In the Gulf of Mexico, nature’s janitors are hard at work, mopping up the aftermath of a man-made disaster. On 20 April, 2010, an explosion at the Deepwater Horizon rig unleashed the largest oil spill in US history. Now, a team of American scientists led by Terry Hazen have shown that just a month or so after the incident, a microscopic clean-up crew had already started to digest the mess.
The ocean is home to many groups of bacteria that can break down the chemicals found in crude oil. Some, like Alcanivorax, are oil-eating specialists that are usually found in low numbers, only to bloom when oil spills provide them with a sudden banquet. That’s exactly what has happened in the Gulf of Mexico. Hazen has found that these oil-eaters have swelled in number in the contaminated waters.
According to all sorts of “how-to” sites, one of the most important rules for online writing is to keep it short. Well, try telling that to Atul Gawande and his legion of readers. Known for his superb long-form essays and books, Gawande recently published a masterful piece in the New Yorker about death and dying. I plugged the full text into Word and it weighs in at a monstrous 12,000 words. This is a feature that makes Wired articles look like paragraphs.
And yet, its copious length flies by. I read the piece in 20 minutes, with no distractions except for the occasional need to reach for some tissues. I’m not alone in thinking this; the piece was passed all over Twitter, with several people noting how readable it is despite the excessive word count. And bear in mind that all of these people read the piece on screen (and I digested it as a single, scrolling column). How does it succeed?
Tyrone Hayes, a researcher working on the effects of a pesticide on amphibians, has been accused of violating ethical standards because of a series of frankly incredible emails he sent to Syngenta representatives. Nature has the story and the full emails.
You want dinosaurs. Fighty, stabby, bitey dinosaurs. You especially want them written about by Brian Switek in Wired, with pretty pictures.
Batman’s logo became a lot more detailed over the years…
The night sky is the setting for an arms race that has been going on for millions of years: a conflict between bats and moths. Many bats can find their prey by giving off high-pitched squeaks and listening out for the echoes that return. This ability – echolocation – allows them to hunt night-flying insects like moths, which they skilfully pluck out of the air. But moths have developed countermeasures; some have evolved ears that allow them to hear the calls of a hunting bat and take evasive action. And bats, in turn, have adapted to overcome this defence.
Holger Goerlitz from the University of Bristol has found that the barbastelle bat is a stealth killer that specialises in eating moths with ears. Its echolocation calls are 10 to 100 times quieter than those of other moth-hunting bats and these whispers allow it to sneak up on its prey. It’s the latest move in an ongoing evolutionary dogfight and for now, the barbastelle has the upper wing.
Six million years ago, Argentina was ruled by ‘terror birds’. These giant flightless hunters, standing one to three metres tall were at the top of the food chain and killed using a massive, hooked beak, up to two feet in length. The murderous beaks are certainly evocative, but they were no blunt instruments. They were precision weapons, used with finesse and wielded with speed and agility.
Federico Degrange analysed the skull of a medium-sized terror bird called Andalgalornis and found that it was incredibly strong when biting straight down, but far weaker when being shaken from side to side. If the bird tried to subdue a struggling victim, its beak would probably have snapped under the strain. So despite its size, Andalgalornis probably danced around its prey, advancing and retreating while dispatching it with quick, well-aimed strikes – more Muhammad Ali than George Foreman.
If you watch chimpanzees from different parts of Africa, you’ll see them doing very different things. Some use sticks to extract honey from beehives, while others prefer leaves. Some use sticks as hunting spears and others use them to fish for ants. Some drum on branches to get attention and others rip leaves between their teeth.
These behaviours have been described as cultural traditions; they’re the chimp equivalent of the musical styles, fashion trends and social rules of humans. They stem from the readiness of great apes to ape one another and pick up behaviours from their peers. But a new study complicates our understanding of chimp cultures. Kevin Langergraber at the Max Planck Institute for Evolutionary Anthropology has found that much of this variation in behaviour could have a genetic influence.
Flatfish are the closest living relatives to swordfish and marlins
At first glance, a swordfish and a flounder couldn’t seem more different. One is a fast, streamlined hunter with a pointy nose, and the other is an oddly shaped bottom-dweller with one distorted eye on the opposite side of its face. Their bodies are worlds apart, but their genes tell a different story.
Alex Little from Queen’s University, Canada, has found that billfishes, like swordfish and marlin, are some of the closest living relatives to the flatfishes, like plaice, sole, flounder and halibut. This result was completely unexpected; Little was originally trying to clarify the relationship between billfishes and their supposed closest relatives – the tunas. That connection seems to make more sense. Both tunas and billfishes are among a handful of fish that are partially warm-blooded. They can heat specific body parts, such as eyes and swimming muscles, to continuously swim after their prey at extremely fast speeds with keen eyesight.
But it turns out that these similarities are superficial. Little sequenced DNA from three species of billfishes and three tunas, focusing on three parts of their main genome and nine parts of their mitochondrial one (a small accessory genome that all animal cells have). By comparing these sequences to those of other fish, Little found that the billfishes’ closest kin are the flatfish and jacks. Indeed, if you look past the most distinctive features like the long bills and bizarre eyes, the skeletons of these groups share features that tunas lack. Indeed, billfish and tuna proved to be only distant relatives. Their ability to heat themselves must have evolved independently and indeed, their bodies product and retain heat in quite different ways.
Little’s work is testament to the power of natural selection. Even closely related species, like marlins are flounders, can end up looking vastly different if they adapt to diverse lifestyles. And distantly related species like tuna and swordfish can end up looking incredibly similar because they’ve adapted to similar challenges – pursuing fast-swimming prey. This shouldn’t come as a surprise – a few months ago, a French team found that prehistoric predatory sea reptiles were probably also warm-blooded.
Ancient death-grip scars caused by fungus-controlled ants
Forty-eight million years ago, some ants marched up to a leaf and gripped it tight in their jaws. It would be the last thing they would ever do. Their bodies had already been corrupted by a fungus that, over the next few days, fatally erupted from their heads. The fungus produced a long stalk tipped with spores, which eventually blew away, presumably to infect more ants. In time, all that was left of this grisly scene were the scars left by the ants’ death-grip. Today, David Hughes from Harvard University has found such scars in a fossilised leaf from Germany.
Today, hundreds of species of Cordyceps fungi infect a wide variety of insects, including ants. Like many parasites, they can manipulate the way their hosts behave. One species, Cordyceps unilateralis, changes the brains of its ant hosts so that they find and bite into leaves, some 25cm above the forest floor. The temperature and humidity in this zone are just right for the fungus to develop its spore capsules. In its dying act, the ant leaves a distinctive bite mark that’s always on one of the leaf’s veins on its underside. And that’s exactly what Hughes saw in his fossil leaf.
Hughes originally thought that the marks were made by an insect cutting the veins of the leaf to drain away any potential poisons, something that modern insects also do. But these marks look very different – those on the fossil leaf bear a much closer resemblance to those of Cordyceps-infected ants. This is the first fossil trace of a parasite manipulating its host, but it’s not the oldest evidence for such a relationship. In 2008, another American group found a 105-million-year-old piece of amber containing a scale insect, with two Cordyceps stalks sticking out of its head. The war between insects and their Cordyceps nemeses is an ancient one indeed.
There are great plays and bad ones, but the playwright’s actual text is only one aspect of a production. The very same words can take on radically different meanings depending on the whims of the director, the abilities of the actors and the setting of the stage. The same is true of our genes and our environments. In cases where genes affect our behaviour, the same stretch of DNA can lead to very different deeds, depending on individual circumstances. Just as a production defines a play, environments and cultures alter the effects of certain genes.
Heejung Kim from the University of California has discovered a great example of this effect by studying a gene called OXTR (or the ‘oxytocin receptor’, in full). The gene creates a docking station for a hormone called oxytocin, which is involved in all sorts of emotions and social behaviours, from trust to sexual arousal to empathy.
Kim looked at a specific version of the OXTR gene, whose carriers are allegedly more social and sensitive. But this link between gene and behaviour depends on culture; it exists among American people, who tend to look for support in troubled times, but not in Korean cultures, where such support is less socially acceptable. Culture sets the stage on which the OXTR gene expresses itself. (more…)
If you’re trapped in a building, it’s probably not the best time to start setting fire to things. But this is exactly what some bacteria do when they find themselves in a human; they cause diseases that are potentially fatal but not contagious. Without an escape, they risk going down with their host. This seems like a ludicrous strategy but we’re looking at it from the wrong perspective – our own. In truth, humans often have nothing to do with the diseases that plague us; we’re just collateral damage in an invisible war.
Like all living things, bacteria have to defend themselves against predators like amoebas. Some species do so using resistance genes that turn them from passive victims into aggressive fighters. And by coincidence, these same adaptations make them more virulent (good at causing disease) in human bodies. We’re just caught in the crossfire.
These Australian pelicans (Pelecanus conspicillatus) were photographed at Perth Zoo. They provided a pleasant distraction from the fact that a bloomin’ great Icelandic volcano had just erupted and was about to ground me for a week…
Ed Yong is an award-winning British science writer. His work has appeared in New Scientist, the Times, WIRED, the Guardian, Nature and more. Not Exactly Rocket Science is his attempt to talk about the awe-inspiring, beautiful and quirky world of science to as many people as possible.
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In the Gulf of Mexico, nature’s janitors are hard at work, mopping up the aftermath of a man-made disaster. On 20 April, 2010, an explosion at the Deepwater Horizon rig unleashed the largest oil spill in US history. Now, a team of American scientists led by Terry Hazen have shown that just a month or so after the incident, a microscopic clean-up crew had already started to digest the mess. 
