Homo Naledi and Our Distant Ancestors Roamed The Earth Together
When bones of a new human species were found deep in a South Africa cave a few years ago, they looked 2 million years old.
But scientists recently made a startling discovery — the bones were much younger, between 226,000 and 335,000 years old. That means the newly found species, dubbed Homo naledi, roamed the landscape at the same time as ancient humans.
After the groundbreaking discovery of the 5-foot-tall hominin with hands and feet similar to our own but a brain only one-third the size, explorers searched for more bones. Their search paid off. The new fossils come from at least two adults and a child, including one that is so remarkably complete it was dubbed “Neo.”
The discovery was announced Tuesday with the publication of a series of papers in the journal eLife.
“This is incredible. What we’re looking at with Neo is a skeleton as complete as Lucy, the most famous in the fossil record,” said University of Wisconsin-Madison anthropologist John Hawks, referring to the Australopithecus afarensis skeleton found in Ethiopia in 1974.
Hawks, an expert on early hominins, is the leader of the research team at the Rising Star cave system in South Africa and the lead author of the paper describing the new fossils. Neo’s skeleton has a complete collarbone and almost a complete femur, giving researchers important clues about its size and stature as well as its ability to walk and climb.
The shape of the vertebrae has been seen before only in Neanderthals. As Neo’s skull was reconstructed bit by bit like a jigsaw puzzle, the adult male’s jaw, teeth and eye sockets became visible.
“Like all fossils that are fragmented and broken, fitting them together and seeing the face for the first time and realizing you’re looking into a face that no one has seen since (Homo) naledi’s group was there, it’s so significant,” Hawks said in a phone interview from Madison.
In 2015, an international team that included Hawks and other UW researchers revealed the largest trove of fossilized bones and teeth found in Africa. The skeletons of the previously unknown human species had been found squirreled away in caves that were so difficult to reach, organizers sought skinny paleontologists, thin and nimble enough to squeeze into the chambers to perform the painstaking work.
The initial discovery of 1,550 specimens has risen to around 1,800 representing at least 18 individuals. Scientists didn’t know the age of the bones but through a variety of techniques they were surprised to learn Homo naledi traversed Earth relatively recently.
“We expected this should be in Chapter 4 (of hominin evolution) and we found them in Chapter 9. That is a real surprise,” Hawks said. “If you talk to experts in the field, they say this is the wrong time. They shouldn’t be there then.”
If modern man, Homo sapiens, dates back to roughly the last 200,000 years and Homo erectus, an extinct hominid that walked upright and had ape-like features, dates from between 1.9 million years and 140,000 years ago, Homo naledi fits somewhere within that timeline.
Whether Homo naledi mated with Homo erectus or Neanderthals and co-mingled genes and DNA is not yet known. So far scientists have not been able to extract DNA from Homo naledi bones.
“Based on its anatomy it looked like something 2 million years old. I conclude that it probably is something that branched from our lineage. It survived for most of those 2 million years alongside with humans much more like us,” Hawks said. “You may ask ‘why did we not see this before?’ I think the answer is we haven’t looked.”
The bones were dated by measuring the amount of uranium and thorium in calcite stone deposits found on top of the fossils, which were estimated at 226,000 years. Bits of Homo naledi teeth were also ground up to measure the electromagnetic fields since teeth are imprinted with a time signature from exposure to natural radiation.
As more bones are discovered in out-of-the-way locations in the cave system, it appears that Homo naledi used remote, dark places to cache their dead, a behavior that suggests the possibility of intelligence. There were no cut marks or signs of trauma on the bones that would suggest them falling into the cave. Though there’s been no evidence found of fire or torches Homo naledi might have used to find their way through the pitch dark passages in a cave system that stretches two kilometers, scientists ponder the reason why they went to such effort to store the bodies.
“I personally think we’re looking at evidence Homo naledi cared very deeply for members of their group and wanted to put these bodies where they would be protected,” Hawks said.
Hawks is returning to South Africa this month to spend the summer working at the Rising Star cave excavation. As teams of small anthropologists shimmy and crawl through tiny crevices into chambers looking for more fossils, Hawks will work outside.
“I don’t fit,” Hawks said. “It’s like working in space in the sense that I can’t go there and the only means I can have of understanding is with the science we’re using.”
new data does not alter the theory
it only impacts parts of the hypothesis
and re-orders what is known
science is that robust, it is completed in with new details
one planet, it is one planet. no place is more specialGeorge Meladze
Races differ profoundly. Asians are considerably different from Caucasian and Africans. It is only logical to suppose that Caucasians have also evolved in some specific geographic area, other than Asia and Africa, most likely Europe.Kathryn-Lesley
Very interesting, I’d like to stay posted if possible.
+George Meladze “race” is not a science word, it is a social prejudicial word.
The oldest homonyms?
The 21st Century Piltdown Man Hoax
Don’t even want to touch this one. Still reeling from the recent theory about blonde hair, blue eye Egyptians…
+Jay Vollmer Hominids?
🎵…antonims, synonims adjectives, verbs! 🎶
+Night Garden Why, think Egyptians were negroid? It is absurd.
+Nina Tryggvason Like gender? There morphological types of humans, called races. Asian differ morphologically from Africans, for example.
+George Meladze I don’t but many do. Just looking at their portrait sculpture tells me most were anything but “African” in appearance, by today’s standards. Fascinating… (I was being slightly sarcastic, btw.)
+Night Garden Surely, like Nefertiti, for example. Not immediately, but later I understood it was sarcasm.
+George Meladze “Race” is a pejorative term and has zero scientific meaning, and your childish geographic terminology has no genetic value.
+Nina Tryggvason You are welcome to disagree here, you are not welcome to dictate, nor be disrespectful.
+Joe Carter if they can be racist and I am the one being told I am rude, can you see the problem yet?
Well this is sure not to cause a stir… </SARCASM>
given that I am the only one you are responding to, you are on a side. given that I am the only one who’s posts you are moderating, you are on a side.
Sleep Disorders Affect Men and Women Differently
Results show that women are more likely to feel tired and depressed than men.
The research is in Journal of Clinical Sleep Medicine. (full access paywall)
because our problem solving mechanism is different and dreams are where we work things outErick Bremont
We too are working _ do not worry youNina Tryggvason
+Erick Bremont goods example of the problem and solutions differing, sexism much?
The last common ancestor we shared with chimps seems to have lived in the eastern Mediterranean – not in East Africa as generally assumed. This bold conclusion comes from a study of Greek and Bulgarian fossils, suggesting that the most mysterious of all ancient European apes was actually a human ancestor, or hominin. However, other researchers remain unconvinced by the claim.