Sex with time-travellers might kill you.

When time travel finally becomes possible, we might want to think twice about getting it on. According to a new study on tiny shrimp (Artemia franciscana), sex with partners from a different time could kill you.

Researchers at the Center for Functional and Evolutionary Ecology (CEFE) in Montpellier, France, collected preserved brine shrimp eggs from various generations, and then reanimated them with water. Nicolas Rode and colleagues mated pairs of brine shrimp that had been reanimated from eggs preserved since 1985, 1996 and 2007, a period representing roughly 160 generations. They found that females that mated with males from the past or future died off sooner than those that mated with their own generation. The longer the time-shift, the earlier they died: The 22-year time difference shortened female lifetimes by 12 percent; the effect was 3 percent for the 11-year time-shift.

Interestingly, this didn’t affect the females’ reproductive success. Those that lived shorter lives produced the same average number of offspring, they just did it at a faster pace. “Females’ life histories are complex and are constantly adjusted,” explains study co-author Thomas Lenormand. These adjustments reflect the trade-offs between survival and reproduction in nature.

Brine shrimp are part of an interesting class of animal whose eggs can survive decades of drought in a form of dormancy known as cryptobiosis. Once the eggs are reintroduced to water—either in nature or in the lab—they hatch. The species therefore makes an ideal subject for a time-traveling experiment like this one.

What makes time-shifting sex hazardous to health is something called antagonistic coevolution, a way that different species (parasites and hosts, for example) or members of the same species (males and females) adapt to each other to promote their own individual reproductive interests. In nature’s sex wars, males campaign for more offspring—the proverbial seed-spreading—while females play hard-to-get because they bear most of the burden of reproduction and parenthood.

Evolutionary biologists say these conflicts are common in nature, and could occur either as an arms race, with each side’s weapons getting bigger and better, or as a fluctuation, where the two sides take turns dominating each other over time with novel adaptations.

If males and females coevolve their sex organs in tandem, mating with a partner from a different time could leave you unprepared—sort of like heading into modern war with 17th-century armor. The brine shrimp experiment shows just this.

Unfortunately, the researchers couldn’t determine whether there were arms-race-style or fluctuation-style adaptations at work in this experiment. They’d need a longer time-shift to figure that out, which would test the limits of brine shrimp cryptobiosis. They also don’t know what traits made the time-shifting males more deadly. Lenormand and Rode say they’d like to investigate these traits in the future. It could have something to do with amplexus, in which male brine shrimp grasp their partners for hours or even days after sex to keep them from mating with others. A byproduct of this so-called mate guarding is that the females can’t feed, which could shorten their lifetimes. The researchers would also like to flip the experiment on its head, studying the effects of time-shifting sex on males instead of females.

So what does shrimp sex have to do with us? Sexual conflicts and antagonistic coevolution are “probably central to understanding male/female behavior,” Lenormand says. In fact, it turns out that antagonistic coevolution is hard at work in humans today. I’ve previously written about the possible antidepressant properties of seminal fluid. But there’s a dark side to semen, too. Gordon Gallup, an evolutionary biologist as SUNY Albany explained it thus:

“At the level of semen chemistry and vaginal chemistry, there’s competition. The vagina is a very hostile environment for sperm. When a female is inseminated, the presence of the semen triggers an immune reaction, so semen—and particularly the sperm—are treated as pathogens. Male seminal plasma contains all kinds of chemicals that are designed to take this into account. Seminal plasma is alkaline, and a couple seconds after ejaculation the pH of the vagina approaches neutrality, which makes it a friendly environment for sperm. Sperm also contains a lot of immunosuppressants that suppress the female’s immune system and counteract this immune reaction to semen.”

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The largest black hole ever measured

A universal heavyweight champion was crowned this morning at the 217th meeting of the American Astronomical Society in Seattle: A giant black hole weighing a staggering 6.6 billion suns accepted the title of the most massive black hole for which a precise mass has been determined.

That’s not to say it’s necessarily the largest black hole in the universe by any means, but we haven’t measured a bigger one. Located at the heart of the galaxy M87 some 50 million light years away in the direction of Virgo, the black hole is so big it could swallow our solar system hole easily. Its event horizon – the boundary at which nothing, not even light, can escape the monster’s gravitational pull – is four times as large as the orbit of Neptune, our sun’s outermost planetary satellite.

Previous estimates of M87’s black hole mass registered at some 3 billion suns, still 1,000 times the size of the Milky Way’s welterweight black hole. The new measurements were acquired using the adaptive optics capabilities on the 26.6-foot Frederick C. Gillett Gemini Telescope on Mauna Kea, Hawaii, which can compensate for the distorting effects of Earth’s atmosphere. This allowed astronomers to gauge just how fast the stars in M87 are orbiting the black hole, and from that they could determine the mass.

If one simply compares the old measurements of M87’s black hole to it’s current massive size, it might beg the question: Is M87 juicing? Indeed, astronomers think the black hole did get some outside help beefing up over the course of its lifetime. Aside from feasting on gas and stars, M87’s champion is likely the result of a series of black hole mergers, the last of which may have happened in the not too distant past.

Whether M87’s black hole achieved its mass fairly or not, it may not hold the heavyweight title for very long anyhow. Over the next decade astronomers plan to hook up telescopes all over the world to create a whole Earth submillimeter array that will vastly increase their ability to locate event horizons and characterize the size of black holes throughout the universe.

 

Beam me up, Scotty!

Using only light, Australian researchers say they are able to move small particles almost five feet through the air. It’s more than 100 times the distance achieved by existing optical “tweezers,” the researchers say.

Not quite a simple grabby tractor beam, the new system works by shining a hollow laser beam at an object and taking advantage of air-temperature differences to move it around.

Moving objects with powerful light is not new — researchers have long been using optical tweezers to pluck bacteria-sized particles and move them a few millimeters. The U.S. Secretary of Energy, Steven Chu, won his Nobel Prize for work with optical tweezers. But Andrei Rhode and colleagues at the Australian National University say their new laser device can move glass objects hundreds of times bigger than bacteria, and shove them a meter and a half (5 feet) or more. Rhode says the 1.5-meter limit was only because of the size of the table where he placed his lasers — he thinks he can move objects up to 10 meters, or about 30 feet.

It works by shining a hollow laser beam around small glass particles, as Inside Science explains. The air around the particle heats up, but the hollow center of the beam stays cool. The heated air molecules keep the object balanced in the dark center. But a small amount of light sneaks into the hollow, warming the air on one side of the object and nudging it along the length of the laser beam. Researchers can change the speed and direction of the glass object by changing the lasers’ brightness.

The system needs heated air or gas to work, so in its present incarnation it wouldn’t work in space — sorry, Star Wars fans. But it could be used for a variety of purposes on Earth, like biological research or movement of hazardous materials.

The Titans are coming.

In a simulation, a Titan-like atmosphere produces nearly all of life’s building blocks.

Scientists studying Titan’s atmosphere have learned it can create complex molecules, including amino acids and nucleotide bases, often called the building blocks of life. They are the first researchers to show it’s possible to create these molecules without water, suggesting Titan could harbor huge quantities of life’s precursors floating in its atmosphere. It’s a breakthrough that even has implications for the beginning of life on Earth.

Researchers at the University of Arizona built a simulated Titan atmosphere in a special chamber in Paris and blasted it with microwaves, simulating the effect of solar energy. The reactions produced aerosols, which sank to the bottom of the chamber, where scientists scooped them up for study. What they found was unexpected, to put it mildly: all the nucleotide bases that make up the genetic code of all life on Earth, and more than half of the 22 amino acids that make proteins.

Of course, this doesn’t prove Titan has life — this was a test chamber, not the actual moon’s atmosphere, for one thing — but it’s intriguing, at least.

“Our results show that it is possible to make very complex molecules in the outer parts of an atmosphere,” said Sarah Hörst, a graduate student in the University of Arizona’s Lunar and Planetary Lab, in a UA News story. She led the research effort with her adviser, planetary science professor Roger Yelle.

Titan is one of the most promising places for life elsewhere in the solar system. It has huge methane lakes and scientists recently learned that hydrogen is disappearing faster than it should at the surface, suggesting some sort of chemical reaction is consuming it.

The best data about Titan’s characteristics has come from the spacecraft Cassini, which has tasted some of the moon’s outermost atmosphere in a series of flybys since 2004. But Cassini was not designed to dip below 560 miles above the surface, much too far to really get a sense of what the moon’s atmosphere contains.

To truly test its capabilities, researchers would have to recreate the atmosphere in a lab, mixing the gases found on TItan and subjecting them to radiation. The microwaves caused a gas discharge, the same process that makes neon signs glow, which caused some of the nitrogen, methane and carbon monoxide to bond together into solid matter. These aerosols were levitated in a special chamber before they got heavy enough to fall down. The prospect of small floating life forms in the Titanic atmosphere is intriguing enough, but the study also revealed some interesting possibilities about the genesis of life on Earth. Titan’s atmosphere might be chemically similar to that of the early Earth, suggesting that instead of emerging from a primordial soup, the building blocks of life might have rained down from on high.

Hörst said the most interesting aspect of the study was proof that you can make pretty much anything in an atmosphere — a finding with major implications for astrobiology.

“Who knows this kind of chemistry isn’t happening on planets outside our solar system?” she said.

Trees as streetlights.

Taiwanese researchers have come up with the elegant idea of replacing streetlights with trees, by implanting their leaves with gold nanoparticles. This causes the leaves to give off a red glow, lighting the road for passersby without the need for electric power. This ingenious triple threat of an idea could simultaneously reduce carbon emissions, cut electricity costs and reduce light pollution, without sacrificing the safety that streetlights bring.

As many good things do, this discovery came about by accident when the researchers were trying to create lighting as efficient as LEDs without using the toxic, expensive phosphor powder that LEDs rely on. The gold nanoparticles, shaped like sea urchins, put into the leaves of Bacopa caroliniana plants cause chlorophyll to produce the reddish luminescence.

In an added bonus, the luminescence will cause the leaves’ chloroplasts to photosynthesize, which will result in more carbon being captured from the air while the streets are lit. The next steps are to improve the efficiency of the bioluminescence and apply the technology to other biomolecules.

Mutant mouse tweets like a bird.

A laboratory at the University of Osaka running an ongoing study on evolution has revealed that they’ve produced a genetically engineered mouse that tweets like a bird. They’ve produced more than 100 of them actually, as well as a mouse with short limbs and one with a tail like a dachshund. It’s all part of a larger study into how genetic mutations drive evolutions and diverse outcomes that can come about as a result of miscopying DNA.

The researchers didn’t engineer the mouse to tweet, though there was some genetic tinkering that led to the singing mouse’s arrival. The lab created the mouse as part of its “Evolved Mouse Project,” which genetically modifies mice to be prone to miscopying DNA. From there, the outcomes are left to chance as the team has cross-bred the mutation prone mice for generations.

According to the lead researcher at the lab, they were checking their newborn mice one at a time and one day came across a mouse that was singing just like a bird – a point that is significant beyond being both weird and interesting. Scientists already know that birds don’t sing haphazardly, but in a way that is governed by a set of linguistic rules that form strings of sounds. In other words it’s ordered noise, much like human speech.

The team now hopes their tweeting mice will lend insight on how human language evolved over history. Mice, after all, are much closer to humans in terms of biology and brain, and by seeing how they chirp in the company of other mice and when placed in certain situations, they might learn how human linguistics came to be as well as how they were shared among groups.

Just one of many?

Just when the search for exoplanets looked like the undisputed fashionable field of study for 2010, the cosmic microwave background (CMB) is stepping to the forefront of astronomy and cosmology. Last month, it was Oxford’s Roger Penrose claiming that he’d found evidence of a cyclical universe in patterns of concentric circles in the CMB, suggesting our universe is just one of many that have come before it (and will come after it). Now, another group of researchers are claiming the CMB contains evidence of other universes that exist concurrently (and outside of) our own.

The new evidence, put forth by a group of researchers at University College London, is based upon the model of “eternal inflation,” which is predicated on the idea that our universe is part of a larger and ever-expanding multiverse. Our universe is contained in a kind of cosmic bubble that exists alongside other universes contained in their own bubbles, and in these universes the rules of physics could be far different than in our own.

If the eternal inflation theory is correct, it follows that our universe and other universes have likely collided in the past as they violently bounced around the larger multiverse, and those collisions should be evident in the CMB (the cosmic microwave background is a leftover from the Big Bang, and thus is of interest to astronomers and cosmologists for the long historical record it contains – if researchers know what to look for).

The University College team went looking for “cosmic bruises” in the CMB that indicate places where other universes collided with our own at some point, and it claims to have found them in data from the Wilkinson Microwave Anisotropy Probe
(WMAP), which has been measuring temperature differences in the CMB over the past decade. If indeed the spots are found to be “cosmic bruises,” it would lend a lot of credence to the idea that there are other universes out there that at some point collided with our own.

But that’s a big “if.” If the earlier CMB findings by Penrose are any indicator, proving or disproving these sorts of claims rooted in WMAP data is extremely difficult. Fortunately the ongoing Planck mission should soon provide a much better picture of the CMB to astronomers, allowing them to hopefully prove or disprove some of these cosmological theories. Until then, the time is ripe to attribute statistical anomalies in the vast CMB data set to complex cosmological theories.