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Alan Kingstone, a psychologist at the University of British Columbia, had a problem: all humans have their eyes in the middle of their faces, and there’s nothing that Kingstone could do about it. His 12-year-old son, Julian Levy, had the solution: monsters. While some monsters are basically humanoid in shape, others have eyes on their hands, tails, tentacles and other unnatural body parts. Perfect. Kingstone would use monsters. And Julian would get his first publication in a journal from the Royal Society, one of the world’s most august scientific institutions.
In 1998, Kingstone showed that people will automatically look where other people are looking. Other scientists have since found this gaze-copying behaviour among many other animals, from birds to goats to dolphins. It seems fairly obvious why we would do this—we get an easy clue about interesting information in the world around us. But what are we actually doing?
There are two competing answers. The obvious one is that we’re naturally drawn to people’s eyes, so we’ll automatically register where they’re looking. Indeed, one part of the brain – the superior temporal sulcus – is involved in processing the direction of gazes. The equally plausible alternative is that we’re focused more broadly on faces, and the eyes just happen to be in the middle. After all, we see faces in inanimate objects, and we have a area in our brains—the fusiform face area (FFA)—that responds to the sight of faces.
One evening, Kingstone was explaining these two hypotheses to Julian over dinner. “A colleague had said that dissociating the two ideas — eyes vs. centre of head — would be impossible because the eyes of humans are in the centre of the head,” Kingstone said. “I told Julian that when people say something is impossible, they sometimes tell you more about themselves than anything.”
Julian agreed. He thought it would be easy to discriminate between the two ideas: just use the Monster Manual. This book will be delightfully familiar to a certain brand of geek. It’s the Bible of fictional beasties that accompanied the popular dice-rolling role-playing game Dungeons and Dragons. Regularly updated, it bursts with great visuals and bizarrely detailed accounts of unnatural history. It has differently coloured dragons, undead, beholders… I think one edition had a were-badger. Parts of this blog are essentially a non-fictional version of the Monster Manual.
In a lab at MIT, a rat enters a T-shaped maze, hears a tone, and runs down the left arm towards a piece of chocolate. It’s a habit. The rat has done the same thing over so many days that once it hears the tone, it’ll run in the same direction even if there’s no chocolate to be found. Humans are driven by similar habits. Every morning, I hear my alarm go off, put some clothes on, and shamble into the kitchen to brew some coffee.
Habits, by their very nature, seem permanent, stable, automatic. But they are not, and the MIT rat tells us why. Earlier, Kyle Smith had added a light-sensitive protein to one small part of its brain – the infralimbic cortex (ILC). This addition allows Smith to silence the neurons in this one area with a flash of yellow light, delivered to the rat’s brain via an optic fibre. The light flashes for just three seconds, and the habit disappears. The rat hears the tone, but no longer heads down the chocolate arm.
The experiment shows that even though habits seem automatic, they still depend on ongoing supervision from the ILC and possibly other parts of the brain. They’re ingrained and durable, but subject to second-by-second control. And they can be disrupted in surprisingly quick and simple ways.
“We were all stunned by how immediate and on-line these effects really are,” says Smith. “Changing the activity of this small cortex area could profoundly change how habitual behaviour was, in a matter of seconds.”
Sometimes, when you have insomnia and you’ve read the entire internet and you idly check your blog stats, something nice pops up. Not Exactly Rocket Science has been with Discover since March 2010, and at some point today, it will hit it 10 millionth page view since being with the site. Hooray! I have the smile of a proud father.
In 1890, the fossil-hunter Othniel Charles Marsh described a new species of dinosaur from Colorado. He only had a foot and part of a hand to go on, but they were so bird-like that Marsh called the beast Ornithomimus – the bird mimic. As the rest of Ornithomimus’ skeleton was later discovered, Marsh’s description seemed more and more apt. It ran on two legs, and had a beaked, toothless mouth. Despite the long tail and grasping arms, it vaguely resembled an ostrich, and it lent its name to an entire family – the ornithomimids—which are colloquially known as “ostrich dinosaurs”.
Now, the bird mimic has become even more bird-like. By analysing two new specimens, and poring over an old famous one, Darla Zelenitsky from the University of Calgary has found evidence that Ornithomimus had feathers. And not just simple filaments, but wings – fans of long feathers splaying from the arms of adults. (More technically, it had “pennibrachia” – a word for wing-like arms that couldn’t be used to glide or fly.)
The thing in the photo above, I’m sad to say, is a penis. It belongs to the male seed beetle. And just in case you’re holding out hope that appearances are deceiving, I can assure you they are not. Those spikes are hard and sharp, and they inflict heavy injuries upon the female beetles during sex. Why would such a hellish organ evolve?
This isn’t just about beetles. The animal kingdom is full of bafflingly-shaped penises adorned with spines, spikes, and convoluted twists and turns. In some animal groups, like certain flies, penis shape is the only clue that allows scientists to distinguish between closely related species.
For a male, sex isn’t just about penetration. After he ejaculates inside a female, his sperm still have to make their way to her eggs to fertilise them and pass on his genes. If she mates with many suitors, her body becomes a battleground where the sperm of different males duke it out. Females can influence this competition by being choosy over mates, storing sperm in special pouches, or evolving their own convoluted genital passages. Males, meanwhile, have evolved their own tricks, including: guarding behaviour; self-castration; barbed sperm; chemical weapons in their sperm; mating plugs; ‘traumatic insemination’; and having lots of sperm.
And spiky penises. That too.
The bay at the Danish port of Aarhus is pretty enough, with the usual fare of beach-goers, holiday homes and yachts. But the bay’s most spectacular residents live in the mud beneath its water. Back in 2010, Lars Peter Nielsen found that this mud courses with electric currents that extend over centimetres. Nielsen suspected that the currents were carried by bacteria that behaved like electric grids. Two years on, it seems he was right. But what he found goes well beyond what even he had imagined.
Nielsen’s student Christian Pfeffer has discovered that the electric mud is teeming with a new type of bacteria, which align themselves into living electrical cables. Each cell is just a millionth of a metre long, but together, they can stretch for centimetres. They even look a bit like the cables in our electronics—long and thin, with an internal bundle of conducting fibres surrounded by an insulating sheath.
Nielsen thinks that each cable can be considered as a single individual, composed of many cells. “To me, it’s obvious that they are multicellular bacteria,” he says. “This was a real surprise. It wasn’t among any of our hypotheses. These distances are a couple of centimetres long—we didn’t imagine there would be one organism spanning the whole gap.”
The bacteria are members of a family called Desulfobulbaceae, but their genes are less than 92 percent identical to any of the group’s known members. “They’re so different that they should probably be considered a new genus,” says Nielsen. They’re only found in oxygen-starved mud, but where they exist, there’s a lot of them. On average, Pfeffer found 40 million cells in a cubic centimetre of sediment, enough to make around 117 metres of living cable.
As animals get bigger, so do their brains. But the human brain is seven times bigger than that of other similarly sized animals. Our close relative, the chimpanzee, has a brain that’s just twice as big as expected for its size. And the gorilla, which can grow to be three times bigger than us, has a smaller brain than we do.
Many scientists ask why our brains have become so big. But Karina Fonseca-Azevedo and Suzana Herculano-Houzel from the Federal University of Rio de Janeiro have turned that question on its head—they want to know why other apes haven’t evolved bigger brains. (Yes, humans are apes; for this piece, I am using “apes” to mean “apes other than us”).
Their argument is simple: brains demand exceptional amounts of energy. Each gram of brain uses up more energy than each gram of body. And bigger brains, which have more neurons, consume more fuel. On their typical diets of raw foods, great apes can’t afford to fuel more neurons than they already have. To do so, they would need to spend an implausible amount of time on foraging and feeding. An ape can’t evolve a brain as big as a human’s, while still eating like an ape. Their energy budget simply wouldn’t balance.