A groundbreaking study published recently delved into 430,000-year-old fossils found in northern Spain, shedding light on the evolution of the human body's size and shape. The research, led by anthropologist Rolf Quam from Binghamton University, involved an international team studying the human fossil collection from Sima de los Huesos, a site with the world's largest collection of human fossils from that era.
The researchers discovered that the ancient Atapuerca individuals were relatively tall and robust, with wide, muscular bodies and less brain mass compared to Neanderthals. Interestingly, the Atapuerca humans exhibited anatomical features shared with Neanderthals but not present in modern humans, indicating a close evolutionary relationship to Neanderthals.
By comparing the Atapuerca fossils with other human fossils, the researchers identified four main stages in the evolution of the human body, based on arboreality (living in trees) and bipedalism (walking on two legs). The Atapuerca fossils represented the third stage, with tall, robust bodies and a terrestrial bipedal lifestyle, excluding arboreal behaviors. This body form likely persisted throughout the genus Homo for over a million years, from earlier members like Homo erectus to later ones like the Neanderthals.
Interestingly, it was only with the appearance of our own species, Homo sapiens, that a new body form emerged—taller, lighter, and narrower. Hence, the Atapuerca humans provide a unique glimpse into the general human body shape and size during the million years leading up to the advent of modern humans.
The findings, documented in the paper titled “Postcranial morphology of the middle Pleistocene humans from Sima de los Huesos, Spain,” were published in the Proceedings of the National Academy of Sciences. This research highlights how the human body's evolution remained relatively stable for much of our evolutionary history until the emergence of Homo sapiens brought about significant changes.
Source: Binghamton University