Tuesday, November 20, 2012

Brain in Decline?





 This conjecture is rubbish of course, but it entertains. We have not begun to systematically optimize the human brain at all. Such optimization may even try DNA adjustment in the future.

Where we have a serious weakness is that our education system is multiply flawed let alone focused on the core objective of optimizing any child's brain. That objective is not even recognized.

What happens instead is that the child makes choices that help or hinder him for the balance of his life.

It is clear to me that all skills can be brought up to optimal levels in everyone. Some may well take a lot longer but that is irrelevant. Taking two years to perfect memory skills as compared to a standard of six months is meaningless if it then allows you to complete a history and law degree.

The other weakness in our education system is that low skill levels make information gathering difficult. If you read all extant material on a subject and clearly understand all read and then discuss with others, odds are you will be on the top of your game and your brain will produce surprises. None of this is going to happen if your reading comprehension is flawed.

Brain development has two phases. Skill development to a high level and application to polish those skills and acquire data.

Human intelligence 'peaked thousands of years ago and we've been on an intellectual and emotional decline ever since'

STEVE CONNOR

MONDAY 12 NOVEMBER 2012


Is the human species doomed to intellectual decline? Will our intelligence ebb away in centuries to come leaving our descendants incapable of using the technology their ancestors invented? In short: will Homo be left without his sapiens?

This is the controversial hypothesis of a leading geneticist who believes that the immense capacity of the human brain to learn new tricks is under attack from an array of genetic mutations that have accumulated since people started living in cities a few thousand years ago.

Professor Gerald Crabtree, who heads a genetics laboratory at Stanford University in California, has put forward the iconoclastic idea that rather than getting cleverer, human intelligence peaked several thousand years ago and from then on there has been a slow decline in our intellectual and emotional abilities.

Although we are now surrounded by the technological and medical benefits of a scientific revolution, these have masked an underlying decline in brain power which is set to continue into the future leading to the ultimate dumbing-down of the human species, Professor Crabtree said.

His argument is based on the fact that for more than 99 per cent of human evolutionary history, we have lived as hunter-gatherer communities surviving on our wits, leading to big-brained humans. Since the invention of agriculture and cities, however, natural selection on our intellect has effective stopped and mutations have accumulated in the critical “intelligence” genes.

I would wager that if an average citizen from Athens of 1000BC were to appear suddenly among us, he or she would be among the brightest and most intellectually alive of our colleagues and companions, with a good memory, a broad range of ideas and a clear-sighted view of important issues,” Professor Crabtree says in a provocative paper published in the journal Trends in Genetics.

Furthermore, I would guess that he or she would be among the most emotionally stable of our friends and colleagues. I would also make this wager for the ancient inhabitants of Africa, Asia, India or the Americas, of perhaps 2,000 to 6,000 years ago,” Professor Crabtree says.

The basis for my wager comes from new developments in genetics, anthropology, and neurobiology that make a clear prediction that our intellectual and emotional abilities are genetically surprisingly fragile,” he says.

A comparison of the genomes of parents and children has revealed that on average there are between 25 and 65 new mutations occurring in the DNA of each generation. Professor Crabtree says that this analysis predicts about 5,000 new mutations in the past 120 generations, which covers a span of about 3,000 years.

Some of these mutations, he suggests, will occur within the 2,000 to 5,000 genes that are involved in human intellectual ability, for instance by building and mapping the billions of nerve cells of the brain or producing the dozens of chemical neurotransmitters that control the junctions between these brain cells.

Life as a hunter-gatherer was probably more intellectually demanding than widely supposed, he says. “A hunter-gatherer who did not correctly conceive a solution to providing food or shelter probably died, along with his or her progeny, whereas a modern Wall Street executive that made a similar conceptual mistake would receive a substantial bonus and be a more attractive mate,” Professor Crabtree says.

However, other scientists remain sceptical. “At first sight this is a classic case of Arts Faculty science. Never mind the hypothesis, give me the data, and there aren’t any,” said Professor Steve Jones, a geneticist at University College London.

I could just as well argue that mutations have reduced our aggression, our depression and our penis length but no journal would publish that. Why do they publish this?” Professor Jones said.

I am an advocate of Gradgrind science – facts, facts and more facts; but we need ideas too, and this is an ideas paper although I have no idea how the idea could be tested,” he said.

THE DESCENT OF MAN

Hunter-gatherer man

The human brain and its immense capacity for knowledge evolved during this long period of prehistory when we battled against the elements

Athenian man

The invention of agriculture less than 10,000 years ago and the subsequent rise of cities such as Athens relaxed the intensive natural selection of our “intelligence genes”.

Couch-potato man

As genetic mutations increase over future generations, are we doomed to watching  soap-opera repeats without knowing how to use the TV remote control?


1 comment:

  1. This is a brilliant theory. I see but two minor flaws. 1. There is no ...you know ... like evidence. Never mind actua evidence, there is not even any ...like evidence.

    2. The theory makes no actual measurable predictions. That is, the theory is not falsifiable. Which means that it is not really a scientific theory. More a theory like intelligent design is a theory.

    Other than that, it is great.

    ReplyDelete