Scientists explain the cranial differences between hominids

Scientists explain the cranial differences between hominids

Florida State University anthropologist Dean Falk and his team, consisting of Marcia S. Ponce de León, Cristoph P.E. Zollikofer and Naoki Morimoto of the Museum and Anthropological Institute of the University of Zurich, has carried out research that explains why human skulls are wider and they allow a brain capacity greater than that of other primates.

Falk's team used one of the most important fossils ever discovered: taung fossil, which is estimated to have 2.5 million years old and was found in 1924 in Taung (South Africa).

The first characteristic that researchers have discovered is a “persistent metopic suture", that is to say, an unopened opening in the frontal bone of the skull, which allows a baby's head to be flexible during labor to facilitate delivery. In the great primates (gorillas, orangutans and chimpanzees) the metopic suture is closed shortly after birth. In humans, on the other hand, it does not close until two years later, in order to accommodate the rapid growth of the brain.

The second feature is the fossil endocranial map, which allows researchers to examine the shape and structure of the brain. After examining the taung fossil and a large number of skulls belonging to other hominids, as well as several scans of the bones and fossil records from the last 3 million years, Falk and his team have highlighted three important aspects: Persistent metopic suture is an adaptation to deliver babies with larger brains; It is related to the change to a larger brain after birth; and may be linked to expansion in the frontal lobes.

Falk comments that the persistent metopic suture, probably occurred in conjunction with the refinement of the ability to walk without using the arms. In addition, the ability to walk upright caused an obstetric dilemma: labor was complicated by contracting the hips, while brain size increased. The persistent metopic suture contributed to an evolutionary solution to this dilemma, to which we must add the expansion of the frontal lobe as a cause of its late fusion.

The researcher does not hesitate rate these findings as "significant", Since, for him, they provide"a plausible explanation for why the hominin brain may have grown larger and more complex”.

Source: Florida State University

Passionate about History, he has a degree in Journalism and Audiovisual Communication. Since he was little he loved history and ended up exploring the 18th, 19th and 20th centuries above all.


Video: Skullcast: comparison of hominin skulls