When it comes to my science posts, I will search and find something I find interesting, and then leave that tab open on my browser until I have the chance to use it. However, other topics also come up, and so there is often a delay that occurs between my finding an interesting science item and my writing about it.
With the political situation as it is, I’ve had way too many other topics to write about, and it’s gotten to the point where I now have more than 2 dozen tabs open on my browser, some of them for more than a year. So I better start posting science again.
This story caught my eye back in 2017, but if it ever got posted here, I never saw it. (Search pulls up nothing.)
For some years now, the generally accepted scenario for the origin of our species, homo sapiens, is that it arose about 200,000 years ago in east Africa. That view has recently been challenged by the analysis of fossils discovered in Morocco. These fossils look surprisingly modern, and date to 300,000 years ago, extending the potential period of existence of our species by 50 %! These results also suggest that, rather than being confined to east Africa, early humans were evolving all across Africa during this period. There’s more below the fold…
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Back in the early 1960s, early hominid fossils were found in a former barite mine in a region of Morocco called Jebel Ihroud. At the time, these fossils were thought to be about 40,000 years old, representing some minor late-surviving variant of the human line. (The specimen had been described as the “African Neanderthal” despite the fact that it shares more characteristics with modern humans than actual Neanderthals.)
Paleontologists returned to that former mine starting in the 1990s into the present. They’ve found more specimens, of both fossils and stone tools, and have brought to bear modern methods for dating them. The result that the fossils were 300,000 years old, rather than 40,000, came as a big surprise, and has required a change in the way archaeologists regard the origins of our species. Their technology is established as the earliest appearance of Middle Stone Age tools. Their own appearance is very nearly modern. Said Jean-Jacques Hublin (a principal investigator and director of the department of human evolution at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany)
The face of these people is a face like my face; it's a face (like) somebody you could cross in the street today.
But there are significant differences between these ancient people and ourselves, mostly in terms of brain development. While the brain size of the specimens of Jebel Ihroud is only a little smaller than the size of the modern human brain, the biggest changes are suspected to be in the wiring of that brain. Hublin says
Recent discoveries in paleogenetics and genetics show that in this time period, there were a series of mutations affecting brain functioning, brain connectivity, brain development that occurred within our lineage. It seems to be something specific to our species that we don't find in other groups of the same period, like Neanderthals or Denisovans or others.
It’s important to keep in mind that this doesn’t necessarily change the focus of early human evolution from east Africa specifically to Morocco. The implication of this discovery is that there were likely many communities of early Homo sapiens variants across all of Africa. They would have been able to move around the continent quite easily. (Keep in mind that at this time the Sahara was a lush grassland.) It will be a grand challenge for paleontologists to find others, given how rare such specimens are, but it stands to reason that they are out there somewhere.
On to the comments!
Top Comments (August 14, 2019):
From silverfoxcruiser:
This comment by sawgrass727, on Trump’s prodigious lying during his most recent speech in Pennsylvania, specifically, this portion:
What I wish: The media would just turn off the spigot of reporting and commenting on his lies. Just sum up a speech with a set of facts like,
“At a speech today in Pennsylvania which likely violated the federal Hatch Act, Trump told about 25 lies, some old and some new, and included racist overtones. He concluded the speech by proudly admitting it was non-presidential.”
From durrati’s recommended post collecting David Dale’s tweets of the speech.
From ZenTrainer:
This comment by AZsparky on the importance of local elections (larger font requested by submitter):
And, it is always good to keep in mind that state, county, local elections are equally important as those on the national level. Republicans understood that long ago. Now Democrats are having to play catch-up in that regard. Running good candidates such as Mr. Jones and so many others in offices around the country is inspiring. Truly, Democrats are the firewall against a fascist America.
From ZenTrainer’s recommended post.
From Elizawhig1:
This comment from Breather in Laura Clawson’s front page post on Ken Cuccinelli’s rewrite of Emma Lazarus.
From belinda ridgewood:
Hunter wrote a splendid diary about "Trump's team of bottom-feeding suction eels" taking money to speak to conventions of Q-trolls, and Its the Supreme Court Stupid came up with a new lyric to an old song to describe the situation.
Top Mojo (August 13, 2019):
Top Mojo is courtesy of mik! Click here for more on how Top Mojo works.
Top Photos (August 13, 2019):
Thanks to jotter!