By Trace L Hentz
We are ANCIENT ANCIENT. Yes, indeed. Older than we know, or were told... which is why so many confusing theories are out there, and some people make money on degrees and titles with their theories.
@juliatreciak926
I’m about to have a stroke thinking about how old this planet is.
👇 THIS: (YOUTUBE) Some commenters have pointed out that calling Neanderthals and Denisovans “other hominin species” in this episode breaks the rules of the biological species concept (BSC), which says if two things can interbreed, then they’re the same species. Some paleoanthropologists would agree. They consider both Neanderthals and Denisovans to be subspecies of Homo sapiens, rather than separate species. Other experts would say that Neanderthals have a set of features that make them clearly distinguishable from Homo sapiens, putting them outside the range of variation we include in our species. And we hardly know the Denisovans - like we said in the video, they don’t even have a scientific name yet. The incredible thing about this is that we can even think about applying the BSC to fossils at all. The BSC is a species concept based on living organisms, and it’s only been within the last two decades or so that we’ve had the ancient DNA and the technology to test hypotheses about interbreeding in extinct groups. And it’s not the only way to define a species, either, so it will likely be a while (if ever) before anthropologists decide whether we’re a different species, subspecies, or population from the Neanderthals and Denisovans. (Darcy Shapiro, PhD, script editor)
More Theory? GHOST DNA?
YES...Ghost DNA...
About 50,000 years ago, ancient humans in what is now West Africa apparently procreated with another group of ancient humans that scientists didn't know existed. There aren't any bones or ancient DNA to prove it, but researchers say the evidence is in the genes of modern West Africans. They analyzed genetic material from hundreds of people from Nigeria and Sierra Leone and found signals of what they call "ghost" DNA from an unknown ancestor.
The findings on ghost DNA, published in the journal Science Advances, further complicate the picture of how Homo sapiens—or modern humans—evolved away from other human relatives. The scientists analyzed the genomes of 405 West Africans. Sriram Sankararaman, a computational biologist at UCLA, says they used a statistical model to flag parts of the DNA. The technique "goes along a person's genome and pulls out chunks of DNA which we think are likely to have come from a population that is not modern human."
50,000 Years Ago—Who Slept With Whom?
The unusual DNA found in West Africa isn't associated with either Neanderthals or Denisovans. Sankararaman and his study co-author, Arun Durvasula, think it comes from a yet-to-be-discovered group.
"We don't have a clear identity for this archaic group," Sankararaman says. "That's why we use the term 'ghost.' It doesn't seem to be particularly closely related to the groups from which we have genome sequences from." The scientists think the interbreeding happened about 50,000 years ago, roughly the same time that Neanderthals were breeding with modern humans elsewhere in the world. It's not clear whether there was a single interbreeding "event," though, or whether it happened over an extended period of time.
The unknown group "appears to have split off from the ancestors of modern humans a little before when Neanderthals split off from our ancestors," he says.
So what happened to this mysterious group of ancient humans? Scientists aren't totally sure. They might have died off, or they might have eventually been completely subsumed into modern humans.
From my book: WHAT JUST HAPPENED (2021) (978-057886725-0)
No comments:
Post a Comment
Please: Share your reaction, your thoughts, and your opinions. Be passionate, be unapologetic. Offensive remarks will not be published. We are getting more and more spam. Comments will be monitored.
Use the comment form at the bottom of this website which is private and sent direct to Trace.