And so it ends. I joined Discover on 26th March 2010, and it’s been a fantastic run. But tomorrow, I migrate over to my new habitat at National Geographic, to join Carl Zimmer, Virginia Hughes and Brian Switek in the new Phenomena collective.
Thanks to everyone at Discover for their support during a great run, and I’m sure that the new folks, and the new bloggers like Keith Kloor, will continue the magazine and website’s great legacy.
In the meantime, I hope that all of you will help me christen my new abode. The site has been built over the last week and the transition should be pretty seamless. All of my old posts have been ported over, as have all the comments bar those of the last few weeks. So, without further ado, here are the important details:
Both of these links are not currently working – they’ll go live on tomorrow, Tuesday, probably at 9am ET.
Blog transitions are always annoying things, and there’s always a proportion of readers who get lost in the jump. If you’ve enjoyed what I’ve written here, could you please help by drumming up some interest in these first days and weeks. Update bookmarks and feeds, tell your friends and family… anything you feel happy to do. It’s all appreciated.
See you there.
Panama’s San Lorenzo forest reserve is around the size of Manhattan. For two years, this small area was host to 102 scientists, working together to count everything that crept and crawled. They came from 17 countries, and converged upon a half-hectare of the forest, about the size of half a rugby pitch. They dug into the soil, and ascended into the 40-metre-tall treetops with ropes, balloons, and a giant crane. They unleashed fogs, set up sticky traps, and hacked into pieces of wood.
Together, they were part of the largest ever systematic attempt to answer a disarmingly simple question: in a patch of tropical rainforest, how many species of insects and other arthropods are there?
After collecting the critters in 2003 and 2004, and analysing the material for eight years, they got an answer: 6,144 species in that patch of forest. Using computer simulations to scale that up, they estimate that the entire 6,000-hectare Manhattan-sized forest is home to around 25,000 arthropod species.
In a lab at Stanford University, a mouse is showing signs of depression. For around 10 weeks, it has experienced a series of irritations, from bouts without food or water, to erratic sleep patterns. Now, its motivation is low—when picked up by the tail, it makes few attempts to escape, and it doesn’t try to explore new spaces. It’s also less willing to sip from a sugary liquid– a sign that it gets less pleasure from normally pleasurable activities. It is never easy to assess the mental health of an animal, but this mouse is clearly showing some of the classic symptoms of depression.
But not for long.
Earlier, Kay Tye and Julie Mirzabekov altered the mouse so that a flash of light can activate a small part of its brain—the ventral tegmental area (VTA), near the bottom of the brain and close to the midline. A burst of light, and the mouse’s behaviour changes almost instantly. It struggles when held aloft, it explores open areas, and it regains its sweet tooth. A burst of light, and its symptoms disappear.
But on the other side of the country, at the Mount Sinai School of Medicine, Dipesh Chaudhury and Jessica Walsh are doing the same thing to completely different effect. Their mice have been altered in a similar way, so that light can also switch on their VTA neurons. But these rodents have endured a shorter but more intense form of stress—10 days of being placed in cages with dominant, aggressive rivals. Because of the resulting attacks, some of them have developed depressive symptoms. Others are more resilient. But when Chaudhury and Walsh flashed the VTAs of these mice, resilient individuals transformed into susceptible ones.
Both studies used the same methods to trigger neurons in the same part of the brain… and got completely different effects. In Tye and Mirzabekov’s experiment, depressed mice resumed their normal behaviour. In Chaudhury and Walsh’s study, the resilient mice showed more depressed symptoms.
For the last 2.5 years, I have enjoyed a cosy symbiosis with Discover, providing bloggy sustenance in exchange for shelter, like many a gut bacterium. But in a week’s time, this happy relationship will come to an end.
Next week – most likely on Tuesday 18th December, but to be confirmed – Not Exactly Rocket Science will be moving to National Geographic, as part of a small and brand-new collective of science blogs called Phenomena.
Phenomena will include three of the most accomplished science writers working today: Carl Zimmer (The Loom), Brian Switek (Laelaps), and Virginia Hughes (starting a brand new blog, Only Human). I love these people and their work, and seeing this group come together behind the scenes has been like watching Nick Fury recruit the Avengers.
In August of this year, Allison Noles rushed her bulldog Bella Mae to the vet. The dog’s face looked like a pincushion, with some 500 spines protruding from her face, paws and body. The internet is littered with such pictures, of Bella Mae and other unfortunate dogs. To find them, just search for “porcupine quills”.
North American porcupines have around 30,000 quills on their backs. While it’s a myth that the quills can be shot out, they can certainly be rammed into the face of a would-be predator. Each one is tipped with microscopic backwards-facing barbs, which supposedly make it harder to pull the quills out once they’re stuck in. That explains why punctured pooches need trips to the vet to denude their faces.
But that’s not all the barbs do. Woo Kyung Cho from Harvard Medical School and Massachusetts Institute of Technology has found that the barbs also make it easier for the quills to impale flesh in the first place. “This is the only system with this dual functionality, where a single feature—the barbs—both reduces penetration force and increases pull-out force,” says Jeffrey Karp, who led the study.
If you travelled back to Spain, during the Cretaceous period, you might see an insect so bizarre that you’d think you were hallucinating. That’s certainly what Ricardo Pérez-de la Fuente thought when he found the creature entombed in amber in 2008.
The fossilised insect of the larva of a lacewing. Around 1,200 species of lacewings still exist, and their larvae are voracious predators of aphids and other small bugs. They also attach bits of garbage to tangled bristles jutting from their backs, including plant fibres, bits of bark and leaf, algae and moss, snail shells, and even the corpses of their victims. Dressed as walking trash, the larvae camouflage themselves from predators like wasps or cannibalistic lacewings. And even if they are found, the coats of detritus act as physical shields.
We now know that this strategy is an ancient one, because the lacewing in De la Fuente’s amber nugget—which is 110 million years old—also used it. It’s barely a centimetre long, and has the same long legs, sickle-shaped jaws, and trash-carrying structures of modern lacewing larvae. But it took camouflage to even more elaborate extremes. Rather than simple bristles, it had a few dozen extremely long tubes, longer even than the larva’s own body. Each one has smaller trumpet-shaped fibres branching off from it, forming a large basket for carrying trash.
De la Fuente called it Hallucinochrysa diogenesi, a name that is both evocative and cheekily descriptive. The first part comes from the Latin “hallucinatus” and references “the bizarreness of the insect”. The second comes from Diogenes the Greek philosopher, whose name is associated with a disorder where people compulsively hoard trash.
In Southwestern France, a group of fish have learned how to kill birds. As the River Tarn winds through the city of Albi, it contains a small gravel island where pigeons gather to clean and bathe. And patrolling the island are European catfish—1 to 1.5 metres long, and the largest freshwater fish on the continent. These particular catfish have taken to lunging out of the water, grabbing a pigeon, and then wriggling back into the water to swallow their prey. In the process, they temporarily strand themselves on land for a few seconds.
Other aquatic hunters strand themselves in a similar way, including bottlenose dolphins from South Carolina, which drive small fish onto beaches, and Argentinian killer whales, which swim onto beaches to snag resting sealions. The behaviour of the Tarn catfishes is so similar that Julien Cucherousset from Paul Sabatier University in Toulouse describes them as “freshwater killer whales”.
If you want to preserve your body so that scientists will dig it up millions of years from now, there are a few standard ways of doing it. You could get buried in sediment, so your bones and other hard tissues turn into stony fossils. You could get trapped in the sap of a tree, which will eventually entomb your body in gorgeous amber. Or if that’s a bit too flashy, try snuggling up in the cocoon of a leech.
Leeches and earthworms secrete cocoons of mucus and lay their eggs inside. After a few days, the mucus hardens into a hard protective capsule that’s remarkably resistant to changes in temperature and chemical attacks. These cocoons fossilise very well, and palaeontologists have found many made by prehistoric leeches, dating right back to the Triassic period when dinosaurs first appeared.
To Benjamin Bomfleur from the University of Kansas, these cocoons are a goldmine of information into the past. In one specimen, 200 million years old, he has found the remains of a microscopic soft-bodied creature that would normally be impossible to fossilise. In the leech’s cocoon, it found a way into the present.