Image: Professor Thomas Suddendorf addresses TEDxUQ, University of Queensland March 2013. Credit: Kyle O’Donovan.
There was a time when tool-making was the characteristic that distinguished us from other animals. It defined the gap between us and other creatures, even our nearest relatives.
This is no longer the case.
Crows use tools and our cousins, the chimpanzees, are celebrated tool-users.
However, we share much more than tool use with the chimpanzees.
In his talk, Clues about the evolution of our extraordinary minds, at TEDxUQ, Professor Thomas Suddendorf said, “of all the creatures on the planet, the two species of chimpanzees have the closest DNA match with us”.
He says that from a chimpanzee’s perspective, “we humans are their closest relatives”.
There is a physical continuity between our species that is easy to accept. As Professor Suddendorf says “our animal heritage” is apparent.
He says Charles Darwin, author of Origin of Species, had reasoned the way to “a physical continuity that was incontestable”.
Humans and other animals “are the same flesh and blood”.
Charles Darwin solved the problem of the evolution of the body. But what about the evolution of the mind?
Professor Suddendorf says that Darwin wrote of his confidence, misplaced and optimistic as it turned out, that psychology would soon provide insights which would solve this problem.
But over the past 150 years Professor Suddendorf says these questions have not been central to psychological inquiry at all.
Recently however, psychology has begun to address Darwin’s problem by “mapping … the mental abilities of our closest relations”.
Humans are able to construct cities, profoundly alter the environment and ask, ‘Who are we?’ Being able to ask that question is linked to our ability to recognise our own reflection.
Why do only some animals have this ability? Or, as Professor Suddendorf asked, “how did they evolve this ability?”
The “parsimonious” or simplest answer says Professor Suddendorf, is that a common ancestor acquired the ability prior to the divergence that led to the four descendant species: gorillas, chimpanzees, orangutans and humans.
The divergence from this last common ancestor would have occurred after the monkeys went their way 18 million years ago and before the orangutans branched out on their own about 14 million years ago.
This suggests that between 18 and 14 million years ago an ancestor common to gorillas, chimpanzees, orangutans and humans developed this trait.
No other family of animals have been shown to have the ability to recognise a reflection of themselves.
“We don’t know what this creature looked like,” said Professor Suddendorf, “but it probably knew what it looked like.”
If we do share this trait because of common descent rather than separate evolution, Professor Suddendorf said “it’s most likely that the neurological basis of the trait is also shared”.
To identity this neurological basis we need to look at “those traits all great apes and humans share,” he said.
Mapping of our brains and the brains of chimpanzees shows the similarities and differences.
“The same must be true for gorillas and orangutans,” said Professor Suddendorf.
They share similarities with us and the chimpanzees. They also have their unique neurological structures.
And, neurologically we all will share a common component or process or structure which allows us to recognise our reflections.
Professor Suddendorf said he thought Darwin would be very happy with these outcomes because there is evidence of continuity.
Monkeys can’t do it, great apes can do it, humans can do it – continuity in the evolution of mind.
This is not to say, of course that our self-awareness is equivalent to the awareness evident in other great apes.”
Perhaps chimpanzees don’t and can’t “think of themselves in the remote past or the remote future.”
It may well be that only humans can undertake mental time travel.
That which is uniquely human “most likely evolved over the past six million years,” after we last shared an ancestor with the chimpanzee lineage.
Scattered across the planet over those six million years were numerous hominid ancestors and relatives.
It is during this time that characteristics such as human language, human culture and human morality evolved within our lineage.
“The evolution of our extraordinary minds,” was underway.
For more about hominid evolution follow the link.
TEDxUQ Profile – Professor Thomas Suddendorf – the widening gap.
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported.
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