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Tag: Neanderthals

New Species of Human Ancestor Discovered in Africa is “Rosetta Stone” of Genus Homo

Archaeologists in South Africa have discovered a previously unknown species of human ancestor in the form of the 1.9 million-year-old partial skeletons of an adult female and a young male hidden deep in an underground cave outside Johannesburg.

Theyre thought to represent a key period of evolutionary transition between ape and man. The find is believed to be so important that the lead scientist behind their research has described the species dubbed Australopithecus sediba as potentially being the Rosetta Stone that unlocks our understanding of the genus Homo.

The find comes hot on the heels of the discovery of the remains of a 40,000-year-old human finger in Siberia, thought to belong to another previously unknown ancestor of Homo sapiens. The find suggests an undocumented species of man that lived alongside Neanderthals and early modern humans in parts of Asia as recently as 30,000 years ago.

Its represents the first new human ancestor identified since the discovery of Homo floresiensis, the strange hobbits who are thought to have inhabited the Indonesian island of Flores until 13,000 years ago.

Climbing Down From the Evolutionary Tree

Lee Berger, a palaeontologist at the University of Witwatersrand in Johannesburg, is the expert currently working hard to explain the story of Australopithecus sediba, which is represented by a pair of unlucky souls possibly mother and son who met their fate by falling together through a fissure in ground, before being carried a few metres by mud or water into a subterranean pool where they were gradually encased in rock.

Theyre believed to originate from the very foot of the human family tree, and are therefore thought to be of enormous importance to the study of mans evolution from primates.

These fossils give us an extraordinarily detailed look into a new chapter of human evolution, Berger told The Guardian, and provide a window into a critical period when hominids made the committed change from dependency on life in the trees to life on the ground. Sediba may very well be the Rosetta stone that unlocks our understanding of the genus Homo.

Some experts have voiced skepticism about the importance of Australopithecus sediba, however, because it shares such prominent anatomical features with both early humans from the genus Homo (long legs and a pelvis well adapted to walking upright), and their ancient predecessors the Australopithecines or southern apes (long arms like orang-utans).

The transition to Homo continues to be almost totally confusing, Donald Johanson of Arizona State University in Tempe an opponent of Bergers theory told Science magazine. Its Homo, he concluded.

The debate promises to continue.

DNA Evidence Points Finger in Direction of New Human Species

There was nothing so immediately dramatic about the remains found in Siberia specifically Denisova cave in the Altai mountains, a range that straddles Russia, Mongolia, China and Kazakhstan. The finger, which may have belonged to a young child and was recovered from a layer of rock in the cave dated to between 48,000 and 30,000 years ago is tiny, and offers no visible hint of unusual origins.

It was genetic testing that yielded results that left its researchers from the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany stunned. There was no match with the DNA profile of either Neanderthals or early modern humans. It is the first time a new type of human has been identified purely from DNA analysis.

It really looked like something I had never seen before. It was a sequence which is similar in some ways to humans, but still quite distinct.

It really looked like something I had never seen before, the Max Planck Institutes Johannes Krause told The Guardian. It was a sequence which is similar in some ways to humans, but still quite distinct.

Project leader Svante Pbo could hardly believe it when Krause called him to reveal the results of the test. It was absolutely amazing, I didnt believe him, Pbo said. I thought he was pulling my leg.

Krause and co are now concentrating on DNA from the nuclei of cells in the finger in a bid to figure out where the species fits into the human family tree, and also if it interbred at all with Neanderthals and modern humans.

Research On Sex Lives of Ancestors Hints At Why Monogamous Humans Out-Competed Neanderthals

A research team from the University of Liverpool, led by Evolutionary Anthropology PhD student Emma Nelson, reckon theyve made some tenuous inroads into establishing just how much early human-like primates liked to play the field when it came to sex. With it, they may have found some clues as to why Homo sapiens managed to see off Neanderthals as the dominant species on the planet.

The secret is in the ratio between the index and ring fingers on human hands, which are thought to be telltale indicators of how much androgen and with it, testosterone a person is exposed to in the womb. More androgen means longer ring fingers and a lower index-to-ring finger ratio, and vice-versa; studies (highly contentious ones) have suggested that men and in some cases women exposed to a larger amount of androgen will probably be physically and sexually more competitive, whereas those with shorter ring fingers are more likely to be monogamous.

Nelson and co hunted down male primate fossils that contained hands with intact index and ring fingers two Neanderthals and one Australopithecus afarensis (an extinct hominid ancestor of modern humans) and got their measuring tapes out. The Neanderthal had longer ring digits, suggesting he was a promiscuous chap who spent more time chasing skirt than feathering the nest; the Australopithecus afarensis had shorter ring fingers, suggesting he was a faithful chap who cared for his mate.

They were, in technical terms, a non-pair bonded and pair-bonded male respectively. What theyre seeing is very interesting, commented Dean Snow of Pennsylvania State University, speaking to Discovery News, on Nelson and her teams findings. The difference between being pair-bonded and non pair-bonded mating is a major watershed within primates. If a distinction is that Neanderthals werent pair-bonded and modern humans were, that would be a major consideration in trying to figure out why modern humans out-competed Neanderthals in Europe.

The Neanderthal had longer digits, suggesting he was a promiscuous chap who spent more time chasing skirt than feathering the nest.

The difference would have been most crucial, Snow pointed out, when it came to pregnancy. A pair-bonded male would stick around to help his partner out with food and protection while she was in such a vulnerable condition, greatly improving her and her childs chances of survival. This monogamy would be beneficial to the future of the species too.

Its of course a massive leap from a set of stubby digits to solving one of the great conundrums of human evolution, and Nelson acknowledges that there is much more work to be done. Many more fossil hominids in particular skeletons of Homo sapiens that lived at the same time as Neanderthals need looked at. But it seems there is much to be learned from the sex lives of our ancestors, and as much to be learned from the backs of our own hands.

Picture by Dan Shouse. Some rights reserved.