Unexpectedly speedy expansion of human, ape cerebellum

brain
Left hemisphere of J. Piłsudski's brain, lateral view. Credit: public domain

A new study published in the Cell Press journal Current Biology on October 2 could rewrite the story of ape and human brain evolution. While the neocortex of the brain has been called "the crowning achievement of evolution and the biological substrate of human mental prowess," newly reported evolutionary rate comparisons show that the cerebellum expanded up to six times faster than anticipated throughout the evolution of apes, including humans.

The findings suggest that technical intelligence was likely at least as important as social intelligence in human cognitive evolution, the researchers say.

"Our results highlight a previously unappreciated role of the cerebellum in ape and human brain evolution that has the potential to refocus researchers' thinking about how and why the brains in these species have become distinct and to shift attention away from an almost exclusive focus on the as the seat of our humanity," says Robert Barton of Durham University in the United Kingdom.

The cerebellum had been seen primarily as a brain region involved in movement control, adds Chris Venditti of the University of Reading. But more recent evidence has begun to suggest that the cerebellum has a broader range of functions. The cerebellum also contains an intriguingly large number of densely packed neurons.

"In humans, the cerebellum contains about 70 billion neurons—four times more than in the neocortex," Barton says. "Nobody really knows what all these neurons are for, but they must be doing something important."

The neocortex had gotten most of the attention in part because it is such a large structure to begin with. As a result, in looking at variation in the size of various brain regions, the neocortex appeared to show the most expansion. But much of that increase in size could be explained away by the size of the animal as a whole. Sperm whales have a neocortex that is proportionally larger than that of humans, for example.

By using a comparative method that controlled for those differences in the way the two structures correlate, Barton and Venditti uncovered a striking pattern: both nonhuman apes and humans depart from the otherwise tight correlation in size between the cerebellum and neocortex found across other primates due to relatively rapid evolutionary expansion of the cerebellum.

Barton and Venditti say that the cerebellum seems to be particularly involved in the temporal organization of complex behavioral sequences, such as those involved in making and using tools, for instance. Interestingly, evidence is now emerging for a critical role of the cerebellum in language, too.

While plenty of work remains, the new study establishes the as "a new frontier for investigations into the neural basis of advanced cognitive abilities," the researchers say.


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More information: Current Biology Barton et al.: "Rapid evolution of the cerebellum in humans and other great apes." www.cell.com/current-biology/a … 0960-9822(14)01069-0
Journal information: Current Biology

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Citation: Unexpectedly speedy expansion of human, ape cerebellum (2014, October 2) retrieved 21 July 2019 from https://phys.org/news/2014-10-unexpectedly-speedy-expansion-human-ape.html
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NOM
Oct 02, 2014
Go away and post this drivel on a fundie site troll.

Oct 02, 2014
Verkle, it's unexpected because it's a discovery you tard.
A lot of things can happen in 4000000000 years
If you are all about God, why do you deny his creation?
And it is not scientific to call the human brain advanced beyond all other species, dolphins for example have both larger and more wrinkly brains than us, a wrinkly brain increases the surface area, there by increasing complexity by some measures.
And it's not completely random in the sense that you seem to be alluding to, the mechanism is random, just like getting cancer, but you succeed in your environment based on those random rolls. ones that are useful, like a stone coloring on a lizard prevent a hawk from eating it compared to his green brother, so the stone colored one lives and passes his genes and his brother becomes lunch.

But you don't care, and that's why your world view is dead in modern societies except America, because you can't adapt to facts.

Oct 02, 2014
@verkle - once again STOP posting drivel. We don't go into churches and scream 'liar liar' every single time a preacher speaks. Show science the same respect and go away!.

Oct 03, 2014
There's a theory of mind by cognitive Neuroscientist George Lakoff that postulates some division of brain architecture with reasoning and control of procedural memory for motion control as metaphor for our reasoning that seems to be what the article is referring as tying this all together. Also, didn't they recently discover a gene that allowed humans to more quickly and easily convert observed behavior and cognitive behavior into complex movement patterns?

Oct 03, 2014
"We don't go into churches and scream 'liar liar' every single time a preacher speaks."

Maybe skeptics and other science supporters should do that. And then they protest, say that we are simply returning their trolls in good spirit. =D

Actually, besides anti-science trolls immorally trying to confuse or disrupt communication, education and science for their own selfish purposes, it is shameful that there are entire organizations devoted to lying. :-/ But we do have free expression/free religion, so as elsewhere in human rights one must take the bad with the good.

@ODesign: When they do fMRI or even better, use see through animals and fluorescence, they see signals all over. The brain hasn't evolved to be simple, but functional.

But when they see these correlations, it promises some form of recognizable functional division. One may hope.

Oct 03, 2014
"The findings suggest that technical intelligence was likely at least as important as social intelligence in human cognitive evolution, the researchers say."

-Not only technical intelligence but the manner in which it was spread, is what forced our brains to grow.

Tribes whose members were better able to cooperate and communicate in anticipating an enemys movements, and to devise complex plans to outwit and overcome these enemies in the field, would be expected to prevail in battle. The victors would kill all the males and incorporate all the females - another reason for legalized polygamy.

This process grew our brains far faster than natural selection ever could. They grew unnaturally large. Our heads are too big to fit through the birth canal and so we are born prematurely, with great pain and danger to the mother. She cannot birth by herself, needing assistance from a midwife, and usually dying in childbirth.

There is nothing natural or sustainable about our brains.

Oct 03, 2014
none of this nonsense really makes sense. It is ABSOLUTELY UNFEASABLE that all of this could have happened by chance and time alone
Why verkle I am surprised that this process of enhanced development through intertribal conflict wouldnt have occurred to you - it is the main subject line of the entire old testament.

"2 Now Balak son of Zippor saw all that Israel had done to the Amorites, 3 and Moab was terrified because there were so many people. Indeed, Moab was filled with dread because of the Israelites... "This horde is going to lick up everything around us, as an ox licks up the grass of the field."

"10 Who can count the dust of Jacob
or number even a fourth of Israel?" num22-24

-The old testament describes succinctly how to generate maximum efficiency in the tribal dynamic, and then to use it to conquer and establish an empire. And the new testament describes how to stage revolution for the same purposes. Throughout, the solidarity of the tribe is all-important.

Oct 03, 2014
I left out the part about the talking donkey.

Interesting, I had forgotten about this passage:

"19 God is not human, that he should lie,
not a human being, that he should change his mind.
Does he speak and then not act?
Does he promise and not fulfill?" num23

-But his book is full of things we know never happened. Why did he lie about them verkle? Why did he go to so much trouble to make it look as if evolution is real, if it is not?

Why would he try to deceive us so profoundly... and then fail?

Oct 03, 2014
I keep re-setting to No Comments and Phys Org ignores it. Comments used to be civil and informative on this site, but now they are nothing but endless trolling, insults, rants by people who are hostile and permanently angry, and in some cases mentally disturbed and unable to speak in connected sentences. So I went to settings, and reset for No Comments. But the management doesn't care what goes on here. They don't keep their software up, so a re-set doesn't stick. A new list brings all the inane ugliness back into view. There is no way to contact the management that I can find. Perhaps there is no management at all. But if anyone knows how to set the settings to NO COMMENT, and make the new settings actually stick - please let me know.

Oct 03, 2014
Hey dm

You think physorg cares whether you want to read the comments or not? Are you saying that because you cant turn them off you cant refrain from reading them? Are you really that compulsive??

Oct 04, 2014
@dollymop
Are you setting the "Hide all comments by default" to Yes under the "Default display mode" entry? That definitely works.

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