Will we survive our brain..

Found a interesting article last night from 2007, some of you might like it.



Will we survive our brain? - Features - The Lab - Australian Broadcasting Corporation's Gateway to Science


---

​

The human cerebral cortex has grown rapidly over the last million years. With it, we've learned to use tools, industrialised, and built nuclear weapons. But the older, primitive parts of our brain are still there-fuelling our emotions, our fears, our greed, our impulse to destroy our neighbours. Peter Lavelle asks can the old and the new brain learn to coexist before we destroy ourselves?​

​

Humans have the greatest ratio of brain to body mass of any animal. What separates us most from other creatures on the planet is the size of our brain. One hundred billion nerve cells, packed into 1400 cubic centimetres - bigger than any other species. Thanks to it, we're the dominant species on the planet-forget the huge jaws and the sharp spines running down the back, who needs them?
It's been a long time in the making though. About a billion years ago, brains were pretty basic-just groups of specialised cells with the ability to transmit electrical signals to move other groups of cells-primitive limbs. The idea was, in an environment where an organism needed to get away in a hurry from another on the lookout for a snack, mobility was a good idea.
Another good idea was the ability to sense the surrounding environment-sounds, light patterns, temperature, chemical composition, to detect whether predators were around. So sensory receptors developed and it made sense to have them in close proximity to the cells that controlled movement. Other groups of cells developed into specialised structures that generated emotions, called the limbic system. Others relayed messages down a spinal column towards the distant limbs.
What a package, when you put it all together. A stimulus from the environment (a threat, an opportunity to get food, or reproduce), generated an emotion, leading to a physical action-flight, attack, pursuit.
Even if you grew to the size of a giant lizard, this was basically all you needed. Your average tyrannosaurus had a brain of only a little over 100 cubic centimetres. (But with jaws that size, who argued?)
Then, from about 200 million year ago, in mammals, the brain began to sprout an area called the neocortex, or new cortex. With this came the ability to deliberate, reason and plan ahead. Growth in the neocortex size was largest in the primates, especially the great apes, and especially in the line that went on to become humans. From the period of the early hominids of two million years ago to modern homo sapiens of 500,000 years ago, the neocortex tripled in size-and most of the growth was in the area at the front called the frontal lobes.
A new life on the savannah

Why this all happened is something of a mystery. The period of raid expansion took place in a period of cooling in East Africa, when forests receded and the primates were forced out of the trees and onto the open plain, the savannah, where it was easier and faster to travel in search of food on two legs, freeing up the hands to make tools.

Bone and stone tools from Blombos Cave. Increased brain capacity paved the way for the development of tool making. Photo: The National Geophysical Data Center Tricky stuff, making tools-you needed extra brain capacity. Also, hunting was easier if you did it in groups; cooperation needed some sort of communication, grunting and gesturing wasn't enough, you need verbal exchanges, even if purely functional.
These skills need massive amounts of brain capacity to pull off. The brain got so big that the original brain stem in homo sapiens is almost completely enveloped by the neocortex. We have the largest ratio of brain weight to body weight of any species on earth.
Then, from the frontal lobes of the neocortex came a new feature-consciousness-that awareness of self, which we think first appeared about 60,000 years ago, because it's from that time we began to conduct elaborate rituals to bury our dead, revealing for the first time a belief in the afterlife.
Consciousness, and with it the ability to plan ahead, to anticipate and to reason, allowed us to step out of our previously narrow ecological niche. So much so that from about the end of the last ice age about 10,000 years ago, we left the plains and the forests and settled into communities in the great river valleys of the Levant and India.
The rest is (recorded) history. We stored surplus food. We started writing things down. We built cities. Machines to replace labour. Invented money, double entry bookkeeping and the joint stock company.

The Byzantinian monument of St Sophia in Istanbul. Art is one of the greatest triumphs of the neocortex. Photo: Reuters Thanks to the processing power of the neocortex, humans have been the dominant species on the planet ever since. No other species can even approach the same ability to make technological improvements to its environment.
Last century, we reached the Moon, split the atom, built skyscrapers, and mapped the human genome.
Grumpy old brain

But some scientists say the development of the cortex has been too rapid. It's happened in a blink of an eye in the evolutionary time scale.
But while the cortex may have enlarged so much as to envelop the older structures like the limbic system, those older structures have remained unchanged for hundreds of millions of years.
For these scientists, homo sapiens are still on the lookout for the sabre tooth tiger at the cave entrance and the enemy tribe across the river. The limbic system is still reacting to stimuli the way it always has; with fear, anger and hostility, sexual attraction, and the desire for territory.
These older parts of the brain play a much larger role in our thought processes than we believe-but they're working below the threshold of consciousness, argues Stanford University professor Robert Ornstein in his book, The Evolution of Consciousness: The Origins of the Way We Think. He argues that the archaic brain dictates many of our responses to the day-to-day world. So when we get angry, scared, and aggressive, as we do in a range of day to day situations, it's the primitive parts of our brains at work.
And they're making life difficult for us, argues Ornstein. The old primitive parts, so necessary to fight off the sabre tooth tiger or the tribe across the river, are totally unsuited to the 21st century of industrialisation, mega cities and nuclear power.

The 'mike shot' was the first hydrogen bomb tested in 1952. The island where the bomb was detonated was vaporized. Photo courtesy of National Nuclear Security Administration / Nevada Site Office One of the greatest human achievements of last century was the splitting of the atom to produce a nuclear chain reaction that created enormous amounts of energy. That was our cortex at its finest. And how did our more primitive instincts view it? What a great idea for a bomb!
Five times last century the human species came close to nuclear annihilation from nuclear weapons. The closest was in 1963 during the Cuban Missile Crisis when during the US blockade off the coast of Cuba, US navy ships bombarded a Soviet nuclear sub, which almost fired its nuclear weapons, but decided to surface and surrender instead, avoiding a nuclear Armageddon.
Around the world there are still tens of thousands of nuclear weapons and hundreds of tons of plutonium and enriched uranium, potentially accessible to terrorists or rogue states.
This century we face another threat-climate change. Our airconditioned McMansions and our 4WDs are two more triumphs of the frontal lobes, but the C02 they add to the atmosphere threatens to raise global temperatures by five to nine degrees Celsius, turning temperate zones into deserts and displacing if not killing 90 per cent of the world's human population by 2100, argues British scientist and founder of the Gaia hypothesis James Lovelock, in his book The Revenge of Gaia.
Can we survive?


Dominating the planet. Here the lights of human cities are imaged by satellite. Photo: NASA Thanks to our consciousness and our reasoning abilities, we're well aware of the dangers. But so powerful are our old instincts that we may not be able to avert them.
Edward 0. Wilson, biologist and professor of entomology at Harvard University, in an essay Is Humanity Suicidal? (published in a collection entitled In Search of Nature), wrote that the brain evolved over a long period when our ancestors were hunter gathers, life was short, you focused on the near future; getting food and reproducing and little else.
Nothing much has changed today, he argued. "We are tribal and aggressively territorial, intent on private space beyond minimal requirements and oriented by selfish sexual and reproductive drives," he wrote.
Here are some excerpts:
"Individuals place themselves first, family second, tribe third and the rest of the world a distant fourth ... people are programmed by their genetic heritage to be so selfish that a sense of global responsibility will come too late. It was a misfortune for the living world in particular ... that a carnivorous primate and not some more benign form of animal made the breakthrough. Perhaps a law of evolution is that intelligence usually extinguishes itself."
In this scenario, humankind evolves until it's clever enough to destroy itself, and it's the primitive impulses hidden below the cortex that do the detonating.
Altruism

But other scientists say this scenario doesn't take into account the social organisation of the human species that's arisen since we gave up hunting and gathering.
They say that a precious and very human trait may yet save us - altruism.

Humans often put their own wellbeing at risk to assist other humans. Photo: Reuters Altruism is when members of a species put aside their immediate needs-and may even suffer in the short term-for a greater good that will benefit the group as a whole.
Other mammals such as chimpanzees and dolphins, birds, and even insects show altruistic traits, but altruism is more developed in homo sapiens than any other species.

And there's evidence that we're becoming more altruistic as time goes on. Members of a species typically only show altruism to their own tribe-the enemy tribe over the river are still the enemy.
But over the last ten thousand years ago or so of human civilisation, the 'tribe' has gradually been getting bigger. Thanks to another by-product of the frontal lobes of the neocortex, the advanced form of social organisation we call 'culture', we've become more and more dependent on each other. The 'tribe' has enlarged-from the village, to the city, the nation state, the trading block, and now in the 21st century, the global village.

The New York Stock Exchange: No enemies, only clients. Photo: Reuters Global institutions, international treaties, the opening up of global trade and financial markets, and the mass media, have interconnected us and diminished tribal differences that formerly made us enemies. They make it increasingly difficult for us to act in destructive, aggressive ways without indirectly harming ourselves.
Global treaties like the Kyoto Protocol and the Nuclear Non-Proliferation Treaty might just be signs that we can address the problems created by our cerebral cortex.
Or maybe not. If you're from another galaxy, having recovered this story from a rusty hard disk buried in a lifeless desert on the planet formerly known as Earth, we can only say that it seemed like a good idea at the time.