Life quite possibly existed before Earth, claim scientists

origins+of+life

Life existed long before Earth came into being, and may have originated outside our solar system, scientists claim.

Researchers say life first appeared about 10 billion years ago – long before Earth, which is believed to be 4.5 billion years old. Geneticists have applied Moore’s Law – observation that computers increase exponentially in complexity, at a rate of about double the transistors per integrated circuit every two years – to the rate at which life on Earth grows in complexity.

Alexei Sharov of the National Institute on Ageing in Baltimore, and Richard Gordon of the Gulf Specimen Marine Laboratory in Florida, replaced the transistors with nucleotides – the building blocks of DNA and RNA – and the circuits with genetic material. Their findings suggest life first appeared about 10 billion years ago, far older than the Earth’s projected age of 4.5 billion years. Like in the 2012 sci-fi movie Prometheus, as our solar system was forming, pre-existing bacteria-like organisms, or even simple nucleotides from an older part of the galaxy, could have reached Earth by hitching an interstellar ride on comets, asteroids or other inorganic space debris.

However, the calculations are not a scientific proof that life predates Earth – there’s no way of knowing for sure that organic complexity increased at a steady rate at any point in the universe’s history.

“There are lots of hypothetical elements to (our argument) … But to make a wider view, you need some hypothetical elements,” Sharov said.

Sharov said that if he had to bet on it, he’d say “it’s 99 per cent true that life started before Earth – but we should leave one per cent for some wild chance that we haven’t accounted for.”

The theory of “life before Earth,” if found true, challenges the long-held science-fiction trope of the scientifically advanced alien species. If genetic complexity progresses at a steady rate, then the social and scientific development of any other alien life form in the Milky Way galaxy would be roughly equivalent to those of humans, the report said.

“Contamination with bacterial spores from space appears the most plausible hypothesis that explains the early appearance of life on Earth,” researchers said.

http://www.phenomenica.com/2013/04/life-did-exist-before-earth-claim-scientists.html

Changes in the anterior insula of hte brain may make us more trusting as we age

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Despite long experience with the ways of the world, older people are especially vulnerable to fraud. According to the Federal Trade Commission (FTC), up to 80% of scam victims are over 65. One explanation may lie in a brain region that serves as a built-in crook detector. Called the anterior insula, this structure—which fires up in response to the face of an unsavory character—is less active in older people, possibly making them less cagey than younger folks, a new study finds.

Both FTC and the Federal Bureau of Investigation have found that older people are easy marks due in part to their tendency to accentuate the positive. According to social neuroscientist Shelley Taylor of the University of California, Los Angeles, research backs up the idea that older people can put a positive spin on things—emotionally charged pictures, for example, and playing virtual games in which they risk the loss of money. “Older people are good at regulating their emotions, seeing things in a positive light, and not overreacting to everyday problems,” she says. But this trait may make them less wary.

To see if older people really are less able to spot a shyster, Taylor and colleagues showed photos of faces considered trustworthy, neutral, or untrustworthy to a group of 119 older adults (ages 55 to 84) and 24 younger adults (ages 20 to 42). Signs of untrustworthiness include averted eyes; an insincere smile that doesn’t reach the eyes; a smug, smirky mouth; and a backward tilt to the head. The participants were asked to rate each face on a scale from -3 (very untrustworthy) to 3 (very trustworthy).

In the study, appearing in the Proceedings of the National Academy of Sciences, the “untrustworthy” faces were perceived as significantly more trustworthy by the older subjects than by the younger ones. The researchers then performed the same test on a different set of volunteers, this time imaging their brains during the process, to look for differences in brain activity between the age groups. In the younger subjects, when asked to judge whether the faces were trustworthy, the anterior insula became active; the activity increased at the sight of an untrustworthy face. The older people, however, showed little or no activation.

Taylor explains that the insula’s job is to collect information not about others but about one’s own body—sensing feelings, including “gut instincts”—and present that information to the rest of the brain. “It’s a warning bell that doesn’t seem to work as well in older people.” By habitually seeing the world in a positive light, older people may be overriding this warning signal, she says. “It looks like the brain is conspiring with what older people do naturally.”

Whether the insula activates in response to non-facial cues, such as telephone scams (a particular problem for older people), remains unclear, says Taylor, since the study was limited to faces.

The new study is the first to show a characteristic pattern of brain activation in a “social” situation involving the assessment of another person’s trustworthiness, says psychologist Lisbeth Nielsen of the National Institute on Aging (NIA) in Bethesda, Maryland. (Though NIA funded the project, Nielsen was not involved in the study.)

A question to be addressed in future research, she says, is whether decreased activity in the insula is the cause or the effect of older peoples’ more positive outlook. “It may be that older people engage with the world in a certain way and this is reflected in the brain activity.”

If so, she adds, older people could work on becoming more cautious. For example, they could be taught to look out for the facial signs of untrustworthiness. “Just because the insula isn’t being activated doesn’t mean it can’t be.”

http://news.sciencemag.org/sciencenow/2012/12/why-old-people-get-scammed.html?ref=hp