In a French meadow, a creature that specialises in corrupting the bodies of other animals is getting a taste of its own medicine.
Leptopilina boulardi is a wasp that lays its eggs in fly maggots. When the wasp grub hatches, it devours its host form the inside out, eventually bursting out of its dead husk. A maggot can only support a single grub, and if two eggs end up in the same host, the grubs will compete with one another until only one survives. As such, the wasps ensure that they implant each target with just one egg. And if they find a maggot that has already been parasitized by another L.boulardi, they usually stay away.
Usually, but not always.
L.boulardi is sometimes infected by a virus called LbFV, which stands for L.boulardi filamentous virus. And just as the wasp takes over the body of its maggot target, so the virus commandeers the body of the wasp. It changes her behaviour so that she no longer cares if a maggot is already occupied. She will implant her eggs, even if her target has an existing tenant. After infected wasps are finished, a poor maggot might have up to eleven eggs inside it.
I make no secret of the fact that I am President of the Carl Zimmer fan club. Carl’s writing was a big influence for me well before we became colleagues at Discover. So when Alok Jha at the Guardian asked me to write a piece analysing a great piece of science writing, I didn’t have to search very hard. You can find that piece in the Guardian today. Consider it a (short and incomplete) guide to good science writing, and an ode to a peerless chum.
It begins like this:
Scientific papers aren’t known for their catchy titles. Here’s a typical example: “Ancestral capture of syncytin-Car1, a fusogenic endogenous retroviral envelope gene involved in placentation and conserved in Carnivora.”
A good science writer could tell you what each of those technical words meant, or translate them into their everyday equivalents. They would also explain the concepts encapsulated by those words, and why they deserve your attention. And a great science writer might start with something like this: “If not for a virus, none of us would ever be born.”
Photo by Russ Creech
Here’s the fourth piece from my new BBC column
In The Truth Machine, a science-fiction novel published in 1996, scientists invent a device that can detect lies with perfect accuracy. It abolishes crime, changes the world, and generally saves humanity from self-destruction. Which is nice.
Could such a machine ever be a reality? Not if our current technology is anything to go by. The polygraph has been around for almost a century, with wired-up offenders and twitching needles becoming a staple of criminal investigations. But there is no solid evidence that the signs it looks for – faster heart rates, shallower breaths and moist skin – can accurately indicate whether someone is telling a lie. Underpinned by fluffy theory and backed by a weak and stagnant evidence base, this lie-detection device is unlikely to get any better.
Inside the brain
Abandoning the polygraph, some scientists have turned to brain scanners. Two technologies have dominated the field. The first uses electronic sensors on a person’s scalp to measure an electrical signal, or “brainwave”, called the P300, which appears when we recognise something. By looking for this signal, you could potentially tell if someone is hiding knowledge about something they are already familiar with, like a murder weapon. This is certainly useful, but it is a long way from an all-purpose lie-detection method, and two of the key figures in the field have been arguing about how effective this is for many years.
The second technique is functional magnetic resonance imaging (fMRI), affectionately known as blobology for the colourful pictures it produces. It shows the location of firing neurons in an indirect manner, by tracking the blood flow that supplies them with nutrients and oxygen. Several fMRI studies have shown that some parts of the brain are consistently more active when people tell untruths rather than truths, particularly areas at the very front that help us to suppress unwanted actions. Successful lying, it seems, is mainly about repressing the urge to be honest.
It’s Easter. For some of people, this means they can take up all the vices they gave up for Lent, and binge on chocolate till they feel sick. For the hyenas of northern Ethiopia, it means it’s time to stop hunting donkeys.
Spotted hyenas are unfussy eaters and incredible opportunists. They can feast on rotting meat, anthrax-infected corpses, garbage and dung. They digest their food so completely that their droppings tend to consist of hair, hooves, and white powder made from broken-down bones. Unsurprisingly, they do rather well near urban environments, where humans provide them with a bonanza of scraps, leftovers, and livestock. The hyenas of northern Ethiopia get almost all of their food by scavenging on such sources.
Local humans tolerate the hyenas, which are affectionately known as “municipal workers”. The animals clean the waste from butchers, households, and even the local veterinary college. They’re seen and heard almost every night, and they almost never attack humans. Instead, they have come to depend on the Ethiopians for their food.
But that changes in the run-up to Easter. For 55 days, the local Orthodox Christians go through a period of fasting. Meat goes off the menu, and few animals are slaughtered. This lack of demand creates supply problems for the hyenas. Gidey Yirga from Mekelle University in Ethiopia has found that they sate their hunger by hunting instead.
Apathy, weary sighs, and fatigue: these are the symptoms of the psychological malaise that Carl Zimmer calls Yet Another Genome Syndrome. It is caused by the fast-flowing stream of publications, announcing the sequencing of another complete genome.
News reports about such publications tend to follow the same pattern. Scientists have deciphered the full genome of Animal X, which is known for Traits Y and Z, which could include commercial importance, social behaviour, being closely related to us, or just being exceptionally weird. By understanding X’s collection of As, Gs, Cs and Ts, we may gain insights into the genetic basis of Y and Z, which will be terribly important and there will be parties and cake.
Note the future tense. The value in sequencing yet another genome is almost never in the act itself, but in enabling an entire line of subsequent research. It’s the harbinger of news; it’s rarely news itself.
But there are exceptions. This week, there’s a paper about a new animal genome that goes the extra mile. It includes not just one full sequence, but twenty-one. It doesn’t just spell out the creature’s DNA, but also uses it to address some big questions in evolutionary biology. And its protagonist is a small, unassuming fish – the three-spined stickleback.
Yutyrannus, by Brian Choo
Meet the largest feathered animal in history – an early version of Tyrannosaurus rex, clad in long, fuzzy filaments. This newly discovered beast has been named Yutyrannus huali, a mix of Mandarin and Latin that means “beautiful feathered tyrant”. And its existence re-opens a debate about whether the iconic T.rex might have been covered in feathers.
“This is a tremendously important fossil. Paleontologists have been waiting for a gigantic feathered theropod to turn up for some time,” says Lindsay Zanno from the Field Museum. Larry Witmer from Ohio University, agrees. “The big thing is the one-two punch of being huge AND feathered,” he says.
Yesterday, I attended a conference at the Royal Society to discuss the controversial studies on mutant H5N1 flu viruses that can spread between mammals. It was the first time that the two scientists behind the papers – Yoshi Kawaoka and Ron Fouchier – have appeared in public together since the controversy broke, and Kawaoka spoke openly about his results.
The search for new treatments for infectious diseases gets a lot of attention. But to treat something, we first need to know what we’re dealing with. That’s not always easy. The backbone of diagnosis is still built from old methods that include growing mystery germs in lab cultures, or checking how they react to specific chemicals. These techniques require special training and can be time-consuming. Unlike medical dramas, where diseases can be diagnosed between quips, the real-life work can take days.
Amy Barczak from Massachussetts General Hospital is developing a diagnostic technique based on RNA, a molecule that is closely related to DNA. Her method can detect a wide range of infections microbes (‘pathogens’), from bacteria to viruses to parasites. At the same time, it can tell if they are resistant to drugs. Barczak has now published an early “proof-of-principle” study showing that her method has potential, but she says that “considerable additional work will be required” to create a test for doctors to use.
It seems odd that diagnosis should be a problem for the age of modern genetics. Surely you could just sequence the DNA of whatever it is that’s causing an illness? That’s true, in principle. In practice, you need to know the genome of the pathogen in question, and you need to boost the amount of DNA in your sample. It’s even harder to scan antibiotic resistance, because there are hundreds of ways in which pathogens can tweak their genes (or gain new ones) that make them invulnerable. We know of only a fraction of them.
RNA offers an easier path. When genes are ‘switched on’, the information encoded within their DNA is transcribed into equivalent molecules of RNA. If a pathogen has DNA sequences that reveal its identity, it also has corresponding telltale RNA sequences. And of the two molecules, RNA is far more abundant. You can measure it straight from a patient’s sample, without needing to purify or amplify it.
Late last year, two teams of scientists announced that they had mutated the H5N1 ‘bird flu’ virus so that it can spread easily between mammals, an ability that their wild cousins lack. The research aimed to understand how natural viruses could evolve into more dangerous forms. But it also raised concerns that the mutant strains could cause a pandemic if they were accidentally released or used in a terrorist attack. (For the background to this controversy, here’s my explainer.)
Last year, the US National Science Advisory Board for Biosecurity (NSABB) – an independent advisory board to the government – recommended that both papers should be published with significant redactions. The full information would only be released to selected scientists. But on 30 March, after a two-day meeting, the NSABB announced that it had changed its mind.
The scientists who led the research – Ron Fouchier from Erasmus Medical Center in Rotterdam, and Yoshihiro Kawaoka from University of Wisconsin-Madison – have since revised their papers. The NSABB voted unanimously to publish Kawaoka’s altered manuscript. Fouchier’s was more contentious, but the board voted 12 to 6 in favour of publishing it.
These recommendations are not the final word. Both manuscripts still have to go through the usual process of peer review, and the US government hasn’t weighed in yet. But should the process now go smoothly, nothing will be redacted from either paper. Fouchier has confirmed that his manuscript will include the full genetic sequence of his mutant strain.
What prompted this U-turn? Fouchier and Paul Keim, acting chair of the NSABB, spoke about the decision at a press conference this morning, held ahead of a Royal Society meeting on Tuesday and Wednesday.