Archive for November, 2011

Cross-dressing raptors avoid violence

By Ed Yong | November 8, 2011 7:00 pm

Male and female marsh harriers should be easy to tell apart: the males have grey wing-tips and tails, while the females are mostly brown with distinctive creamy heads. The males also tend to be around 30 percent smaller. But looks can be deceptive. In western France, many of the “female” harriers are actually cross-dressing males that permanently wear the plumage of the opposite sex. Audrey Sternalski has found that this unusual costume allows them to lead more peaceful lives.

Forty percent of male marsh harriers don female costumes, and they start wearing them from their second year of life. Their feathers have the same colours, and they’re smaller in size. Only their irises give them away – they are pale, rather than the ochre-brown of females or the yellow-white of males.

To test the effect of these colours, Sternalski created model harriers and placed them in the territories of real ones. He found that males attacked the male decoys twice as often as either the female or female-like ones. So, by looking like females, male harriers become the beneficiaries of a “non-aggression pact”. They can get access to resources and mates without incurring the wrath of other males. Indeed, Sternalski found that typical males were forced to nest twice as far from another male as the female-like males did.

Sternalski also found that the female-like males almost never attacked male decoys. Instead, they were more likely to attack other females (or female-like males), just as true females are. Not only did they look like females, they behaved like them too.

This raises several questions – are the female-like males simply doing a superficial impersonation, or are they “female” at a deeper physiological level? To find answers, Sternalski now plans to study the genetic basis of the harrier’s female mimicry.

The marsh harrier is one of only two birds whose males permanently don the colours of females. The other – the ostentatious ruff – also uses its disguise to avoid aggressive assaults. They sneak into the territories of more dominant males and surreptitiously mate with the resident females. Such strategies are fairly common in the animal kingdom – they’re found in ants, wasps, fish, and more. In most cases, the deceptive males get some sneaky sex, or avoid attacks from rivals.

But that’s not necessarily the case. In 1985, scientists discovered that some male red-sided garter snakes release a female pheromone that attracts big clusters of up to 17 amorous suitors. By luring these males to him, the female mimic more easily mates with an actual female. The goal seems obvious: distract other males. But the same group later showed that the female-mimics might simply benefit by drawing heat from the writhing balls of other duped males.

Reference: Sternalski, Mougeot & Bretagnolle. 2011. Adaptive significance of permanent female mimicry in a bird of prey. Biology Letters http://dx.doi.org/10.1098/rsbl.2011.0914

More on mimicry:

Computer gamers develop problem-solving algorithm that beats scientists’ best efforts

By Ed Yong | November 7, 2011 3:00 pm

A group of computer gamers are making habit of outshining scientists at their own game. Most of them have no scientific background, but they have a track record of cracking tough scientific puzzles, including at least one that went unsolved for over a decade. They are the Foldit players, and for their latest trick, they’ve shown that they can not only solve hard problems, but also create problem-solving tools that outperform the best in the business.

Foldit is an online multiplayer game, created by Seth Cooper and Zoran Popovic at the University of Washington. It’s designed to tap the collecting problem-solving skills of thousands of people, by reframing scientific problems in a way that even a complete novice can tackle.

In the game, players work together to decipher the structures of proteins. These molecules are feats of biological origami; they consist of long chains of amino acids that scrunch up into complicated three-dimensional shapes. Scientists need to resolve these shapes to understand how the proteins work, and the usual methods involve bouncing X-rays off purified crystals (which is difficult) or using predictive software (which is imperfect). Cooper and Popovic went down a third route: they got gamers to play their way to a solution.

Read More

CATEGORIZED UNDER: Select, Technology, Video games

Stone-cutter finds fossil whale in marble slabs

By Ed Yong | November 7, 2011 2:00 pm

In July 2002, an Italian man named Mr Francioni found something strange. Francioni owns a marble-cutting company in the Tuscan town of Pietrasanta, and he had just acquired a block of Egyptian marbleized limestone. After slicing the block into six slabs, he discovered the fossilised bones of an animal within. Fossils weaken the strength of cut stone and many people discard them outright. But Francioni was excited: he thought he had found a dinosaur, and contacted the nearby University of Pisa.

He got through to Giovanni Bianucci. “As soon as I saw the slabs, I realized that the finding was even more important than a dinosaur, at least for me. I study marine mammals,” he says. Bianucci realised that the bones belonged to an archaeocete, one of the predecessors of modern whales and dolphins. The story might have ended there: Francioni already had an offer from a foreign private collector, who wanted to slabs for his living room. Thankfully, Pisa’s local government intervened. They bought the fossils for the University’s Natural History Museum, where they are now on permanent display.

Read More

I've got your missing links right here (4 November 2011)

By Ed Yong | November 5, 2011 12:00 pm

Top picks

I’ve started a new Tumblr blog called Nature Wants to Eat You: a celebration of the animal kingdom’s terrifying mouths, jaws, teeth and tongues.

A truly superb comic on depression

Modern journalism involves long, complex stories that require flexible reporting, says Emily Bell, citing Occupy Wall Street as an example.

A masterful summary of Ben Goldacre’s eight years of writing Bad Science. Much to like, but particularly: “People who don’t understand science can only critique in terms of motive. Let them have that; we’ll do the details.” Also good to know that Goldacre is writing a book on evidence misuse by pharma.

With Vaccines, Bill Gates Changes The World Again – a great feature by Matthew Herper

Two women in a canoe happen upon a flock of starlings. Incredible video ensues.

Unfeasibly, the Toxoplasma story gets more mental with every new paper. And Carl Zimmer is there to chronicle it all.

What does it mean to be a science journalist? A great, thoughtful piece from Marie-Claire Shanahan.

Research into a male birth control pill involves 50 yrs, vitamin A, booze & many bad jokes. Also, the potential compound is called “Win”. By Virginia Hughes.

There is LOTS to love about Nature’s autism special this week.

Fly On Wall Sees Things It Wishes It Hadn’t, by Rob Dunn

From Big Bangs to God Particles – why science depends on good branding, by John Pavlus.

A series of incredible paper sculptures were left anonymously at a Scottish library.

An epic piece of editing: Four Ways Men Stunt Women’s Careers Unintentionally

“Why Is This Cargo Container Emitting So Much Radiation?” A great Wired story.

How walking through a doorway increases forgetting, by Christian Jarrett.

The case of Diederik Stapel – Dutch psychologist who faked much of his data – just gets worse. Thirty-plus papers included fraud. “Many of Stapel’s students graduated without having ever run an experiment. Meanwhile, The Washington Post has the best headline. And the Neuroskeptic asks “Whose job is it to catch scientific fraud?” At the moment it’s up to heroic individuals.

I’ve been waiting for something like this – big blow-by-blow feature on Fukushima’s first 24 hrs, by Eliza Strickland.

The evolution of overconfidence, explained via Jersey Shore and a bottle of Jagermeister, by Scicurious

A great piece on Carl Gustafson, an archeologist whose claim of a pre-Clovis mastodon kill was rejected until now.

“The anthrax vaccine is a truly bad idea”, says Prof who sequenced anthrax in 2001 attacks.

Judith Curry Opens Mouth, Inserts Foot: a superb takedown, regarding BEST and the statistics of recent “lack of global warming

Alternative literature“. Wonderful. Don’t miss the alt-text.

Read More

CATEGORIZED UNDER: Links

Stunning wren duets are conceived as a whole but sung in two parts

By Ed Yong | November 3, 2011 2:00 pm

In the mountainous forests of Ecuador, you might hear this fast, lilting song:

The melody sounds like it comes from a single bird, but it is actually sung by two: one male and one female. The couple alternates their syllables with almost unbelievable precision, each one placing its notes in the gaps left by its partner. The result is one of nature’s finest duets. And the singers are a pair of (rather drably named) plain-tailed wrens.

By studying the singing wrens, Eric Fortune from Johns Hopkins University has found that each bird has brain circuits that encode the entire song. Rather than focusing on just their own contribution, they process the whole melody. Their duet is conceived as a whole in both their brains, but emerges as two distinct parts, one from each beak.

Read More

Extending healthy life by getting rid of retired cells

By Ed Yong | November 2, 2011 2:00 pm

As we get older, many of the cells in our bodies go into retirement. Throughout our lives, they divided time and again, all in the face of radiation bombardments and chemical attacks. Slowly but surely, their DNA builds up damage to that threatens to turn them into tumours. Some repair the damage; others give up the ghost. But some cells opt for a third strategy – they shut down. No longer growing or dividing, they enter a state called senescence.

But they aren’t idle. Senescent cells still secrete chemicals into the body, and some scientists have suggested that they’re responsible for many of the health problems that accompany old age. And the strongest evidence for this claim comes from a new study by Darren Baker from the Mayo Clinic College of Medicine.

Baker has developed a way of killing all of a mouse’s senescent cells by feeding them with a specific drug. When he did that in middle age, he gave the mice many more healthy years. He delayed the arrival of cataracts in their eyes, put off the weakening of their muscles, and held back the loss of their body fat. He even managed to reverse some of these problems by removing senescent cells from mice that had already grown old. There is a lot of work to do before these results could be applied to humans, but for now, Baker has shown that senescent cells are important players in the ageing process.

Read More

Fossil eyes show wraparound three-dimensional vision, half a billion years ago

By Ed Yong | November 1, 2011 8:00 pm

Each of our eyes sees a slightly different view of the world, and our brain combines these signals into a single three-dimensional image. But this only works in one direction, because our eyes face straight ahead and their respective fields of vision only overlap in a narrow zone. But there was once a creature that had binocular vision in a massive arc around its body, not just in front but to the sides as well. It’s called Henningsmoenicaris scutula and it lived around half a billion years ago.

H.scutula lived in the Cambrian period, the part of Earth’s history when most of today’s major animal groups exploded into existence. It was a crustacean, one of the earliest members of the group that includes crabs, prawns and lobsters. It was just a millimetre long and almost totally encased within a bowl-shaped shield. From beneath the shield, weird spike-tipped legs propelled it along, while two stalked eyes, each just half a millimetre across, peered out at the Cambrian oceans.

These eyes are compound ones, made up of several units or ‘ommatidia’. They’ve also withstood the test of time. Their organic tissues have since been converted into the mineral apatite, and the resulting fossils perfectly retain the shape and angle of each ommatidium. The eyes are so well-preserved that Brigitte Schoenemann from the University of Bonn could use them to reconstruct how H.scotula saw the world to a “quite impressive degree”.

Read More

Science writing I’d pay to read – October 2011

By Ed Yong | November 1, 2011 8:59 am

It’s time for October’s Science Writer Tip-Jar picks. For those new to this, here’s the low-down:

Throughout the blogosphere, people produce fantastic writing for free. That’s great, but I believe that good writers should get paid for good work. To set an example, I choose ten pieces every month that were written for free and I donate £3 to the author. There are no formal criteria other than I found them unusually interesting, enjoyable and/or important.

I also encourage readers to support these writers through two buttons on the sidebar. There are two ways to help. Any donations via “Support Science Writers” are evenly distributed to chosen ten at the end of the month. Donations via the “Support NERS” button go to me; I match a third of the total figure and send that to the chosen writers too.

So without further ado, and in no particular order, here are the picks:

CATEGORIZED UNDER: Tip jar
NEW ON DISCOVER
OPEN
CITIZEN SCIENCE
ADVERTISEMENT

Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!

Not Exactly Rocket Science

Dive into the awe-inspiring, beautiful and quirky world of science news with award-winning writer Ed Yong. No previous experience required.
ADVERTISEMENT

See More

ADVERTISEMENT
Collapse bottom bar
+

Login to your Account

X
E-mail address:
Password:
Remember me
Forgot your password?
No problem. Click here to have it e-mailed to you.

Not Registered Yet?

Register now for FREE. Registration only takes a few minutes to complete. Register now »