due to a process of lengthening of growth periods and development (hypermorphosis)".

However, in the opinion of Full Professor, it should not be forgotten that, "although morphological changes have been determinant in human evolution, what is truly peculiar to man is the development of culture, cognition, making and use of tools, communication through spoken language, spiritual and artistic life, and the ability to transmit all this from generation to generation".