Ancient human-like fossils in South Africa may be more than a million years older than previously thought, raising the possibility that species evolved from humans, a new study finds. A new day could rewrite a few important stages of human evolution. That is because the findings suggest that these fossils are part of a species that may have preceded the ancient 3.2 million-year-old “Lucy” fossil. Lucy’s breeds were thought to be the main competitor to the direct human ancestors. Homo sapiens is the only member of the human family, the Homo species. Previous research has suggested that the leading candidate in Homo’s predecessors may be the type of Australopithecus, which lived about 4.1 to 2.9 million years ago. Australopithecus, meaning “southern monkey,” includes Lucy’s species, Australopithecus afarensis.
When Lucy was discovered in Ethiopia in 1974, her bones were the oldest and most complete skeleton of the ancient hominin, a group of humans and extinct species that are more closely related to humans than any other animal. The largest source of Australopithecus fossils found to date is the Sterkfontein Caves in South Africa, part of a site called the Cradle of Humankind. Sterkfontein became famous when the first known adult Australopithecus was discovered there, in 1936. Over the decades, scientists have discovered hundreds of fossils of hominin in Sterkfontein, often classified as members of the genus Australopithecus africanus.
However, a previous study suggested that the Sterkfontein bones were only 2.1 to 2.6 million years old. In contrast, the oldest known Homo fossils, unearthed in Ethiopia, date back about 2.8 million years. This suggested that the Sterkfontein Australopithecus species could not be Homo’s ancestors. Instead, researchers have suggested that the ancestors of the human race were species of Australopithecus in East Africa, such as Lucy’s, A. afarensis, and A. South African africanus is from A. East African afarensis. However, there is much debate about the age of the fossils in Sterkfontein. For example, the almost complete skeleton known as Little Foot found there is estimated to be 3.67 million years old, according to a study by Darryl Granger, a geologist at Purdue University in West Lafayette, Indiana, and colleagues.
In a new study, Granger and colleagues sought new estimates of the age of some hominin bones in Sterkfontein. They found that the bones may be between 3.4 and 3.7 million years old. This makes them older than Lucy and opens up the possibility that Homo could have originated from the South African Australopithecus species, not East Africa as was thought for a long time. Understanding the days of Sterkfontein remains can be difficult. In general, scientists measure the age of fossils by analyzing the layers in which they are found; if the layer is deep, it can be old. However, a complex system of caves in Sterkfontein could lead to older deposits being mixed with smaller items, making it difficult to date.
Other dating techniques and examples of Australopithecus in Sterkfontein include examining the bones of other animals, such as horses excavated near hominin remains, or flowstone connected with fossil layers – small sheets of rock embedded in running water found throughout walls and floors. in caves. However, the bones can shift between caves during floods, and a smaller flowstone can be added to the old sediment, meaning that the dates taken from these paths may be incorrect.One way that may be more accurate is to look at real fossils where fossils were found. In a new study, researchers analyzed a concrete matrix in which bone fragments are embedded, called a breccia.
Scientists are analyzing the so-called cosmogenic nuclide within rocks. These are the most unusual versions of the elements, or isotopes, produced by cosmic rays – the supernatural particles that constantly blow up Earth from space. Each isotope of the element has a different number of neutrons than the atomic nucleus – for example, aluminum-26 has one smaller neutron inside its nucleus than normal aluminum.Aluminum-26 forms when quartz-containing rock is exposed on the surface, but not after it has been buried deep in the cave. Therefore, researchers can record sediments in the cave, as well as the remains in them, by measuring levels of aluminum-26 in conjunction with another cosmogenic nuclide, beryllium-10.
“I was initially amazed that the new 3.4 to 3.6 million years of age were very close to the old sediments,” Granger told Live Science. “The implication is that all the fossils of Australopithecus in Sterkfontein fall in a very short time, and at a time when there was a great diversity of hominins in East Africa as well. East Africa and South Africa.”This is a new find, showing A. africanus is at least as old as, if not older than A. afarensis, may give the impression that A. africanus descended on A. afarensis. And in fact, A. africanus has a monkey’s skull and facial features much older than A’s. afarensis, biologist Yohannes Haile-Selassie, director of the Institute of Human Origins of Arizona State University, who did not participate in the study. Instead, he suggested that A. africanus and A. afarensis may be a type, derived from a single adult ancestor such as A. 3.8 million-year-old anamensis, Haile-Selassie helped expose Ethiopia in 2016.
For more read: https://www.livescience.com/south-african-fossils-human-evolution
