Many mental disorders can disrupt the sweet embrace of a long, continuous sleep, including alcoholism, depression, Alzheimer’s and parenthood. And that’s bad news. We know that a good night’s sleep helps to solidify our memories of the previous day’s experiences. And according to a new study, we need a certain amount of continuous sleep for those benefits to kick in.
From an evolutionary point of view, it seems strange that we sleep for hours on end. Rather than leaving ourselves unresponsive and vulnerable for large chunks of time, why not simply sleep over several shorter fragments?
This is not an easy question to answer. Until recently, it has been all but impossible to break up the continuity of sleep without also affecting its quality, or stressing out the animals in question. But Luis de Lecea from Stanford University has found a way. He has engineered mice with in-built silent alarm clocks. These animals can be woken up at will with a pulse of light delivered directly to their brains.
It’s been a week since the last full moon on 15th July. During this time, the odds of being attacked by a lion are highest than at any other point in the month, which is why I’ve been walking around the neighbourhood with two guard bears and a platoon of ninjas. The fact that I live in a leafy suburb of London is inconsequential. You can never be too careful. Constant vigilance.
Of course, lion attacks are more of a problem in other parts of the world. In Tanzania, lions have attacked more than a thousand people between 1988 and 2009, and eaten around two-thirds of them. Now Craig Packer from the University of Minnesota has shown that the frequency of these attacks is tied into lunar cycles.
Since 1948, people have been poisoning unwanted rats and mice with warfarin, a chemical that causes lethal internal bleeding. It’s still used, but to a lesser extent, for rodents have become increasingly resistant to warfarin ever since the 1960s. This is a common theme – humans create a fatal chemical – a pesticide or an antibiotic – and our targets evolve resistance. But this story has a twist. Ying Song from Rice University, Houston, has found that some house mice picked up the gene for warfarin resistance from a different species.
Warfarin works by acting against vitamin K. This vitamin activates a number of genes that create clots in blood, but it itself has to be activated by a protein called VKORC1. Warfarin stops VKORC1 from doing its job, thereby suppressing vitamin K. The clotting process fails, and bleeds continue to bleed.
Rodents can evolve to shrug off warfarin by tweaking their vkorc1 gene, which encodes the protein of the same name. In European house mice, scientists have found at least 10 different genetic changes (mutations) in vkorc1 that change how susceptible they are to warfarin. But only six of these changes were the house mouse’s own innovations. The other four came from a close relative – the Algerian mouse, which is found throughout northern Africa, Spain, Portugal, and southern France.
The two species separated from each other between 1.5 and 3 million years ago. They rarely meet, but when they do, they can breed with one another. The two species have identifiably different versions of vkorc1. But Song found that virtually all Spanish house mice carry a copy of vkorc1 that partially or totally matches the Algerian mouse version. Even in Germany, where the two species don’t mingle, a third of house mice carried copies of vkorc1 that descended from Algerian peers.
On the surface, it looks as if our identity as male or female is determined in the womb. The decision seems final – a genetic switch flicks towards either setting, and locks into place for the rest of our lives.
This tidy image is wrong. Two recent studies in mice have shown that the switch isn’t locked – it’s held under constant tension by two rival genes – DMRT1 and FOXL2. It’s a tug-of-war fought over sexual fate, which goes on throughout our lives. Take away either contestant, and its adversary pulls the switch to the opposite setting. Ovaries can transform into testes and vice versa, even in adults.
As of this moment, I am a full-time freelancer. I’ve just left the job I’ve had for seven years and entered the world of the vagrant scribe.
Wait, what? You had a job?
Yeah, I’ve been working at Cancer Research UK, leading a small team of information officers. This blog, and all the various things I do on the side have purely been a nights-and-weekends affair. Now, they’re moving from the periphery to the centre. It’s a bit like taking off a clamp and losing a foot in the process. I say goodbye to meetings, sign-off, commuting and office politics, but I’m also leaving some truly amazing people and some really good friends.
You’re just jumping on the bandwagon, aren’t you?
So what are you doing to do?
The basic plan is to sit on my sofa in a dressing gown, watching daytime TV and stuffing my face with crisps do more of what I do on the side: writing and talking about science, and about writing and talking about science. I’m working on four features at the moment, a few smaller but regular projects, something fun for Radio 4, a few talks, a spot of teaching at City University’s Science Journalism course, and more.
You don’t say. It’s a tough market. The pieces I collate in the weekly links are constant reminders of the sheer number of amazing science writers out there. And I’ve been led to believe that freelancing is not just about fast cars and untold riches. (It’s about unbridled power too, right? Right?) That being said, this is absolutely what I want to do and I think it’s a good time for it.
Will the blog continue?
Yes, absolutely. There shouldn’t be any dip in the frequency of posts, and if anything, I hope to make it better. The blog is a proper part of my income now, and any help with promotion – emails, Reddit submissions, tweets, shares, whatever you prefer – would be appreciated.
What would Peter Falk say?
And just one other thing…
A massive thank you to everyone who has given me invaluable advice about this, including Rebecca Skloot, David Dobbs, Jonah Lehrer, Carl Zimmer, Maggie Koerth-Baker, Frank Swain, Steve Silberman, and others I’m undoubtedly forgetting. But most of all, thanks to my wife Alice for her unerring support.
In 2007, one Jamie Langridge became $50,000 richer after winning intense national tournament in Las Vegas. Langridge beat his opponent decisively, with a classic open-hand technique. The sport? Rock-paper-scissors.
Rock-paper-scissors seems deceptively simple. Pairs of opponents display one of three hand gestures. Paper covers rock, rock blunts scissors, and scissors cut paper. It’s so straightforward that children the world over learn to play it. But this is not just a game of chance. Played at the highest level, it becomes a game of psychological strategy, one that justifies five-figure trophies in large competitions and even the publication of strategy guides.
Such advanced games are possible because people don’t choose their hand shapes randomly. They are affected by moves that have gone before, and what other people are doing. Consider a new experiment by Richard Cook at University College London. Cook asked 45 people to face off against each other in several rounds of rock-paper-scissors, in exchange for real money. In every game, either one or both players were blindfolded.
Cook found that the players drew with each other more often when one of them could see (36.3% of the matches) than when both were blindfolded (33.3% of them). The latter figure was exactly the proportion of draws you’d expect if the players were choosing randomly; the former was significantly higher than chance.