South Africa – An international team of scientist led by Professor Lee R. Berger, announced on Thursday the discovery of a new hominin species named Homo naledi from the fossils found in the Rising Star cave in South Africa. This adds a new branch to the human species family tree.
Modern humans, who belong to a species named Homo sapiens, continue to be until today the only living species in our genus. But 20,000 years ago there were other species of the genus Homo that are now referred as “hominins”.
The discovering of Lee R. Berger, an American paleoanthropologist who is a professor of human evolution studies at the University of the Witwatersrand in Johannesburg, describes an unusual collection of hominins fossils found in Africa belonging to a species called Homo naledi that could be an antecessor of the human species.
There were approximately 1550 specimens of hominin remains of most of the bones in the skeleton from at least 15 individuals, representing a small portion of the total fossil content according to eLife magazine. It constitutes one of the greatest and most complete discoveries of hominins rests found until this date.
The remains have similarities between both humans and apes. The creature, which evidently walked upright, represents a mix of traits. The hands and feet look like Homo, but the shoulders and the small brain recall Homo’s more ape-like ancestors, the researchers said.
“It’s brain was no larger than a baseball, its shoulders and torso primitive, its fingers long and curved, allowing H. naledi to climb and swing from the trees. […] Its long legs and feet, nearly indistinguishable from those of modern man, allowed it not only to walk upright but also to travel for many miles at a time” reported from The Washington Post Amy Ellis Nutt.
Scientists also believe that Homo naledi buried their dead. The number of bodies, their location, and the hard access characteristic of the cave makes scientists believe that Naledi species left deliberately bodies in caves as a way of burying them. This has been considered as a behavior limited to modern humans and never seen before in such a primitive human, reported The New York Times. This could have big implications for understanding the origins of modern human behavior.
They may have used tools. The hands suggest tool-using capabilities as they had extremely curved fingers. More curved that almost any other species at such early state of hominin, suggesting they had climbing capabilities.
The species may have 2.5 million to 2.8 million years old. Lee Berger, who led the work, said naledi’s anatomy suggest it arose at or near the root of the Homo group, which would make the species some 2.5 million to 2.8 million years old, however, discovered bones themselves may be younger.
But until the fossils age is certain, there is no way of making an appropriate judgement of the evolutionary significance of the discovery. If the bones are about as old as the Homo, it would make the Naledi prove of the evolution going on at that time. If the fossils were to be significantly younger it would mean the species managed to retain the primitive body characteristics much longer that any known creature, experts say.
The 1400 bones, 140 teeth, belonging to at least 15 individual skeletons found, may not be that closely related with the human species, but the evidence suggest that even so, they might have presented cognitive abilities equally essential to our species and can have the possibility to rewrite Homo sapiens history.
Source: eLife
A fantastic discovery & excavation, but prof.Berger’s interpretations (deliberate burial, direct human ancestry, distance running, tool-making) are anthropocentric: comparisons with non-human animals show that Homo or Australopithecus naledi is no mystery (in fact predicted, e.g. Trends Ecol.Evol. 17:212-7, 2002, google: aquarboreal): it was was a bonobo-like forest-swamp or wetland wader who fed on aquatic herbaceous vegetation (AHV) such as papyrus sedges, waterlilies etc. (google: bonobo wading):
– The curved hand-bones suggest vertical climbing in the branches above the swamps.
– The long thumbs were less for tool use than for collecting floating AHV & for surface-swimming.
– The broad pelvises (iliac flaring & long femoral necks) were for sideward movements of the legs (femoral abduction): for climbing or swimming, not for running.
– The flat humanlike feet are more flamingo- (plantigrade wader) than ostrich-like (digitigrade runner), IOW, more for wading than for walking.
– The small front teeth & large cheekteeth can be expected with a wetland diet of AHV & possibly hard-shelled invertebrates (HSI).
– They fossilised in stagnant water (mud-stone).
Lowland gorillas often wade on 2 legs in forest swamps for sedges, frogbit etc. (google: gorilla bai), but naledi apparently exploited this special niche habitually: no wonder there were no or few other macro-fauna near the naledi fossils. It was no deliberate burial (they had ape-sized brains), but a natural process: when they died, their bodies sank into the mud; later, the underground eroded away and became a cave system. How exactly the mudstone ended up in the cave is unclear so far, but the remarkably complete skeletons leave no doubt that when they died they got almost immediately covered by mud.
When living hominids (e.g. humans & bonobos) go back in time towards the Homo/Pan last common ancestor, human ancestors show more bonobo-like features (e.g. shorter legs, smaller hip joints, smaller brain, no external nose), and bonobo ancestors show more human-like features (e.g. shorter hands & arms, longer thumbs, no iliac lengthening, flatter feet, smaller front teeth, thicker enamel), IOW, naledi, in spite of some primitive-hominid Homo-like features in hands, feet & dentition, was very bonobo-like in nearly all the rest of its anatomy, and more likely a close relative of bonobos or common chimps than of humans (google: researchGate marc verhaegen).
Its a very good species that the scientists have found.Its an amazing human ancestor.I have seen many but Homo Naledi was a very interesting one.Its Specifications are great.
Really interesting find,with obviously a lot of work completed.Problem is no dating evidence released,which opens room for scepticism.This relates to a rather overexcited approach to an unsolved or incomplete thesis.Most ancient burials, or rather at least a great many are marked by the relevance of trinkets or adornments.Had these peoples gone to the length or trouble of burying their dead then surely something of significance should have been in the offering regarding the above.The total absence of any form of manufactured tool or implement certainly leaves many unfulfilled gaps in the ideology presumed.Many of the Ape species have demonstrated some form of mourning of the dead,especially with young deaths.Eugene Marais gives quite a compelling description of the habits of modern primates.