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Flower at King's Canyon, by Ed Yong

By this time of the year, we are drowning  in Best Of 2013 lists, featuring the most important events and discoveries of the year. I like to take a different tack here: I’ve deliberately strayed away from things that made other lists, like those from Wired, Nature, Scientific American, Science and, yes, National Geographic. There will be no Voyager, dark matter, olinguitos, BRAIN Initiative, or H7N9. For the same reason, and with sadness, I’m also omitting a few topics that I covered including the oldest hominin DNA ever sequenced, and lab-grown model brains.

Instead, this is a list of my favourite stories, compiled for no other reason that I loved learning and writing about them. It’s a list of unexpected finds and underappreciated progress. Enjoy.

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Credit: Malcolm Burrows

“The image above is an extreme close-up of a common British insect called a planthopper. You’re looking at it from below, at the point where its two hind legs connect to its body. In the middle, you can clearly see that the top of each leg has a row of small teeth, which interlock together. As the planthopper jumps, the teeth ensure that its legs rotate together and extend at the same time.

This insect has gears.

GEARS!

It’s a steampunk bug!”

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Cow by Daniel Schwen; Horned viper by Mircea Nita

“In the cow genome, one particular piece of DNA, known as BovB, has run amok. It’s there in its thousands. Around a quarter of a cow’s DNA is made of BovB sequences or their descendants. If you draw BovB’s family tree, it looks like you’ve entered a bizarre parallel universe where cows are more closely related to snakes than to elephants, and where one gecko is more closely related to horses than to other lizards… This jumping gene not only hops around genomes, but between them.”

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Greater flamingos. Credit: Martin Mecnarowski (http://www.photomecan.eu/)

“It’s a sinister twist on animal gatherings: Rather than finding safety in numbers, the shrimp are being collectively herded towards death’s door by unseen forces.”

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Credit: Dr Graham Beards

“Animal mucus — whether from humans, fish or corals — is loaded with bacteria-killing viruses called phages. These protect their hosts from infection by destroying incoming bacteria. In return, the phages are exposed to a steady torrent of microbes in which to reproduce. “It’s a unique form of symbiosis, between animals and viruses.”

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A bumblebee visits a flower Credit: P7r7, via Wikipedia

Dominic Clarke and Heather Whitney from the University of Bristol have shown that bumblebees can sense the electric field that surrounds a flower. They can even learn to distinguish between fields produced by different floral shapes, or use them to work out whether a flower has been recently visited by other bees. Flowers aren’t just visual spectacles and smelly beacons. They’re also electric billboards.”

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Ring-tailed mongoose. Credit: Ettore Balocchi

“This is one the most extraordinary and convoluted evolutionary tales that I have ever heard. It’s the origin story of a group of viruses called REVs. It’s the tale of how naturalists and scientists inadvertently created a bird virus out of a mammalian one through zoo-collecting and medical research.” It involves a turkey, a pheasant, vaccines, a vanishing malaria parasite, and a mongoose.

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Credit: U.S. Department of Energy Human Genome Program. Credit: U.S. Department of Energy Human Genome Program.

“Women are born with two copies of the X chromosome, while men have just one. This double dose of X-linked genes might cause problems, so women inactivate one copy of X in each cell [using] a gene called XIST (pronounced “exist”). Jun Jiang from the University of Massachusetts Medical School has [now] used XIST to shut down chromosome 21. “Most genetic diseases are caused by one gene, and gene therapies correct that gene,” says Jeanne Lawrence, who led the study. “In this case, we show that you can manipulate one gene and correct hundreds.” It’s chromosome therapy, rather than gene therapy.”

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Dung beetle, by Eric Warrant.

“From all across the galaxy, the light of billions of stars finds its way to Earth, passes through our atmosphere, and enters the eyes of a small South African beetle rolling a ball of dung. The beetle’s eyes are not sensitive enough to pick out individual stars but it can see the Milky Way as a fuzzy stripe, streaking across the night sky. With two of its four eyes, it gazes into the guts of our galaxy, and uses starlight to find its way home.”

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Pandoravirus infecting a cell. Credit: IGS CNRS-AMU)

“The organism was initially called NLF, for “new life form”. Jean-Michel Claverie and Chantal Abergel, evolutionary biologists at Aix-Marseille University in France, found it in a water sample collected off the coast of Chile, where it seemed to be infecting and killing amoebae. Under a microscope, it appeared as a large, dark spot, about the size of a small bacterial cell. Later, after the researchers discovered a similar organism in a pond in Australia, they realized that both are viruses — the largest yet found.”

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Screengrab from video by “Video provided by Klemens Gann and The Thresher Shark Research and Conservation Project. Thresher shark hunting sardines. Screengrab from video by "Video provided by Klemens Gann and The Thresher Shark Research and Conservation Project.

“When I first read about thresher sharks as a kid, I imaged that they would swim towards its prey, bank sharply, and lash out sideways with their tails. Instead, here’s what usually happens. The thresher accelerates towards a ball of fish and brakes sharply by twisting its large pectoral fins. It lowers its snout, pitches its whole body forward, and flexes the base of its tail. This slings the tail tip over its head like a trebuchet, with an average speed of 30 miles per hour.”

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Credit; Johanna Weminghausen Siphonopteron Species 1. Credit; Johanna Weminghausen

“Every individual is a hermaphrodite with both male and female genitals. When they have sex, they can simultaneously penetrate each other, with penises that extend to their whole body length. The penises are also forked. [One] branch ends in a fiendish spine called the penile stylet. It stabs straight into the partner’s forehead, and pumps fluid from the prostate gland.”

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Nervous systems of Alalcomenaeus (top) and a larval horseshoe crab (bottom). Credit: Nick Strausfeld. Nervous systems of Alalcomenaeus (top) and a larval horseshoe crab (bottom). Credit: Nick Strausfeld.

“Here’s (a concise history of) what happened since a little creature called Alalcomenaeus died: Its body sinks to the ocean floor, gets covered in sediment and slowly turns into a stony fossil. Meanwhile, all the world’s land has time to glom together into a mega-continent called Pangaea before breaking up again. Life, was restricted to the oceans, invades the land. Plants and fungi go first, producing thin coverings of mosses and lichens and eventually giant forests. The insects appear, and take to the skies. Other marine animals evolve familiar traits like bones and jaws, and their descendants diversify across the land. Dinosaurs come, see and conquer, before (mostly) dying out. Mammals get their day and one of them, armed with technology and knowledge, unearths Alalcomenaeus from its ancient resting place in what is now China.

As I said: a vastly, hugely, mind-boggling big span of time. Lots happened. And through all of it, the nervous system of this buried animal remained intact.”

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A hypocretin molecule. Credit: Boghog2 A hypocretin molecule. Credit: Boghog2

“On one hand, [the cause of narcolepsy] seems straightforward: people slowly lose a special group of neurons that produce hypocretin, a hormone that keeps us awake. But what kills the neurons? There’s been a lot of evidence to support the idea [that the immune system is responsible] but a team of scientists from Stanford University have finally found what they describe as a “smoking gun”. People with narcolepsy, and only people with narcolepsy, have a special group of immune cells that targets hypocretin. The study also helps to explain some puzzling quirks about narcolepsy, like why the 2009 swine flu pandemic led to a surge of cases in China, or why one particular vaccine against that strain did the same in Europe.”

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Citrus mealybug. Credit: Alexander Wild. Citrus mealybug. Credit: Alexander Wild.

The citrus mealybug looks like a walking dandruff flake, or perhaps a woodlouse that’s been rolled in flour. It’s also the insect version of a Russian nesting doll. If you look inside its cells, you’ll find a bacterium called Tremblaya princeps. And if you look inside Tremblaya, you’ll find yet another bacterium called Moranella endobia. As if this wasn’t complicated enough, some of these machines are built using genetic instructions that are loaned from three other groups of bacteria. So, six different branches on the tree of life have come together to allow this three-way partnership to make the nutrients they need!”

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Micrograph by Robert M. Brucker

“Mountain ranges and rivers can act as physical barriers that separate closely related species and keep them from cross-breeding. But the trillions of microbes in an animal’s guts could have the same role. Robert Brucker and Seth Bordenstein, biologists at Vanderbilt University in Nashville, Tennessee, have found that the gut bacteria of two recently diverged wasp species act as a living barrier that stops their evolutionary paths from reuniting. The wasps have subtly different collections of gut microbes, and when they cross-breed, the hybrids develop a distorted microbiome that causes their untimely deaths.”

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Credit: Fritz Geller-Grimm Credit: Fritz Geller-Grimm

“Sick of being caught on the backfoot [by new epidemics], one team of scientists is spearheading a new approach to dealing with emerging diseases. The researchers want to catalog every single mammalian virus in the world, before they have a chance to spread to humans. Daszak’s team began by counting all the viruses in a single species, the Indian flying fox. Then, they extrapolated to include all 5,500 mammals, estimating that these animals harbor at least 320,000 viruses waiting to be discovered… “In my lifetime, we might be able to find every mammalian virus that might infect us,” said Daszak. “And once you know your enemies, you can start to do something about them.”

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Credit: HJ Media Studios Credit: HJ Media Studios

“Psychologists have been sailing through some pretty troubled waters of late. Critics, many of whom are psychologists themselves, say that these lines of evidence point towards a “replicability crisis”, where an unknown proportion of the field’s results simply aren’t true. To address these concerns, a team of scientists from 36 different labs joined together, like some sort of verification Voltron, to replicate 13 experiments from past psychological studies. They chose experiments that were simple and quick to do, and merged them into a single online package that volunteers could finish in just 15 minutes. This is Big Replication—scientific self-correction on a massive scale.”

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Credit: Sirsnapsalot Image by Sirsnapsalot

“‘Doctors assume that after clinical death, the brain is dead and inactive,’ says Jimo Borjigin. “They use the term ‘unconscious’ again and again. But death is a process. It’s not a black-or-white line.” In a new study, Borjigin discovered that rats show an unexpected pattern of brain activity immediately after cardiac arrest. With neither breath nor heartbeats, these rodents were clinically dead but for at least 30 seconds, their brains showed several signals of conscious thought, and strong signals to boot. This suggests that our final journey into permanent unconsciousness may actually involve a brief state of heightened consciousness.”

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Credit: Jane Hurd Credit: Jane Hurd

“Two teams of scientists showed that three cancer treatments rely on gut bacteria to mobilise the immune system and kill tumour cells—not just in the gut, but also in the blood (lymphomas) and skin (melanomas). Remove the bacteria with antibiotics, and you also neuter the drugs.”

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Credit: Gin Fizz, via Flickr. Credit: Gin Fizz, via Flickr.

“Yoshiaki Yamaguchi and Toru Suzuki have engineered mice that are, with apologies for the awful word, unjetlaggable. If you change the light in their cages to mimic an 8-hour time difference, they readjust almost immediately. Put them on a red-eye flight from San Francisco to London and they’d be fine.”