Ancient baby jawbones shed light on the origin of the human race

AFP

La Jornada Newspaper, Thursday, June 5, 2025, p. 6

Toulouse. Fossilized jaw fragments from two-million-year-old infants found in Africa, the cradle of humanity, have helped a Franco-Italian research team shed new light on the origins of the human race.

The study, conducted by José Braga (French National Center for Scientific Research, CNRS-University of Toulouse) and Jacopo Moggi-Cecchi (University of Florence) and published in Nature Communications , shows greater diversity and complexity than expected at the beginning of the Homo genus.

The bones on which this research is based (two mandibles and a maxilla from babies exhumed a few years ago in Ethiopia and South Africa) show that from that moment in the individual's life, 2.2 million years ago, we were dealing with two distinct species that developed in completely different ways , Braga said.

Morphological differences

While the jawbone from Ethiopia's lower Omo Valley, attributed to Homo habilis , is very different from that of modern human children , the one from the South African site of Kromdraai, attributed to Homo erectus , is very close to that of modern human children , he said.

Due to the young age of the individuals to whom they belonged, it seems unlikely that the morphological differences so marked are due to the environment (lifestyle or diet), as may be the case with the skeletons of adults.

The comparison of both jaws shows us that, for millions of years, they were two completely different species that coexisted somewhere on the African continent , and that Homo erectus was closer to us than Homo habilis , he added.

“These new discoveries contribute to a more nuanced view of the origins of the genus Homo ,” when the first representatives of the human lineage diverged from the other great apes.

This suggests that the roots of humanity are both older, more diverse and more branched than previously thought , the CNRS noted.