Other scientists are studying part of a skull that's from one of the earliest of today's sort of human to leave Africa.
Thinking and Throwing
Back in my 'good old days,' when color television was new, I'd read about eagles having better distance vision than we do, cheetahs being faster than we are, and birds: well, birds flew, and we can't. Not without help, anyway.I don't remember any science textbook coming right out and saying it: but I got the impression that we didn't have much on the ball. Not when it comes to physical abilities.
Sure, we're smart, and we have opposable thumbs: but we're not as fast as ostriches or strong as mules. Some of us are just as stubborn: and that's another topic.
Having a big brain helps: but it's not just about size. Our neural wiring is — different — and I'll get back to that.
Turns out, we're very good at throwing things: and have been for about 2,000,000 years. (July 5, 2013)
"...Greater Admiration...."
I've said this before: a lot. Science and religion, faith and reason, get along fine: or should.
As for the size and age of the universe: we've know that this creation is big and old for a very long time. (Psalms102:26-28; Wisdom 11:22-25)
I'm not upset that God's creation is so much bigger and older than folks thought, when Psalms and Wisdom were written. Even if I was: there's not much point in complaining about it. Besides, scientific discoveries are invitations "...to even greater admiration for the greatness of the Creator..." (Catechism of the Catholic Church, 283)
(Image from NASA, used w/o permission.)
(Wisdom 7:17)
1. Biased Chicks and Phineas Gage
(From Dr Rosa Rugani, University of Padova; via BBC News, used w/o permission.)
("Baby chickens have left-right number bias like humans, say researchers...."
Frame from video provided by Dr Rosa Rugani, University of Padova (BBC News))
"Chicks place low numbers on the left"
Jonathan Webb, BBC News (January 29, 2014)
"Scientists in Italy have found that baby chickens associate low and high numbers with left and right, respectively - just like humans.
"In a series of experiments, 60 newborn chicks were shown patterns of shapes representing different numbers, before choosing a direction.
"Humans are known to use a 'mental number line' to think about quantities but this innate left-right association has not been seen in animals before...."
We've learned quite a bit about how the human brain works since Phineas Gage got in the way of a high-velocity tamping rod on September 13, 1848.His improbable survival got called "the American Crowbar Case:" but the iron tamping rod was a pointed cylinder, three feet seven inches long. It looked like a javelin.
The accident destroyed Phineas Gage's left frontal_lobe. We're still working out exactly what that part of the brain is for: it's apparently where we do a lot of our thinking.
Phineas Gage recovered to the point where he was hired as a stagecoach driver, and lived nearly 12 years after the accident. The facts of his case, including real changes in his behavior, weren't nearly as exciting as the stories written about him.
Getting back to chicks, numbers, and brains:
"...Dr Rossa Rugani, who led the experiments at the University of Padova, said it was impossible to know exactly what drove the chicks' choices - but the results were clear.
" 'All we can judge is behavioural responses. Therefore, we don't actually know if it is a real 'number line' but it strongly resembles what is observed in the human number line,' she told BBC News...."
(Jonathan Webb, BBC News)
Left, Right, and Brains
(From Popular Science (November 1874) and Outline of the human nervous system, Wikimedia, used w/o permission.)
Oysters, dragonflies, wombats, and humans, are wired pretty much the same way. The left and right sides of our nervous system are mirror-images of each other, almost; and there's generally a big bundle of nerves at the end with a mouth and the major sense organs.
That could be a result of convergent evolution: things looking alike, because they're used the same way.
On the other hand, some similarities probably happen because the critters had a common ancestor. Spotted gar, mice — and humans — use the same genetic code for growing fins, paws, and hands: because upwards of 300,000,000 years back we had a common ancestor. (December 26, 2014)
Like I've said before, life's molecular machinery is very modular. (November 22, 2013)
That's why scientists could patch code from bacteria into tobacco plants and potatoes: letting the plants produce their own pesticides. That sounds spooky, but horizontal gene transfer happens naturally: and most likely has been for billions of years. And yes — bacteria have been around that long.
I was going somewhere with this. Let me think. Spotted Gar. Oysters. Wombats. Right.
Maybe complex nervous systems have left and right sides, and a brain at one end, because that's an optimal design.
But when birds and humans both seem to process numbers the same way — that could easily be because a common ancestor had a hardwired 'number line.' That's what Dr. Rosa Rugani says. Or we could be looking at a whacking great coincidence.
Not everybody has the left-small/right-large number line. Adults who read and write Arabic, for example, put large numbers on the left. (BBC News)
On the other hand, most folks pay slightly more attention to stuff on our left, and start counting from the left side. Since we're not chickens, we can learn whatever counting and organization systems our cultures use: No surprises there.
'It happened earlier than we thought' seems to be a recurring theme in science. Fuxianhuia brains, for example, are organized the same way — basically — as today's arthropods: and that's another topic. (July 25, 2014)
2. Pioneers: 55,000 Years Ago
(From BBC News, used w/o permission.)
("The individual lived close to the time when modern human migrants interbred with Neanderthals"
(BBC News))
"Skull clue to exodus from Africa"Although it's technically accurate, and I can't think of an appropriate alternative, I still don't like the term "interbreeding" in this context. Maybe it's because of the "he doesn't have family, he's Irish," remark made by one of my ancestors about another. (December 12, 2014; October 31, 2014)
Paul Rincon, BBC News (January 28, 2014)
"An ancient skull discovered in Israel could shed light on the migration of modern humans out of Africa some 60,000 years ago.
"This migration led to the colonisation of the entire planet by our species, as well as the extinction of other human groups such as the Neanderthals.
"The skull from Manot Cave dates to 55,000 years ago and may be the closest we've got to finding one of the earliest migrants from Africa....
"...[London Natural History Museum human origins research leader, Chris] Stringer, who was not involved with the study, added: 'Its discovery raises hopes of more complete specimens from this critical region and time period.'
"The find is also of interest because this individual lived at around the time when modern humans are thought to have interbred with Neanderthals.
"All non-Africans possess a small amount of Neanderthal ancestry, pointing to an interbreeding event just after modern humans left their homeland but before they diversified into different populations.'..."
The good news is that anthropologists and paleontologists seem to be getting over the notion that one must look 'Anglo-Teutonic' to be intelligent, and are piecing together an increasingly-detailed picture of humanity's family tree.
I'm "non-African," as the article put it: so some of my ancestors are Neanderthals. Although we're still calling Neanderthals and other folks who'd have a hard time blending into a crowd these days other "species" — I won't be surprised if a few years from now that changes.
My guess, looking at the genetic heritage we share with Neanderthals, Denisovans, and others, I'm guessing that we're all one species — and living in an era where ethnic differences are remarkably minimal. (December 12, 2014)
"Gracile:" Comparatively
"Gracile" — maybe this is obvious, nor maybe not — means "gracefully slender." Maybe it's hard to think of folks like Khadzhimurat Akkayev and Ewa Mizdal as "gracefully slender," but on average we're nowhere near as sturdily-built as my Neanderthal forebears." 'The skull is very gracile - there is nothing that makes it any different from a modern skull,' Prof Israel Hershkovitz, from Tel Aviv University, told the Nature podcast.
" 'But it also has traits that are found in older specimens.'
"He added: 'This is the first evidence that shows indeed there was a large wave of migrants out of East Africa, crossing the Sahara and the Nubian desert and inhabiting the eastern Mediterranean region 55,000 years ago. So it is really a key skull in understanding modern human evolution.'
"Physical features of the skull, such as a distinctive 'bun-shaped' region at the back, resemble those found in the earliest modern humans from Europe.
"This 'implies that the Manot people were probably the forefathers of many of the early, Upper Palaeolithic populations of Europe', Prof Hershkovitz said.
"Chris Stringer, research Leader in human origins at London's Natural History Museum, commented: 'Manot might represent some of the elusive first migrants in the hypothesised out-of-Africa event about 60,000 years ago, a population whose descendants ultimately spread right across Asia, and also into Europe.'..."
(Paul Rincon, BBC News)
Folks who look like the current model have been around for about 200,000 years, but we apparently didn't leave our African homeland until — as scientists quoted in the BBC article said — 60,000 years back, more or less.
That's the earliest that we know of so far, anyway.
That's when we met folks whose ancestors had left earlier: lots earlier, in some cases. They didn't look like us, quite: but I gather that they had at least one uniquely human trait, the SRGAP2 gene. And that brings me back to our brains.
Uniquely Human Genes
SLIT-ROBO Rho GTPase-activating protein 2 (srGAP2) (the formin-binding protein 2 (FNBP2)) is a protein that's encoded by the the SRGAP2 gene. (There will not be a test on these words.)
Scientists are still working out exactly what dendritic spines do: it looks like they're involved in connecting neurons to each other, transmitting and recording data, and maybe analyzing signals between neurons.
We're very much in the 'might, could be, or maybe not' stage of sorting out how our brains are wired, and what the components do. Considering that it's only 166 years, seven months, and a few odd days, since Phineas Gage's accident — I think we're doing pretty well.
More:
- Human evolution
Wikipedia - SRGAP2
Wikipedia - What Does it Mean to be Human?
Smithsonian Institution's Human Origins Program
- "Precision-Grip Thumbs and and A 'New' Archosaur"
(January 30, 2015)
Particularly - "Found: Genes for Fins, Paws, and Hands"
(December 26, 2014)
Particularly - "Homo Erectus Engraving, Long-Lost Relatives"
(December 12, 2014)
Particularly - "Dinosaur Arms, and Ust'-Ishim Man's DNA"
(October 31, 2014)
Particularly - "Coping With Change for Millions of Years; Chatty Chimps"
(July 11, 2014)
Particularly
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