Galaxy holds 100M complex-life-supporting planets

Our galaxy may hold 100M complex-life-supporting planets:

Our galaxy may hold 100M complex-life-supporting planets

Our galaxy may hold 100M complex-life-supporting planets

The number of planets in the Milky Way galaxy which could harbor complex life may be as high as 100 million, Washington State University astrobiologist Dirk Schulze-Makuch writes in a column posted this week on the Air & Space/Smithsonian magazine website.

The estimate, which assumes an average of one planet per star in the Milky Way, is drawn from a study believed to be the first quantitative assessment of the number of worlds in our galaxy that could harbor life above the microbial level.

Schulze-Makuch said the study is significant because it is the first to rely on observable data from actual planetary bodies beyond the solar system, rather than making educated guesses about the frequency of life on other worlds based on hypothetical assumptions.

The research was published recently in the journal Challenges by a group of scientists that includes Louis Irwin, of the University of Texas at El Paso; Alberto Fairen of Cornell University; Abel Mendez of the Planetary Habitability Laboratory at the University of Puerto Rico at Arecibo; and Schulze-Makuch.

The researchers surveyed the growing list of more than 1,000 known planets outside the solar system. Using a formula that considers planetary density, temperature, substrate (liquid, solid or gas), chemistry, distance from its central star and age, they computed a “Biological Complexity Index (BCI),” which rates planets on a scale of 0 to 1.0 according to the number and degree of characteristics assumed to be important for supporting various forms of multicellular life.

“The BCI calculation revealed that 1 to 2 percent of exoplanets showed a BCI rating higher than Europa, a moon of Jupiter thought to have a subsurface global ocean which could harbor different forms of life,” writes Schulze-Makuch. “Based on an estimate of 10 billion stars in the Milky Way Galaxy, and assuming an average of one planet per star, this yields the figure of 100 million. Some scientists believe the number could be 10 times higher.”

He emphasizes that the study should not be taken as an indication that complex life actually exists on as many as 100 million planets, but rather that the figure is the best estimate to date of the number of planets in our galaxy likely to exhibit conditions supportive to such life.

“Also, it should be understood that complex life doesn’t mean intelligent life or even animal life, although it doesn’t rule either out,” Schulze-Makuch said. “It means simply that organisms larger and more complex than microbes could exist in a number of different forms, quite likely forming stable food webs like those found in ecosystems on Earth.

“Despite the large absolute number of planets that could harbor complex life, the Milky Way is so vast that, statistically, planets with high BCI values are very far apart,” Schulze-Makuch writes. “One of the closest and most promising extrasolar systems, known as Gliese 581, has possibly two planets with the apparent capacity to host complex biospheres, yet the distance from the Sun to Gliese 581 is about 20 light years.”

And most planets with a high BCI are much farther away, he said.

If the 100 million planets that the team says have the theoretical capacity for hosting complex life were randomly distributed across the galaxy, Schulze-Makuch said they would lie about 24 light years apart, assuming equal stellar density. And he estimates the distance between planets with intelligent life would likely be significantly farther.

“On the one hand it seems highly unlikely that we are alone,” he writes in the article. “On the other hand, we are likely so far away from life at our level of complexity, that a meeting with such alien forms might be improbable for the foreseeable future.”

 

Source:  scienceblog.com

Protein Drug mimic’s food deprivation

A Drug That Can Extend Life as Effectively As Dieting:

A Drug That Can Extend Life as Effectively As Dieting

A Drug That Can Extend Life as Effectively As Dieting

Many studies have shown that rigorous caloric restriction, or strict dieting, can increase longevity dramatically in lifeforms from yeast to humans. But a study released today shows one way to mimic the life-extending effects of food deprivation – using drugs.

A team of researchers in the UK explored the role of a protein known as S6K1, which turns out to play an extraordinary role in aging and age-related disease. When the researchers grew mice lacking the gene to produce S6K1, their mice lived significantly longer (see chart – the red lines are mice without S6K1). They also developed fewer age-related debilitating conditions.

A Drug That Can Extend Life as Effectively As Dieting

Female mice without S6K1 lived slightly longer than their male counterparts, and over 160 days longer than the control group. That means the female mouse lifespan increased by twenty percent.

Mice without S6K1 also lost weight, even if they ate more than ordinary mice. In other words, a substance that could block the expression of S6K1 would trick the body into thinking that you’d gone on a very rigorous diet. And it would make you healthier into an older age. The best part?

In their paper, the researchers conclude:

It might be possible to develop drug treatments that manipulate S6K1 and AMPK to achieve improved overall health in later life. Indeed, short-term rapamycin treatment reduces adiposity in mice, and metformin treatment [often used against type 2 diabetes] extends lifespan in short-lived mice.

This is good news, because often when researchers make discoveries related to longevity there is no immediate pathway to manufacturing a life-extending drug. For all of us who want to stay healthy in old age while still eating sugar and fat once in a while, let’s hope this research team starts testing a drug based on their S6K1 discovery – and soon.

Earth’s evolutionary ancestor is a planet-spanning organism

The ancestor of all life on Earth might have been a gigantic planetary super-organism:

The ancestor of all life on Earth might have been a gigantic planetary super-organism

The ancestor of all life on Earth might have been a gigantic planetary super-organism

All life on Earth is related, which means we all must share a single common evolutionary ancestor. And now it appears that this ancestor might have been a single, planet-spanning organism that lived in a time that predates the development of survival of the fittest. That’s the idea put forward by researchers at the University of Illinois, who believe the last universal common ancestor, or LUCA, was actually a single organism that lived about three billion years ago. This organism was unlike anything we’ve ever seen, and was basically an amorphous conglomeration of cells. Instead of competing for resources and developing into separate lifeforms, cells spent hundreds of millions of years freely exchanging genetic material with each other, which allowed species to obtain the tools to survive without ever having to compete for anything. That’s maybe not an organism as we would comprehend it today, but that’s the closest term we have for this cooperative arrangement. All that we know about LUCA is based on conjecture, and the most promising recent research has been in figuring out what proteins and other structures are shared across all three domains of life: the unicellular bacteria and archaea and the multi-celled eukaryotes, which are where all plants and animals evolved from. This isn’t a foolproof method — it’s possible that two extremely similar but not identical structures could evolve independently after LUCA split into the three domains — but it’s a good starting point. Illinois researcher Gustavo Caetano-Anollés says about five to eleven percent of modern proteins could be traced back to LUCA. Based on the function of these particular proteins, it appears LUCA had the enzymes needed to break down nutrients and get energy from them, and it could also make proteins, but it probably didn’t have the tools necessary to make DNA. This fits with other research that suggests LUCA fed upon many different food sources, and that it had internal structures in its cells known as organelles. The big difference between LUCA and everything that came after, of course, is DNA. Because LUCA didn’t have the tools to deal with DNA, it probably used RNA instead, and it likely had very little control over the proteins that it made. The research suggests the ability to precisely control protein manufacture only came long after LUCA split apart, which means that protein-making was probably always a big crapshoot. That’s why LUCA had to be cooperative, with any cells that produced useful proteins able to pass them on throughout the world without competition. This was a weird variation on what we know as natural selections — helpful proteins could go from a single cell to global distribution, while harmful or useless proteins were quickly weeded out and discarded. The result was the equivalent of a planet-spanning organism. So why did this paradise of cellular cooperation give way to the last three billion years of cutthroat competition? The simple answer is that some cells probably outgrew this arrangement, as they had finally developed all the structures needed to survive without help. We don’t know quite why that happened, but it appears to coincide with the sharp increase of oxygen in the atmosphere. Whatever the cause, cells began eking out their own independent existences, ending the reign of LUCA that had lasted hundreds of millions of years… while beginning a new order that is still going strong 2.9 billion years later.

Apple’s iPhone 5 battery Sucks

IPhone 5 battery issues reported, poor battery life remains Smartphones’ dirty little secret:

 iPhone 5 battery issues reported Seems poor battery life remains smartphones’ dirty little secret.


iPhone 5 battery issues reported
Seems poor battery life remains smartphones’ dirty little secret.

Apple’s claims to have improved the smartphone owner’s perennial problem of disappointing battery life with the iPhone 5 look to be wide of the mark today, amid an outbreak of complaints from chagrined early adopters. With no official response and mixed testimonies online, it’s hard to discern the scale of the problem. However, threads on the Apple support forums, one of which stretches to over 100 replies, more than testify to its existence.

iPhone 5 black bottom half close-up

Among them is Holdrege, who reports that his “iPhone 5 drains way faster than my two-year-old iPhone 4. Meanwhile, DJleviathan attests that although Apple claims the battery will provide “eight hours of constant use” in reality it “ends up only lasting half that time”. One London-based Orange customer who got in touch with us reported that his battery fell from “90 per cent to 10 per cent in eight hours with LTE on”, in which time he claims to have only used the internet to “check the Fulham scores once or twice”. Apple’s marketing copy claims that the iPhone 5’s custom-built A6 processor is so power efficient that the phone lasts twice as long as the iPhone 4S on a single full charge, despite potential battery-punishing features on the new handset such as a larger screen and 4G connectivity. The company is also currently attempting to deflect criticism of the iPhone 5’s Apple Maps mapping solution, which has been found to be riddled with inaccuracies and spelling howlers.