A team of researchers from various Spanish centers, led by the Centro Mixto Universidad Complutense de Madrid and the Carlos III Health Institute for Human Evolution and Behavior (Spain) has examined the fossils of the Sima de los Huesos at the Sierra de Atapuerca, adding a new model in the evolution of the human body, thus establishing four phases or evolutionary stages .
Scientists have analyzed in detail the fossils – which are many – of the postcranial skeleton (from the neck down), dated at about 430,000 years and recovered during the last 20 years in this well-known site. The results have made it possible to establish four large successive patterns in our evolution.
The four stages in the evolution of the human body would be as follows: first, the ardipithecs (arboreal and occasionally bipedal); then the australopithecines (bipedal but with undeniable arboreal capacities); later, that of the “archaic” human (like Homo erectus, broad, robust and with exclusively terrestrial locomotion); and finally, the modern human (tall, narrow and with a graceful skeleton).
” A global investigation of the skeleton (body shape, weight, height, body size dimorphism) and a detailed analysis of each anatomical part have been carried out in order to establish the evolution of the body shape in the genus Homo that is now proposed” , explains Carlos Lorenzo, co-author of the study.
According to the study, which has been published in the journal Proceedings of the National Academy of Sciences (PNAS) , the humans of the Sima de los Huesos were relatively tall (1.63 meters) and with a muscular and broad body (with an average weight 69-70 kgs) but with less brain mass than Neanderthals.
