Posted on 03/21/2002 5:49:37 PM PST by blam
Week of March 16, 2002; Vol. 161, No. 11
Heads Up: Problem solving pushed bright primates toward bigger brains
Bruce Bower
Progressively larger brains evolved in primates of all stripes, not just humans. We can thank a common capacity for solving a broad range of problems, from coordinating social alliances to inventing tools, according to a new study.
This conclusion challenges a popular theory that big, smart brains arose primarily because they afforded advantages when it came to negotiating complex social situations during human evolution.
"The ability to learn from others, invent new behaviors, and use tools may have [also] played pivotal roles in primate-brain evolution," say Simon M. Reader of McGill University in Montreal and Kevin N. Laland of the University of Cambridge in England. In an upcoming report in the Proceedings of the National Academy of Sciences, the two zoologists chronicle links between an array of intelligent behaviors and enhanced brain size in primates.
Reader and Laland examined approximately 1,000 scientific studies of behavior in 116 of the world's 203 known primate species. They identified 553 instances of animals discovering new solutions to survival-related problems, 445 observations of individuals learning skills and acquiring information from others, and 607 episodes of tool use.
The researchers then consulted previously obtained data on brain size relative to body size in different primates. In particular, they focused on the volume of the structures that make up what scientists call the executive brain, a frontal region thought to be crucial for complex thinking.
Species that have the proportionately largest executive brains are the ones that most often innovate, learn from others, and use tools, Reader and Laland contend. These three facets of intelligence vary together as primate brains enlarge, they say. There's no evidence in any species of an evolutionary trade-off between these traits, such as an increase in innovation accompanying a decline in social learning.
A related report by neuroscientist Barbara L. Finlay of Cornell University and her colleagues concluded that different brain regions in mammals enlarged all together during mammalian evolution, not in piecemeal fashion related to specific functions. Whole-brain evolution was driven by changes in the timing of early brain development in individuals, says Finlay. In all species, late-generated structures—including the executive brain—have grown the largest, Finlay's team asserted in the April 2001 Behavioral and Brain Sciences.
Reader and Laland provide "important new evidence" that wide-ranging thinking skills shared by many primate species encouraged the evolution of large brains, comment psychologist Robert M. Seyfarth and biologist Dorothy L. Cheney, both of the University of Pennsylvania in Philadelphia, in a comment published with the new report.
They suggest that intellectual accomplishments unique to people, such as language use, may have played a smaller role in the evolution of our sizable brains than has often been thought.
As always, words like "arose suddenly in substantially its present form", or "evolved rapidly with few if any intermediate stages".
More of the Punctuated Equilibrium or Hopeful Monster nonsense.
Evolutionary Biology has all of the meaning of a beer-induced dorm bull session.
Question: what is the most important gift any father can give to his children?
To love their mother!
All the time...
Don't worry, we're not in danger yet.
Yeah?
I don't llike the new seperate forums. They could have just kept one forum, but color-coded General Interest differently from News threads, for easy searching.
It's a cool article, and FR is better off not Balkanized.
All the time...
People have always said that.
The article only points out that one region of the brain did not likely get way out in front of the others in the march to bigger brains. The regions coevolved because the species has to stay fit, after all. The different brain areas are mutually dependent.
:>)
I am gearing up for anti-bushbots/Clinton is a nice guy/next 3 years.
Doesn't this blow the Theory of Evolution to smithereens? All mammal brains enlarged? All mammals weren't facing the same pressure on survival. They don't know squat.
Uh, the article does NOT say "all mammal brains"--it says "all PRIMATE brains"--which is a whole different thing. PRIMATES are the very tiny branch of mammals to which H.S.S. (homo sapiens sapiens) belongs. It is not particulary surprising that a similar evolutionary feature is found there, and in no way "blows evolution to smitereens". If anything, the finding SUPPORTS evolution.
The Frog version starts with "Plus ça change . . ."
No. All it says is that the basic mutation that pushed the primates toward an emphasis on brain-power applied to problem solving occurred much earlier in evolution than initially thought. OF COURSE they faced different situations--that is why they are different today.
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