Science Tuesday - Pollen, Cannibalism, and The Big Bang Theory

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Like Origami, Pollen Grains Fold Just So
By HENRY FOUNTAIN, The New York Times, April 26, 2010

After it is released from a flower’s anther, a pollen grain walks a humidity tightrope. It dries up a bit as it travels through the air, the cellular material inside becoming dormant so it survives until it reaches the humid environment of another flower’s stigma. But it can’t become so dry that the material dies.



Pollen grains achieve the proper state of desiccation by folding in on themselves as they dry, which reduces the rate of water loss (and also accommodates the reduced volume of water, making the grain smaller). It’s an elegant trick, and the structure of the pollen grain wall determines how it occurs, according to research published in The Proceedings of the National Academy of Sciences.

Eleni Katifori, previously at Harvard and at Rockefeller University, and colleagues studied the folding of pollen from lilies and other flowers (a video of folding grains is at nytimes.com/science). The walls of pollen grains have weaker, more flexible sections called apertures, and Dr. Katifori said those sections guide the folding process. Like origami, in which paper stretches only at the creases, pollen grains deform at the apertures “so the rest can fold without stretching,” she said.

“It’s like pulling the air out of a beach ball,” she said. “Parts of the wall have to comply to accommodate the change of volume.”

Dr. Katifori said the goal of the research was to discover the basic principles by which the folding occurs as a way of understanding some of the functional demands that drive the great diversity of pollen grain structures in nature. But she said that the work might also prove useful to those who design structures. “I could imagine that engineers could get inspiration from just looking at pollen grains,” she said.







Three-Spined Stickleback Proves a Purposeful Cannibal
By HENRY FOUNTAIN, The New York Times, April 26, 2010

It’s a fact of life in the animal world that some fish (and birds, mammals, reptiles, insects, crustaceans — you name it) eat their young.

The three-spined stickleback, a species found around much of the globe, is one such finned filial cannibal. The males, who care for the eggs, are known to devour whole or parts of clutches. Sometimes, however, they might have reason to — since sticklebacks are known to “sneak” fertilizations, another fish might be the father of some of the eggs.



A study by Marion Mehlis of the University of Bonn in Germany and colleagues looked at the question of whether a male stickleback somehow assessed the paternity of the eggs in its care in deciding whether or not to eat them.

As they report in The Proceedings of the Royal Society B: Biological Sciences, the answer was yes. What’s more, the researchers found that the fish made fairly fine-tuned decisions.

The researchers manipulated the clutches that individual males cared for, replacing up to 100 percent of the eggs fertilized by the male with eggs fertilized by another male. They found that the higher the percentage of “alien” eggs, the more likely the male was to completely cannibalize the clutch. The researchers suggest that the fish probably take their cues from the odor of the developing eggs as the paternal genes start to kick in.

Cannibalism of a clutch with a high proportion of alien eggs makes sense for the fish, because it avoids putting a lot of energy into producing offspring that carry another fish’s genes, and because by eating the eggs it gets energy to rear future clutches of its own eggs.







Exploring the Complexities of Nerdiness, for Laughs
By DENNIS OVERBYE, The New York Times, April 26, 2010

BURBANK, Calif. — Shudders and groans went around the blogs and coffee rooms of the physics world back in the summer of 2007, when CBS announced plans for a new comedy series about a pair of nerdy physicists and their buxom blonde waitress neighbor.

After all, the characters, Sheldon Cooper, a gangly supremely confident theoretical physicist at a place a lot like the California Institute of Technology, who has an IQ of 187 and entered college at 11, and his roommate, Leonard Hofstadter, whose IQ is only slightly less lofty at 173, and who is instantly smitten by the waitress next door, would seem to embody all the stereotypes that scientists have come to hate: physicists are geeky losers, overwhelmingly male and ill at ease outside of the world of Star Trek.

Not to mention their pals Rajesh Koothrappali, who literally cannot speak in the presence of a pretty woman, and Howard Wolowitz, who can’t shut up, and Penny, who works at the Cheesecake Factory and doesn’t seem to know Newton the Isaac from Newton the fig.

Three years later some scientists still say that although the series, “The Big Bang Theory” (Monday nights on CBS), is funny and scientifically accurate, they are put off by it.

“Makes me cringe,” said Bruce Margon, an astrophysicist at the University of California, Santa Cruz, explaining, “The terrible stereotyping of the nerd plus the dumb blond are steps backwards for science literacy.”

But other scientists are lining up for guest slots on the show, which has become one of highest rated comedies on television and won many awards. The Nobel laureate George Smoot of the University of California, Berkeley, and the NPR Science Friday host Ira Flatow, have appeared on the show.



Lisa Randall, a Harvard particle theorist who has visited the show’s set twice and appeared as an uncredited extra in one scene said, “I do think the writers are genuinely clever.”

Lawrence Krauss, a cosmologist at Arizona State, and author of “The Physics of Star Trek,” said he had changed his initial dire opinion about the program. “First, because it is funny, and continues to be,” he said. “Second, because the characters have developed softer edges, and one of them has the girl!”

Sheldon and Leonard are not cool, but they have turned out to be lovable.

They were born out of brainstorming sessions Chuck Lorre and Bill Prady, the show’s producers, were having for a new program about a young woman out on her own. Mr. Prady started reminiscing about people he had known during his own days as a computer programmer in New York, like the guy who could do complicated mathematical conversions in his head, but could not figure out the tip in a restaurant, because he did not know how to quantify “service.” Their female character, they decided, should be a bridge into the world of such people, who can speak Klingon but do not know how to ask a woman out on a date. The show would be about the feeling, as Mr. Lorre described it, of “not quite fitting and understanding the rules of the road.”

In the show’s hierarchy of nerddom, Sheldon, played by Jim Parsons, is the king, socially clueless and irritatingly, rigidly rational (his former roommate left the words “Die Sheldon, Die” painted on the walls of his room), while Leonard, played by Johnny Galecki, is more of an everyman, trying to break out of his shell. “Leonard is in the most discomfort, he wants to move through the world,” said Mr. Lorre; Sheldon doesn’t care. Leonard’s efforts to establish and then maintain a romantic relationship with Penny have constituted a major part of the narrative arc of the first three seasons.

How does it feel to be such a freak? During a break from rehearsals recently, Mr. Parsons and Mr. Galecki both said they did not understand any of the scientific dialogue in the show. Mr. Parsons said his last interaction with academic science had been when he flunked a course in meteorology at the University of Houston.

But then again, he added, they did not understand all the pop culture references to comic books and “Star Trek” any better. “What am I trying to say by saying this is the most important thing,” he said.

Mr. Galecki said: “A lot of people thought it would be a show that poked fun at smart people, but it has become a show that defends smart people much more often than that. These guys, as socially inept as they might be, are the type of people that are molding our future as a society.”

Mr. Parsons memorizes his lines by writing them out longhand and says he is astonished when people ask if the actors on the show ever improvise. “To veer away from the scripted dialog is a one-way trip to sudden death,” he said.

Still, problems and questions arise, which is where David Saltzberg, a particle physicist at the University of California, Los Angeles, and the show’s scientific consultant, comes in. Besides supplying the equations that appear on whiteboards in Sheldon and Leonard’s living room, he sometimes advises on the plotting and characters’ scientific predilections.

Dr. Saltzberg, who blogs about his activities on the show, said that many of the people who grouse to him about the show have not seen very much of it. His comments were echoed by Mr. Prady, one of the producers, who rejected the notion that the show stereotypes women. “Far from being a dumb blonde, Penny has demonstrated time and again that she possesses above average intelligence and practical knowledge that often far exceeds that of the guys,” he wrote in an e-mail message.

Indeed a perusal of the first two seasons turns up a wider variety of women in science than you might have thought, including Leslie Winkle, another Caltech physicist who seduces Leonard into a one-night stand and corrects an error on Sheldon’s whiteboard in the process.

The point of the show, Mr. Prady said, is to tell small stories. “We are not doing ‘Lost,’ we’re not doing a complex novel for TV,” he said. “We follow the characters, and let them tell us what they’re going to do next. We’re telling stories about outsiders. We all feel like outsiders. Can you find love? Penny pulls Leonard to the outside world; Sheldon pulls him back.”

Mr. Lorre said that the whole “challenge and joy” of a series like this is character development. “Maybe at the end of the day this will inspire some kids to go into physics,” he added, “just like ‘Cheers’ inspired countless young people to go into bars.”