Isegoria

From Scientist’s Study Of Brain Genes Sparks a Backlash:

Dr. Lahn’s group zeroed in on the role of two genes, called ASPM and microcephalin, that are known to have a role in brain size. Humans with defective copies of either gene are born with brains only about one-third the normal size.

Studying DNA from several species, the Chicago team found that, over millions of years, the genes had undergone more rapid change in monkeys, apes and humans than in other animals. Their next step was to determine if evolution had continued in modern humans. Dr. Lahn’s graduate students began decoding DNA from 1,184 people belonging to 59 groups from around the world, including Bedouins, Pima Indians and French-speaking Basques.

The data showed that evolution had continued in recent millennia. A statistical analysis of DNA patterns suggested that new mutations in each of the two brain-related genes had spread quickly through some human populations. Evidently, these mutations were advantageous among those populations — just as the genetic variant promoting milk digestion was advantageous to early Europeans. Dr. Lahn and his team further observed that the new mutations are found most frequently outside of Africa.

What the data didn’t say was how the mutations were advantageous. Perhaps the genes play a role outside of the brain or affect a brain function that has nothing to do with intelligence.

While acknowledging that the evidence doesn’t permit a firm conclusion, Dr. Lahn favors the idea that the advantage conferred by the mutations was a bigger and smarter brain. He found ways to suggest that in his papers. One mutation, which according to his estimates arose some 40,000 years ago, coincided with the first art found in caves, the paper observed. The other mutation, present mostly in people from the Middle East and Europe, and estimated to be 5,800 years old, coincided with the “development of cities and written language.”

That suggested brain evolution might have occurred in tandem with important cultural changes. Yet because neither variant is common in sub-Saharan Africa, there was another potential implication: Some groups had been left out.

As the article notes, “Dr. Lahn stands by his work but says that because of the controversy he is moving into other projects.”

The march of technology describes the technology of the modern infantry soldier:

A survey of American soldiers — the first conducted in 40 years — found that an infantryman typically carries around 120 pounds, or 55kg, on his back. “If I were to put 120 pounds of kit on you with a weapons system, and then tell you, ‘Okay, now I am going to shoot at you, and you’re going to shoot these targets,’ you would understand how truly difficult it is not only to accomplish your mission, but to just stay alive,” says Jean-Louis “Dutch” DeGay of the American army’s Future Force Warrior (FFW) programme, a $250m effort to devise military technologies for deployment starting in 2010.

The soldier of the future will be wearing three layers:

Closest to the skin will be a layer of clothing, embedded with sensors that can detect whether the wearer is injured, dehydrated, exhausted or even asleep. In the event of injury, vital signs can be measured to assess the soldier’s medical condition, and this information, plus the soldier’s exact location, can be transmitted to a medical team, so that it knows what to expect and can act quickly when it arrives.

The second layer consists of “electro-textiles” that provide power and data connections to these sensors, and to the various other devices being carried by the soldier. Radio antennae can also be incorporated into this layer. Finally, the third and topmost layer consists of a new kind of armour. Existing armour stops bullets, says Mr DeGay, but it is heavy, and its snug fit means that the impact of a bullet can still cause broken bones or internal injuries. The new armour, which will be battle-tested this summer, is based upon flexible Kevlar plates positioned a few centimetres above the skin. This means the plates are better able to absorb and distribute the impact of an incoming round — and also makes the uniform cooler to wear.

A large buildup of strain in the San Andreas fault makes a quake imminent:

Fialko gathered eight years’ worth of radar data from European Space Agency satellites that measure in detail how the ground moves. He also added 20 years’ worth of data from global-positioning measurements on the ground.

Taken together, he says, the measurements suggest that the two plates either side of the southern San Andreas are slipping past each other at around 25 millimetres per year. Without a recent earthquake to alleviate that strain, Fialko says, the fault line itself, which has remained essentially static for centuries, has built up between 5.5 and 7 metres of ‘slip deficit’.

If released all at once, that could result in a magnitude-8.0 earthquake, he says, roughly the size of the devastating 1906 quake in San Francisco. Such a powerful event might threaten even those buildings constructed to earthquake specifications.