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Jean M
09-29-2015, 07:06 PM
http://www.bbc.com/earth/story/20150929-why-are-we-the-only-human-species-still-alive

By Melissa Hogenboom

29 September 2015

Two million years ago in Africa, several species of human-like creatures roamed the landscape. Some looked surprisingly similar to each other, while others had distinct, defining features.

In September 2015, another species was added to the list. Hundreds of bones discovered in a South African cave are now believed to belong to a new species, known as Homo naledi. There may well be many more extinct hominin species waiting to be uncovered.

Our own species appeared around 200,000 years ago, at a time when several others existed. Yet today, only we remain. Why did we manage to survive when all of our closest relatives have died out? ....

For humans, the sharing of symbolic information has been crucial to our success. Every new idea we pick up has the chance to become immortal by being passed down through the generations. That is how language spread, for example.

They found a rut and were stuck in it

The fact that we made any art at all, using the same hands that made all those tools, also points to our unique capacity for behavioural variability, says Shea.

"We do everything more than one distinct way," he says. "Often, the solutions we devise for one problem, we can repurpose to solve a different one. This is something we do exclusively well."

Other ancient hominins seemed to do the same thing over and over again. "They found a rut and were stuck in it."

Did we have a superior brain to thank for this?

... ... Hublin proposes that modern humans, at some point, benefited from key genetic changes.

For the first 100,000 years of our existence, modern humans behaved much like Neanderthals. then something changed. Our tools became more complex, around the time when we started developing symbolic artefacts.

We now have genetic evidence to suggest that our DNA changed at some point after we split from the common ancestor we shared with Neanderthals. When peering into our genetic make-up, there are important differences between us and our Neanderthal and Denisovan relatives. Geneticists have identified several dozen points in our genome that are unique to us, and several of them are involved in brain development.

This suggests that while Neanderthals may have had a similar brain size to ours, it may have been the way our brains developed over our lifetimes that was key to our success.

We don't know what benefits these genetic changes had. But others have suggested that it is our hyper-social, cooperative brain that sets us apart. From language and culture to war and love, our most distinctively human behaviours all have a social element.

Jean M
09-29-2015, 07:10 PM
On this topic (and many others), I can recommend Yuval Noah Harari, Sapiens: A Brief History of Humankind (2015)

http://www.amazon.co.uk/Sapiens-Humankind-Yuval-Noah-Harari/dp/0099590085/

It glitters with insights. I was given it for holiday reading and was gripped.

GTC
01-01-2016, 12:17 PM
In September 2015, another species was added to the list. Hundreds of bones discovered in a South African cave are now believed to belong to a new species, known as Homo naledi.

http://www.anthrogenica.com/showthread.php?6128-NOVA-Documentary-quot-Dawn-of-Humanity-quot-%28covers-discovery-of-Homo-naledi%29