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Archive for June, 2010
Behold Leviathan Livyatan: the sperm whale that killed other whales
This is one of the first of our shiny new Discover galleries, loaded with great Livyatan pics. The full article is below.
Update: This animal has been renamed! It used to be Leviathan until someone pointed out to the authors that the name had already been taken!
In today’s oceans, killer whales hunt other species of whales, working in packs to take down their much bigger prey. But living whales have it easy. Those that swam off the coast of Peru around 12 million years ago were hunted by a far bigger predator, a recently discovered animal with a very appropriate name: Livyatan.
Livyatan melvillei, named after the Biblical sea monster and the author of Moby Dick, was a giant sperm whale that has just been discovered by Belgian scientist Olivier Lambert. At between 13.5 and 18.5 metres in length, it was no bigger than the modern sperm whale, but it was clearly far more formidable.
Today’s sperm whale has no functional teeth in its upper jaw and only small ones in its lower jaw (which are mostly used in fights). It feeds through suction, relying on a rush of water to carry its prey into its open mouth. But Livyatan’s mouth was full of huge teeth, the largest of which were a foot long and around 4 inches wide. This was no suction feeder! Livyatan clearly grabbed its prey with a powerful bite, inflicting deep wounds and tearing off flesh as killer whales do, but with a skull three times bigger.
Does national IQ depend on parasite infections? Er…
[I was originally going to avoid this, but decided to do it for the critical analysis, because I suspect it will be widely but badly covered, and because I also suspect that very little of this coverage will point out the publication record of these authors. Which is worth pointing out. Have fun in the comments!]
Why do different countries have different IQs? You’d first answer probably has something to do with education, but a trio of US scientists have put forward a radically different hypothesis – international variation in intelligence is related to the prevalence of parasites in a country. As is, according to them, pretty much ever y major aspect of human culture (but more on this later)…
Christopher Eppig, Corey Fincher and Randy Thornhill (yes, that one) from the University of New Mexico have suggested that fighting off parasitic infections during childhood takes up valuable energy that might otherwise go towards the development of the brain. More parasites mean less well developed brains and weaker mental abilities.
Giant dinosaurs used the planet to warm their eggs
At Argentina’s Sanagasta Geological Park, there is a volcanic nursery for giants. It’s a site that is strewn with the fossilised eggs of giant dinosaurs – sauropods. Each of their 80 or so egg clusters sits next to a geyser, a hot vent or other volcanically heated sites. This is no coincidence – eggs need moisture and heat to incubate properly and big eggs are particularly demanding. These dinosaurs were using the planet to keep their babies warm.
Argentina is a haven for any palaeontologist looking for dinosaur eggs. Different provinces have yielded several large nesting sites. Most belonged to the giant sauropods and some even contain eggs with fossilised embryos inside. The sites have told us much about how dinosaurs looked after their young and even what ate baby dinosaurs but until now, scientists have largely ignored the question of why these particular sites were such inviting locations for expectant dinosaurs.
Ambush ants capture giant prey using Velcro principles
In the Brazilian rainforest, a grasshopper lands on a leaf and seals its fate. It was after a quick meal, but this leaf belongs to the Cecropia obtusa plant and it employs hidden bodyguards – ants. Underneath its leaves, thousands of Azteca andreae ants lie in ambush, poised at the edges with their jaws outstretched. As soon as the grasshopper lands, the ants rush out from their hiding places, seize it by the legs and pull it spread-eagled. The leaf turns into a medieval torture rack, with the ambushers holding the victim while their nestmates bite, sting and dismember it.
This hunting strategy is all the more amazing when you consider that the ants weigh just over a milligram each while their prey – including grasshoppers and moths – can weigh up to 10 grams. Ants are famously strong and they obviously hunt in large numbers, but even so, holding down a struggling insect that outweighs them by around 10,000 times can’t be easy. It’s the equivalent of a team of humans holding down three struggling blue whales.
Photo safari – bateleur eagle
This is a bateleur, an unmistakeable African eagle, with distinctive black, red and white colours and a very short tail. My wife took this photo on our South African safari. I’m amazed at how precise the composition is given that the bird was just circling overhead.
Saturday links
The week’s research
- fMRI is a controversial technique, not least because studies that use it are often overinterpreted and there are still some fundamental unanswered questions about how to interpret its results. Now, SciCurious talks about a new study that helps to tell us exactly what those pretty brain pictures mean.
- At Scientific American, Ferris Jabr discusses the minor third, a chord that conveys sadness in both speech and music. “When it comes to sorrow, music and human speech might speak the same language.”
- Butterfly wings are beautifully colourful but the colours come not from pigments but from the structures of the wings at a microscopic level.
- Ratcheting up the competitive pressure just encourages students to cheat more, rather than to cooperate, says the BPS Research Digest blog.
- Human pluripotent stem cells (reprogrammed from adult cells) have been created using a viral vector without any genes, says Elie Dolgin at Nature News. “This was the control experiment that went wrong, effectively.”
- Brandon Keim writes about a leaping fish that thrives on land. Apparently, it engages in awesome aerial duels, like Yoda in Episode II.
- We have sequenced the body louse genome. The significance isn’t a head-scratcher. I’ll get my coat.
- A 30-million-year old fossil pelican tells us that even back then, they looked silly.
- Climate change contrarians are in the vast minority, and lack scientific credibility and expertise, according to a new PNAS study discussed in Scientific American. I’m shocked, shocked I tell you.
- The bones of Caravaggio have been found and they reveal what killed him – lead poisoning from his paints.
- Egyptian vultures use twigs to gather wool for nests, says Michael Marshall in New Scientist’s Zoologger.
- Four-legged creatures may have gained a foothold by ditching genes guiding fin development, according to Janelle Weaver in Nature.
- The origin of the mysterious condition known as blindsight has been revealed.
More science
- It’s the 10th anniversary of the human genome. Nature has some great coverage. Meanwhile, sequencing a genome is faster and cheaper, but is it better, asks Michael Le Page.
- In which we fail the whale: a whaling ‘peace deal’ has fallen apart
- Jonah Lehrer on metacognition –the feeling of knowing what you know. We do this quickly and accurately. “The metacognitive brain is able to almost instantly make an assessment about all the facts, errata and detritus stuffed into the cortex.” And Vaughan Bell has more.
- While England were busy drawing against Algeria, a much more interesting turns of events was playing out – the FDA’s advisory panel rejects a drug called flibanserin, designed to tackle the so-called “Hypoactive Sexual Desire Disorder” in women. Petra Boynton has the story and an excellent breakdown of why this is a victory for science.
- When scientists attack – over at the Primate Diaries, there’s a little dust-up afoot about cultural learning in chimpanzees.
- Tor Wager, a scientist trying to understand the placebo effect.
- ScienceNews evaluates claims around voice-based lie detection, the latest technology that claims to do a better job than the polygraph, but doesn’t (*cough*fMRI*cough*)
- Science writers are fond of saying that the human genome’s total count of 20,000 genes came as a surprise to everyone. Not so, says John Hawks. At least one person predicted that in 1948.
- London is being invaded by dinosaurs. The Walking with Dinosaurs arena show is on and at NPR, one of the actors from the New York show talks about what it’s like to place a baby T.rex. “I base a lot of, to be honest, a lot of the characterization off of my dog.” Meanwhile, giant pterosaurs fly in the SouthBank.
- A single paper can shove a journal’s impact factor from around 2.5 to 50. Which does make them seem a touch useless, doesn’t it?
- A frozen Siberian mammoth is heading to France to be bombarded with gamma rays. MAMMOTH SMASH.
- You really ought to be following Linda Geddes’s Bumpology series at New Scientist, where she is effectively blogging her pregnancy. But with SCIENCE.
- One reason why humans are special and unique: We masturbate. A lot. Jesse Bering’s long feature at Scientific American goes on an on an ism…
Awesome
- This video of a young chimp investigating a hidden camera is the best piece of wildlife filmmaking I think I’ve ever seen. It’s incredibly moving. Just look at those eyes.
- Bad Astronomy has probably the best aurora photo I’ve ever seen. Taken from space, no less.
- Onion: Eons of Darwinian evolution somehow produce Mitch.
- A giant spider crab sloughs off its shell in time lapse
Journalism, communication and the internet
- Ah, Jonathan Leake, he of the embargo-breaking nominative determinism. If you’re going to repeatedly publish science news ahead of everyone else, perhaps you might think to make the story actually, y’know, not be shit? This week, the Sunday Times retracted Leake’s bogus story on a “bogus rainforest claim” by the IPCC that turned out not to be very bogus after all. Happily.
- Ivan Oransky discusses the Ingelfinger Rule, and why scientists (as well as journals) don’t want other scientists scooping them.
- “Bring on the bloggers, do. Some of them are very clever. But you have to admit that they are also a bit weird.” Heh. Alice Bell talks about why citizen science still needs specialists. She also introduces the concept of monitorial citizenship, which she expands on (together with some great ideas around expertise) on her own blog.
- Bora Zivkovic takes those ideas and runs with them, talking about how journalists become “temporary experts” on whatever they’re reporting on.
- “The media, rather than informing people, now merely report on public ignorance. Do our viewers agree?” I love XKCD
- Social reading via the Kindle (and the NYT)
- Andrew Maynard sings praises for I’m a Scientist, Get Me Out of Here, an idea that he (quite rightly) wants to see in other countries.
- T DeLene Beeland interviews me for the Charlotte Observer. I love the big picture, simply captioned “Yong”.
Heavy, rough and hard – how the things we touch affect our judgments and decisions
When you pick up an object, you might think that you are manipulating it, but in a sense, it is also manipulating you. Through a series of six psychological experiments, Joshua Ackerman from the Massachusetts Institute of Technology has shown that the properties that we feel through touch – texture, hardness, weight – can all influence the way we think.
Weight is linked to importance, so that people carrying heavy objects deem interview candidates as more serious and social problems as more pressing. Texture is linked to difficulty and harshness. Touching rough sandpaper makes social interactions seem more adversarial, while smooth wood makes them seem friendlier. Finally, hardness is associated with rigidity and stability. When sitting on a hard chair, negotiators take tougher stances but if they sit on a soft one instead, they become more flexible.
These influences are not trivial – they can sway how people react in important ways, including how much money they part with, how cooperative they are with strangers, or how they judge an interview candidate.
Lungs rebuilt in lab and transplanted into rats
In a lab at Yale University, a rat inhales. Every breath this rodent takes is a sign of important medical advances looming on the horizon, for only one of its lungs comes from the pair it was born with. The other was built in a laboratory.
This transplanted lung is the work of Thomas Petersen and a large team of US scientists. Their technique isn’t a way of growing a lung from scratch. Instead it takes an existing lung, strips away all the cells and blood vessels to leave behind a scaffold of connective tissues, and re-grows the missing cells in a vat. It’s the medical equivalent of stripping a house down to a frame of beams and struts and rebuilding the rest from scratch. The whole process only took a few days and when the reconstituted lung was transplanted into a rat, it worked.
Baby’s first bacteria depend on route of delivery
They are mum’s first gift to her newborn baby on the day of its zeroeth birthday – bacteria, fresh from her vagina. Vaginal bacteria are among the trillions of microscopic hitchhikers that share our bodies with us. Collectively known as the ‘microbiota’, these passengers outnumber our own cells by ten to one. Children partly inherit their microbiota from their mothers. During birth, they pass from the largely bacteria-free conditions of the womb through the microbe-laden vagina into the equally bacterial outside world.
Being slathered in vaginal microbes might not seem like much of a treat from our adult perspective, but to a newborn, it’s a key event. The microbiota are important partners, influencing our physiology and our risk of disease. Now, Maria Dominguez-Bello from the University of Puerto Rico found that the way we enter the world determines the identities of our first bacterial colonisers. Babies delivered by Caesarean section end up with a very different portfolio to those who are born naturally.
Who are you calling weak? Human jaws are surprisingly strong and efficient
Stephen Wroe has built a career out of analysing some of the planet’s most formidable skulls. His group at the University of New South Wales have studied the strength, sturdiness and biting power of the sabre-toothed cat, the great white shark, and the Komodo dragon. Now, he has turned his attention to a predator whose skull is far less impressive but yields surprises all the same – us.
Humans, it is said, have relatively weak jaws that can’t inflict or withstand high bite forces. Some have suggested that we are adapted to eat foods that aren’t very tough, or that our use of tools and cooking has lessened the evolutionary pressure on maintaining sturdy jaws. Some have even suggested that our weedy jaw muscles made way for our large brains and thus facilitated their evolution. But according to Wroe, all of these explanations have a fatal flaw – our jaws aren’t weak at all. They’re actually remarkably efficient for a primate.
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