In 2010, a group of scientists claimed to have found bacteria that could build its DNA using arsenic, instead of the phosphorous used by the rest of Earth's life forms. Within days, the research behind "arsenic life" was under serious scrutiny and we now know that it was totally wrong. But the work was peer-reviewed. It was sponsored by NASA. How do so many experts make such a big mistake?
Dan Vergano at USA Today has an excellent article looking at just that — and it includes the peer review comments that helped the arsenic life paper get published. Though normally secret, Vergano got a hold of them through a Freedom of Information Act request. — Maggie
Remember arsenic life? In 2010 NASA researchers thought they'd found evidence that certain bacteria could use arsenic in their DNA where all other forms of life on Earth use phosphate. Then it turned out their research was really flawed. Then it turned out they were wrong. In general, there was a to-do.
Fast forward to this month, when scientists from the Weizmann Institute of Science in Rehovot, Israel published a study in which they were trying to figure out how bacteria can tell the difference between phosphate and arsenate and "know" to prefer the phosphate. They used phosphate-collecting proteins from four different species of bacteria in their research, including the one that had been at the center of the arsenic life controversy. And along the way, they discovered a fun twist to that story.
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From a public perspective, biology in the oceans, like biology on the land, tends to favor the charismatic megafauna. Stop by your local aquarium and you’ll find masses huddled around the seal pool or the shark tank.
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Remember how scientists discovered alien-esque life forms in California and the Internet was all, "Oh, sheeeet!" But then other scientists started critiquing the research and there was a giant debate about whether one scientist could call out another scientist for bad data on a blog, rather than in a peer-reviewed journal, except that the peer reviewed critiques basically said the same thing and the "discovery" turned out to be totally incorrect? I'm making light of arsenic life here just a bit, but this story of de-discovery continues to be interesting and important. Today, on NPR's Science Friday, science journalist extraordinaire Carl Zimmer will explain why, and will talk about what happens when scientists are wrong
. — Maggie
I love it when news lines up almost perfectly with our editorial calendar. Next week, I've got a Science Question from a Toddler feature lined up that will explain how scientists can date reserves of water, and what makes ancient water special.
This week, in Antarctica, a team of Russian scientists made contact with some very ancient water. Yesterday, they drilled through the last of a more than 12,000-foot ice cover and into Lake Vostok, a reserve of liquid water that hasn't had contact with the outside world in 15-34 million years.
These researchers are looking for extremophile bacteria—semi-alien Earthlings that have evolved separately from the rest of their terrestrial kin. Bryan Walsh at Time.com explains:
The hope is that some form of new microbial life might exist within the waters of the lake, which remain liquid despite the cold thanks to heat generated by the pressure of all that ice and geothermal energy rising from the planet’s core. The environment of Lake Vostok is similar to that found on Jupiter’s icy moon of Europa. If life can survive in Lake Vostok, it might just be able to survive on another planetary body.
It’s still going to take the Russian scientists some time to actually take samples from the lake—with the Antarctic winter on its way, they’ll need to leave Vostok Station soon. And there are environmental concerns that the drilling process could contaminate the lake, which is pristine. The researchers used more than 66 tons (60 metric tons) of lubricants and antifreeze in the drilling process—chemicals that would have polluted Lake Vostok had they leaked through the ice, and contaminated any samples. The good news is that contamination seems to have been avoided: the scientists plugged the bottom of the bore hole with Freon, an inert fluid, and drilled the final distance to the lake surface using a heated drill tip instead of a motorized drill that needed chemical lubricants. When the lake was breached, water flowed up the bore hole before freezing and forming an icy plug.
Researchers at the Universidad de Buenos Aires recreated conditions found on the surface of Jupiter's moon Europa in the lab, and then proved that some Earth organisms are capable of surviving in that extreme environment. At least, for three hours.
It's one experiment in a growing body of work aimed at proving that Earth could seed other planets with life. — Maggie