Apr 15, 2021 10:57 PM
Our oldest ancestors who looked human like may go way back ... like 2 million years back
https://www.syfy.com/syfywire/homo-erect...look-human
EXCERPTS: Homo erectus is the oldest ancestor we have with more human than apelike characteristics. It was not the first hominid to stand up, but it started showing significant brain growth and evidence of tool use that set it apart from Australopithecus and earlier Homo species. But just how old is H. erectus?
The answer could be around 2 million. At least that was what paleoanthropologist Ashley Hammond, who recently published a study in Nature Communications, and her team found when they reexamined a prehistoric bone fragment. “We were unsure exactly where the fossil came from,” Hammond tells SYFY WIRE. “We were quite surprised by where a previous study showed its location because it was not where we were expecting it to be.”
[...] After extensive testing ... Hammond concluded that it must have come from these older deposits, meaning it really is 2 million years old. That wasn’t the only thing that surprised them. Foot and pelvis fossils that might have been from the same H. erectus individual also appeared.
“It is likely that they are the same individual since they were found so close together, but we cannot prove this,” Hammond says. “If researchers are able to find additional footbones or pelvic material from early Homo erectus, this would allow critical comparisons of the anatomy that might strengthen our claim.”
If these bones really are from the same individual or even another individual of the same species that is as old as the rocks [...] it could mean that the oldest postcranial (anything below the head) fossils from H. erectus have been found. These fossils are even older than the 1.7-million-year-old H. erectus bones found in Dmanisi, Georgia. However, it is unlikely that this can be proven anytime soon. DNA degrades fast, and any genetic material that might have been in the fossils has long since disintegrated.
Even if they were not from Homo erectus, what could be inferred from the fossils was that they had a more human than apelike morphology, and were almost definitely from some Homo species... (MORE - details)
Denisovan DNA may have aided Pacific migration
https://cosmosmagazine.com/history/palae...migration/
EXCERPTS: . . . By examining the genomes of 317 present-day individuals from 20 populations, the team found that the ancestors of modern-day Pacific populations interbred with little-understood ancient hominins called Denisovans. This genetic mixture seems to have bolstered the immune system and helped these early explorers adapt to living on isolated islands. The results may have implications for the health of Pacific populations today. Thepaper is published in Nature
[...] The populating of the Pacific is one of the most impressive feats of exploration in human history. [...] This enormous region is divided into Near Oceania (including Papua New Guinea, the Bismarck Archipelago and the Solomon Islands) and Remote Oceania (Micronesia, Santa Cruz, Vanuatu, New Caledonia, Fiji and Polynesia).
Our current understanding is that after humans migrated out of Africa, they flowed down through South East Asia, hopping across narrow straights and between islands. From Timor, they used rudimentary rafts or dugout canoes to cross to Papua New Guinea, then headed down the scythed curve of the Bismarck Archipelago, and reached the far edge of the Solomon Islands by around 40,000 years ago. There, nothing but the open ocean lay ahead of them, and so these people – the Near Oceanians – stopped, and Remote Oceania remained uninhabited.
Then some 5,000 years ago, a group of humans from what is now Taiwan left their home shores and journeyed south through the Philippines and Indonesia into Near Oceania. Called Austronesians, they brought with them sophisticated maritime technology and seafaring skills. They mixed with populations of the Near Oceanians, forging a new people – the Lapita – who then struck out to populate the rest of the Pacific.
[...] Previous work has shown that Neanderthal DNA has improved the adaptive capacity of modern humans, with beneficial mutations including those related to skin pigmentation, metabolism, and neural development. This new study now shows that admixture with Denisovans bolstered the immune system of Pacific populations, which may have helped humans adapt to and survive local pathogens when they spread into isolated island environments.
Plus, the mixing between humans and Denisovans didn’t occur just once – at least four independent mixing events occurred with at least two different lineages of Denisovans, as recently as 21,000 years ago. Two of these mixing events occurred after the emergence of the Lapita culture. “Collectively, our analyses show that interbreeding between modern humans and highly structured groups of archaic hominins was a common phenomenon in the Asia-Pacific region,” the authors write in their paper.
[...] this also improves our understanding of the elusive Denisovans, a species for which we have very little fossil evidence... (MORE - details)
https://www.syfy.com/syfywire/homo-erect...look-human
EXCERPTS: Homo erectus is the oldest ancestor we have with more human than apelike characteristics. It was not the first hominid to stand up, but it started showing significant brain growth and evidence of tool use that set it apart from Australopithecus and earlier Homo species. But just how old is H. erectus?
The answer could be around 2 million. At least that was what paleoanthropologist Ashley Hammond, who recently published a study in Nature Communications, and her team found when they reexamined a prehistoric bone fragment. “We were unsure exactly where the fossil came from,” Hammond tells SYFY WIRE. “We were quite surprised by where a previous study showed its location because it was not where we were expecting it to be.”
[...] After extensive testing ... Hammond concluded that it must have come from these older deposits, meaning it really is 2 million years old. That wasn’t the only thing that surprised them. Foot and pelvis fossils that might have been from the same H. erectus individual also appeared.
“It is likely that they are the same individual since they were found so close together, but we cannot prove this,” Hammond says. “If researchers are able to find additional footbones or pelvic material from early Homo erectus, this would allow critical comparisons of the anatomy that might strengthen our claim.”
If these bones really are from the same individual or even another individual of the same species that is as old as the rocks [...] it could mean that the oldest postcranial (anything below the head) fossils from H. erectus have been found. These fossils are even older than the 1.7-million-year-old H. erectus bones found in Dmanisi, Georgia. However, it is unlikely that this can be proven anytime soon. DNA degrades fast, and any genetic material that might have been in the fossils has long since disintegrated.
Even if they were not from Homo erectus, what could be inferred from the fossils was that they had a more human than apelike morphology, and were almost definitely from some Homo species... (MORE - details)
Denisovan DNA may have aided Pacific migration
https://cosmosmagazine.com/history/palae...migration/
EXCERPTS: . . . By examining the genomes of 317 present-day individuals from 20 populations, the team found that the ancestors of modern-day Pacific populations interbred with little-understood ancient hominins called Denisovans. This genetic mixture seems to have bolstered the immune system and helped these early explorers adapt to living on isolated islands. The results may have implications for the health of Pacific populations today. Thepaper is published in Nature
[...] The populating of the Pacific is one of the most impressive feats of exploration in human history. [...] This enormous region is divided into Near Oceania (including Papua New Guinea, the Bismarck Archipelago and the Solomon Islands) and Remote Oceania (Micronesia, Santa Cruz, Vanuatu, New Caledonia, Fiji and Polynesia).
Our current understanding is that after humans migrated out of Africa, they flowed down through South East Asia, hopping across narrow straights and between islands. From Timor, they used rudimentary rafts or dugout canoes to cross to Papua New Guinea, then headed down the scythed curve of the Bismarck Archipelago, and reached the far edge of the Solomon Islands by around 40,000 years ago. There, nothing but the open ocean lay ahead of them, and so these people – the Near Oceanians – stopped, and Remote Oceania remained uninhabited.
Then some 5,000 years ago, a group of humans from what is now Taiwan left their home shores and journeyed south through the Philippines and Indonesia into Near Oceania. Called Austronesians, they brought with them sophisticated maritime technology and seafaring skills. They mixed with populations of the Near Oceanians, forging a new people – the Lapita – who then struck out to populate the rest of the Pacific.
[...] Previous work has shown that Neanderthal DNA has improved the adaptive capacity of modern humans, with beneficial mutations including those related to skin pigmentation, metabolism, and neural development. This new study now shows that admixture with Denisovans bolstered the immune system of Pacific populations, which may have helped humans adapt to and survive local pathogens when they spread into isolated island environments.
Plus, the mixing between humans and Denisovans didn’t occur just once – at least four independent mixing events occurred with at least two different lineages of Denisovans, as recently as 21,000 years ago. Two of these mixing events occurred after the emergence of the Lapita culture. “Collectively, our analyses show that interbreeding between modern humans and highly structured groups of archaic hominins was a common phenomenon in the Asia-Pacific region,” the authors write in their paper.
[...] this also improves our understanding of the elusive Denisovans, a species for which we have very little fossil evidence... (MORE - details)