The discovery of a 2 million-year-old skull in a South African cave changes the way we think we know about one of the oldest ancestors of mankind, scientists say in a new study.
But a newly discovered fossil specimen from an extinct human race Paranthropus robustus Provides researchers with a unique snapshot of transformations Climate change Can be unleashed on populations living under environmental pressure – preferred adaptations to make life easier and more viable.
B. Robustus, Named after it Strong look A large, sturdy skull, with jaw and teeth, appeared in South Africa about 2 million years ago, eventually becoming one of the first early hominin species discovered and studied by anthropologists of the 20th century.
However, not everything seems to be B. Robustus Individuals are equally strong, and we know this thanks to the newly discovered model identified as DNH155.
DNH 155, discovered in 2018 by a student on a field trip to the Trimolan Caves in northwestern Johannesburg, looks a little different. B. Robustus Relative, at least based on the fossil evidence now found.
DNH155, one male, is significantly smaller than the others B. Robustus The specimens are thought to be male and were recovered from a nearby site called Swartcross. In fact, the minor status of DNH155 is very closely related to that of a female individual known as DNH7, even from the Trimolan quarry site.
But there is more to it than just the geography that separates these two ancient peoples. There is also the matter of time: about 200,000 years, give or take.
“Trimolan predicted the Swartcross about 200,000 years ago, so we believe it B. Robustus Emerged over time, the Trimolan represents an early population, and the Swart Crans later, a more anatomically derived population. ” Explains Jesse Martin, co-lead author and Ph.D. candidate in Paleoscience from the University of Latrope, Australia.
In them New study, Martin and his team argue that DNH155 and DNH7 offer a view of a primitive state B. Robustus Microbiological changes over the next 200 thousand years promoted the adaptations found in the Swartgrass collection.
One of the main factors that could bring about such an event, researchers consider, is an ancient chapter in climate change that affected the South African landscape 2 million years ago, in which the environment became more open, drier and cooler.
Those changes will retain their identity in many things, including available foods B. Robustus, It is necessary to bite and chew hard plants – munch and masticate to DNH155 and DNH7 will not be so easy, giving the structure of their teeth and chewing muscles.
“Compared to the geographically younger models from the site of the nearby Swartcron, the Trimolan Cranium is very clearly adapted to eating less of these challenging menu items.” Says Gary Swartz, an evolutionary anthropologist at Arizona State University.
Despite the successful adaptations that slowly changed B. RobustusIn about 200,000 years, it is unfortunate that it did not exist. The species eventually became extinct. At the same time, our direct ancestor, The man standing, Developed in the same part of the world.
“These two different species, H. Erectus With their relatively large brains and small teeth, and B. Robustus With their relatively large teeth and small brains, they represent different evolutionary experiments. ” Says Angeline Lees, co-lead author and archaeologist From the University of Lahore.
“When we were the winning generation in the end, the fossil record marks it B. Robustus More common than H. Erectus On land 2 million years ago. “
Findings have been reported Natural Ecology & Evolution.