Even a robot cricket always gets her mate

Edinburgh – Female crickets have an impressive knack for tracking down a mate. By listening for the “call songs” of the male – the familiar chirping sound we associate with crickets – the female moves almost unerringly toward her goal, ignoring other sounds and all obstacles in her path. Animal psychologists don’t follow quite as smooth a path, however. They run into an obstacle in the form of a question this behavior poses: Is the cricket making decisions about what she is doing, or is she just responding automatically to a stimulus?

Psychologist Barbara Webb of the University of Edinburgh, U.K., believes the apparently complex behavior is due to reflexive responses – that a relatively simple physical/neural mechanism is responsible for leading a female cricket toward the calling song of the closest male of her species. Webb has a lot of experience testing such theories using computer models, but that involves second-guessing the physics and idealizing the environment. “The equation you need to do sound propagation a complex environment are absolutely hideous,” she says. Instead, she decided to try something different: a robot. “The same problems occur in understanding perception in a robot and understanding perception in an animal,” says Webb. “They are encountering exactly the same difficulty of taking information from the environment, doing something with it, and then acting successfully at the other end?”

Webb’s unorthodox method proved to be inspired. Not only did she succeed in reproducing the cricketlike behavior she had predicted, but she also identified intriguing behaviors that were not programmed into the system, emerging only during testing. “She has really put forward a new hypothesis about how crickets might work…. Now biologists can go and start new experiments to test this,” says Holk Cruse, head of the Department of Biological Cybernetics at the University of Bielefeld in Germany.

Seeking a mate involves two different tasks for a cricket: identifying the right call song, then moving toward it. Webb’s theory is that a mechanism in the cricket allows her to recognize the song and simultaneously track its source. It is generally accepted among researchers that the position of a cricket’s two ears helps it distinguish louder and softer signals coming from each side. Each ear is halfway down one of the cricket’s front legs, and an acoustic channel links the ears through the legs and body. Sounds pass through the channel from one ear to the other so that the sound received at each ear can be compared and the loudest sound identified, giving the cricket directional guidance about the source of the sound. The cricket’s rigid body provides an inflexible channel to carry sounds, and this fixed acoustic system means the cricket’s hearing is sensitive to only one sound frequency – the song pitch of its own species.

But cricket song has many more variables than just pitch. The song is split up into “syllables” – short tones that repeat at regular intervals. Crickets emit these syllables in short bursts or “chirps.” How this structure helps a female cricket track down a mate has remained something of a mystery, but it was thought that the repetition rates of both syllables and chirps were important.

Webb speculated that the repetition of syllables provides the material for a “summing” procedure in the cricket’s brain. The intensity received by each ear is tallied during each syllable. After several syllables, the tally in one ear may reach a threshold, causing a set of neurons to begin firing, which causes the cricket to turn in the direction of the firing ear. The repetition rate of syllables is important because the summed tallies decay if they’re not reinforced: Too slow a repetition rate means the neurons would never reach the threshold; too high and both sets of neurons would be firing and the cricket would not know which way to turn.

Webb implemented this theory in a wheeled robot made from plastic building blocks with microphones for ears. The comparison of loudness by the two “ears” was carried out by a dedicated circuit, while electronic neurons took the signals from the microphones, summed the chirp data, and stopped the left or right wheel to make the robot turn. The robot was equipped with infrared and touch-bumper sensors so it could avoid obstacles.

When the call song of the right sort of male cricket was played through a loudspeaker, the robot was very successful at reaching it. Its movements were efficient, and they had many of the zig-zag characteristics of real cricket motion. When the syllabic structure of the song was changed, the robot became less efficient at finding the source, again consistent with cricket behavior.

While this was the behavior Webb hoped to find, she had not expected the robot to display other cricketlike behaviors. For example, when two identical complete songs were played through different speakers, the robot simply “chose” one speaker, almost as if it were the only one playing. When the song was split, however, with syllables being played alternately from each speaker, the robot – again like a cricket – would move to a point between the speaker before eventually choosing one.

Cruse believes that because the robot’s behavior so closely matches that of crickets, Webb’s work makes sense and her approach will point researchers in new directions. “[This shows] you can get complicated behavior based on quite simple reaction-based systems,” he says. But not everyone is so certain that this will tell us much about actual biological systems. Neurobiological behaviorist Ronald Hoy of Comell University in Ithaca, New York, for instance, says he believes Webb has made too many assumptions to be able to extrapolate to real crickets, and that there is room for more neural processing, or decision-making, than she allows. “I’m not sure that this is going to change the way I look at processing, although I’m certainly going to look at it more closely,” says Hoy.

Although Webb admits that the success of the robot model does not prove that the cricket uses the same perceptual mechanisms, it does at least show that it could. Despite “real-world” conditions – including noise, slipping motors, obstacles, and echoes – the robot cricket still gets her mate.

Business benefits of golf’s broad appeal: golf is a vital industry in Canada

According to an economic impact study commissioned by the National Allied Golf Associations (NAGA) in 2009, the game represents mort: than $11 billion in economic activity in Canada–more than both the forestry and film industries. It directly employs more than 155,000 Canadians and generates $7.6 billion in household income and close to half a billion dollars annually in charitable donations.

Direct benefit to all levels of government is significant as well. Golf contributes more than $3 billion in various tax revenues to federal, provincial and municipal coffers each year.

“Golf as an industry is vital to the economic well-being of hundreds of communities from coast to coast,” says Richard Janes, chairman of NAGA and commissioner and CEO of the Canadian Tour. “The size and scope of the industry is truly incredible.”

Driving this economic behemoth are more than six million Canadians who play golf. According to Jeff Calderwood, CEO of Canada’s National Golf Course Owners Association (NGCOA Canada), the game’s participation numbers are startling, considering the sport’s seasonality.

“There are more golfers in this country than there are hockey players,” Calderwood says. “That makes golf the number one sport in Canada, in terms of appeal and involvement. That’s a ‘great news’ story people all across this nation need to hear about.”


To offer some perspective on golf’s business scope and philanthropic reach, consider Canada’s greatest player.

Mike Weir has built his brand with a balance between charity and commercial opportunity. The 2003 Masters champion’s Canadian roots and humble persona make him an ideal endorser’, an athlete easy to relate to and recognizable among core golf and non-golf consumers. At the same time, his on-course and off-course success has allowed the eight-time PGA Tour winner to give back.

Weir and his wife Bricia started the Mike Weir Foundation in 2004 to advance the physical, emotional and educational welfare of children across Canada. Retail sales of Mike Weir Wine, an Ontario VQA product sold nationwide, is the foundation’s key monetary generator. The foundation also works in conjunction with a national partnership Weir has forged with the RBC Canadian Open for the Mike Weir Charity Classic; an affiliation with the Children’s Miracle Network and NGCOA Canada for the Mike Weir Miracle Drive for Kids; and a deal with Audi Canada, which established the Audi Best Buddies Challenge that Weir participated in.

It’s a philanthropic platform built on the marketing potential of the game of golf.

“We see the help the foundation gives to communities and hospitals we go to now,” Weir says. “That hits home with Bricia and me. To me, those things are way more rewarding than sinking a putt to win a tour” event.”

Is Bigger Better in Cricket?

The size of all organism’s genome–measured by the DNA content (C value) of egg and sperm–varies greatly among species (1). However, genome size does not correlate with the amount of genetic information that it contains or with the complexity of the organism (assessed by, for example, the number of different cell types) (2). This is called the C-value paradox and has puzzled biologists for decades. Now on page 1060 of this issue, Petrov et al. (3) present a possible solution to this paradox. The investigators provide evidence: to show that the long-term accumulation of excess noncoding DNA (and thus total genome size) differs among species owing to the differential rates at which this nonessential DNA is eliminated.

Among the smallest eukaryotic genomes are those of the yeast Saccharonyces cerevisiae (14 megabases (Mb)], the nematode Caenorhabditis elegans (100 Mb), and the fruit fly Drosophila melanogaster (165 to 180 Mb). Yet, the single-celled amoeba, one of the simplest of eukaryotic creatures, has an enormous genome worthy of a whale ([is greater than] 200,000 Mb) (3, 4). Plant genomes vary in size from 50 Mb for angiosperms (flowering plants) to 307,000 Mb for pteridophytes (ferns). In animals, genome sizes range from 49 Mb in sponges to 139,000 Mb in bony fishes (3, 4). The smallest vertebrate genome is that of the Japanese pufferfish, Fugu ruhripes (about 400 Mb) (4), whereas that of Homo sapiens (about 3000 Mb) is fairly typical of mammals (5).

Several mechanisms to explain the C-value paradox have been proposed. These include partial or complete duplication of the genome, genetic transposition (mobility of transposable elements), retroprocessed pseudogenes, replication slippage, unequal crossing over, and DNA amplification (4). Although larger genomes do not contain more genes than smaller genomes, they do contain more repetitive DNA (that is, sequences present in multiple copies) (5, 6). Retrotransposable elements (which move within the genome as RNA intermediates transcribed into DNA by reverse transcriptase) are one of the most abundant classes of repetitive DNA. These so-called retrotransposons are estimated to account for more than 50% of the total genome of maize (Zea mays) and the crucifer Arabidopsis thaliana (7). Of the 280 kb between the alcohol dehydrogenase and u22 genes in maize, about 60% is a jumbled mixture of retrotransposable elements (8).

From this kind of example, it is clear that genome size may increase because of multiplication of retrotransposable elements, but what is the long-term fate of this extra “junk” DNA? By investigating the fate of non-LTR (long terminal repeat) retrotransposable elements in the cricket Laupala and fruit fly Drosophila, Petrov and colleagues provide evidence for differing rates of “junk” DNA elimination. In an evolving genome, non-LTR elements are thought to proliferate by amplification of an extremely small number of “master” genes. These genes usually give rise to inactive copies (truncated at the 5′ end) that are incapable of further transposition within the genome (9). The defective copies arise because of their mode of transposition through reverse transcription (see the figure), which in most cases stops replication before the 5′ end is reached. These truncated elements, called DOA (“dead on arrival”), can be used as surrogates for pseudogenes in species such as Drosophila that have few bona fide pseudogenes (10).


Petrov et al. (3) examined multiple sequences of a LINE (long interspersed nuclear element) from 10 species of the Hawaiian cricket, which has a genome size about I 1 times that of Drosophila. They present a phylogenetic tree of DOA elements. The terminal branches of this tree show evidence of relaxed selection in the form of equal numbers of changes in all three codon positions across the coding region. (In coding regions of functional genes, the substitution rate of nucleotides in the third position of the codon is generally higher than in the first and second positions; in pseudogenes all codon positions have similar substitution rates.) Their key finding is that in Laupala the average rate of deletion per substituted nucleotide in the LINE is significantly lower, and the average size of deletions significantly smaller, than in Drosophila. This translates into a rate of DNA loss for the cricket that is 40-fold slower than that for the fruit fly. Consistent with its markedly bigger genome, the pattern of deletions in Laupala is more similar to that in mammals than to that in Drosophila, even though Laupala is an insect.

It will be interesting to see how widely the inverse correlation between deletion spectrum and genome size holds up across diverse taxa. In mammals there is already a suggestion that the deletion spectrum (as estimated from processed pseudogencs) may differ according to genome size (11). By using degenerate PCR primers to identify a non-LTR element in Laupala, Petrov et al. (3) provide an experimental approach that should be applicable to almost any group of organisms. At a deeper level, why should creatures such as Drosophila and Laupala show such differences in tolerance or permissiveness toward excess DNA? Do these variations reflect intrinsic differences in the mechanisms of DNA replication or other genomic processes, or is this an adaptive trait or just plain chance’? More information of the type provided by Petrov et al. as well as data from genome sequencing of diverse model organisms, should be useful in addressing these and related questions.


(1.) B. John and G. L. G. Miklos, The Eukaryotic Genome in Development and Evolution (Alien & Unwin, London, 1988).

(2.) M. J, Novacek and M. A. Norell, Trends Ecol. Evol. 4, 285 (1989).

(3.) D.A. Petrov et al., Science 287, 1060 (2000). 4. The Evolution of Genome Size, T. Cavalier-Smith, Ed. (Wiley, London, 1985), pp. 69-103.

(5.) W.-H. Li, Molecular Evolution (Sinauer, Sunderland, MA, 1997).

(6.) S. Brenner et al., Nature 366, 265 (1993).

(7.) P. Capy, C. Bazin, D. Higuet, T. Langin, Dynamics and Evolution of Transposable Elements (Landes Biosciences, Austin, TX, 1997).

(8.) P. SanMiguel et al., Science 274, 765 (1996).

(9.) P. L. Deininger et al., Trends Genet. 8, 307 (1992).

(10.) D. Petrov and D. L. Hartl, Gene 205, 279 (1997).

(11.) D. Graur, Y. Shuali, W.-H. Li, J. Mol. Evol. 28, 279 (1989).

(12.) T. Eickbush, New Biol. 4, 430 (1992). Molecules at Rest

The author is at the Laboratoire Populations, Genetique & Evolution, CNRS, 91198 Gif-sur-Yvette Cedes, France. E-mail: capy@pge.cnrs-gif.fr

A day of golf: the USGA museum reopens – Part 2

One of the speakers is Carol Semple Thompson, the greatest woman golfer of our time–greatest woman amateur golfer. She has won seven USGA championships. She describes herself as “the ultimate USGA brat”: Both of her parents were USGA officials. They had a rule in their family: All five kids had to play golf till they broke 90. Then they could quit. The only one who didn’t quit was Carol.

Today is Arnold Palmer Day, not just here in Far Hills, but in New Jersey at large. On hand to confirm this is Nancy Byrne, who’s the state’s executive director for travel and tourism. Charmingly and almost gigglingly, she says that this is her best day ever on the job. One can believe it.

There is lots and lots of Palmer hagiography–lots and lots of Arnie-worship. At least one speaker goes way over the top. There is a video too, honoring Palmer. Incidentally, the most engaging person on it–the best communicator–is President Bush (43). (His dad, 41, is honorary chairman of the USGA President’s Council.)

This day has been strangely Arnold-centric, and so is the remodeled and expanded USGA Museum. His name is on it, for goodness’ sake. Palmer is a great golfer, sure. But there have been many others: Jones, Nelson, Hogan; Nicklaus, Trevino, Watson. Palmer won a U.S. Am, a U.S. Open, and a U.S. Senior Open. Nicklaus won two, four, and two. Woods won three Ams (in a row), and (as of this writing) has won two Opens. Jones and Hogan won four Opens, Hale Irwin won three …

But statistics are beside the point: Should one man be so dominant at USGA headquarters, which should be sort of a national church of golf–above person, or at least a single person?

At any rate, Arnold is a big name and bursts with star power. He was key in the popularization of the game. And he has, it’s true, been particularly associated with the USGA. For example, he has done many television spots inviting golfers–hack and ace alike–to become USGA members.

He is the final speaker, and when he steps up to the mike, I feel almost sorry for him. He has been built up like crazy, and what can he say? But he rises to the occasion–in part by saying that he hardly deserves all this praise. He reads a stilted speech, stiltedly. But he soon puts down his text and looks at the audience: He says how flattered he is, and how much he appreciates the support of the USGA–particularly its nearly 1 million members.

And, except for the New Jersey lady, Arnold has been the briefest speaker of all.

He goes inside the museum, becoming, I suppose, the official first visitor. The museum is an excellent thing: tasteful, informative, and rich. I pause in the Bobby Jones Room, which has the man’s passport, law license, and other articles. And I pause at the World War II exhibit.

Among its items are golf balls made by American POWs. Golf has been played by our boys in conflicts all around the world–often in a makeshift way. It is ingrained in the American tradition. President Bush is refusing to play golf while we are at war: He thinks it’s unseemly for the commander-in-chief to be seen engaged in that pastime. A lot of us think this is deeply misguided–but the buck stops you-know-where.

Another exhibit highlights a couple of comebacks: one by Hogan, one by Babe Didrikson Zaharias. Hogan, of course, came back from a near-fatal car accident. Babe came back from cancer surgery–for a while (she died at 45). In 1954, she won the Open by twelve shots. If you will forgive a glib formulation, her caddie carried her golf clubs, and she carried a colostomy bag. What a woman.

Those of us who love golf history have a special home in Far Hills–we thrill to it. But the present’s not so bad either. Early in the day, a man who has been around golf for a while said to me–quite out of the blue–“Aren’t we lucky to live in the age of Tiger? Aren’t we lucky to be able to see him play?” We are. And we’re just lucky for golf, plain and simple.

Mr. Nordlinger is an NR senior editor. Here, There & Everywhere: Collected Writings of Jay Nordlingeris available at Store.NationalReview.com. There is a chapter on golf.


A day of golf: the USGA museum reopens – Part 1

Along the winding driveway, there are banners picturing golf greats. First Tiger Woods, then Annika Sorenstam (who has been, roughly, the Tiger Woods of the ladies’ tour). Then Jack Nicklaus, then Mickey Wright (nee Mary Kathryn). Then Gene Sarazen and Patty Berg.

So, they’ve gone boy-girl, boy-girl.

Who are “they”? The United States Golf Association, or the “USGA,” as everyone knows it. We are at their headquarters in remote, country New Jersey–it is “BYOOcolic,” as a friend of mine remarks. Today is the grand opening, or reopening, of the USGA Museum. It was closed for three years. And they’ve added an attractive wing, called the Arnold Palmer Center for Golf History.

Once upon a time, there was just “Golf House”–a stately Georgian home designed in the 1910s by John Russell Pope (of Jefferson Memorial and National Gallery fame). Now the USGA has a veritable compound. But it is the house that draws your eye. Among its pillars hang two banners, one of Bobby Jones, the other of Arnold Palmer.

The USGA Museum is sort of like the Smithsonian, which has been called “America’s attic.” The Smithsonian has Lindbergh’s plane and Archie Bunker’s chair; the golf museum has Jones’s putter and Ben Hogan’s 1-iron.

This is a perfect day for the reopening, with sparkling warm weather. “What is so rare as a day in June?” And, perhaps appropriately for June, the place looks set up for a wedding, with white tents and a chamber ensemble. (It is an all-brass group.) Everyone has a lovely time; everyone’s tickled to be here.

The USGA has a variety of responsibilities, among them the running of our national golf tournaments: the U.S. Amateur, the U.S. Open, etc. They also write and interpret the rules of golf–no, excuse me, the Rules of Golf. They do this in conjunction with the Royal and Ancient Golf Club in St. Andrews. And they test golf equipment, to make sure that these items–mainly clubs and balls–are in conformity with the rules.

A lot of us think that the equipment has gone crazy–that it has gone too far. (In the case of balls, literally.) But that is an argument for another day.

We visitors get tours of the Research and Test Center, where Iron Byron once reigned. “Iron Byron” was the name of the machine that tested balls–that swatted them. It was named after Byron Nelson, who had a remarkably consistent swing. A picture of an older Nelson, at the finish of his swing, graces a wall here. The new “Iron Byron” is computerized, and swings a lot faster. A technician taps a keyboard, and off it goes.

Out on the grounds, a crowd surrounds someone, and cameras flash. Must be Palmer–and, lo, it is. At 78, he is still a rock star, mobbed wherever he goes. The fans want autographs, and Palmer duly complies–he looks grim as he goes about this business. The fans are none too decorous, either: They are pushy, grabby, heedless. Was the autograph culture always this bad?

And here is another question: In the span of his career, has Arnold signed more autographs than he has hit golf balls? The numbers must be dizzying.

I think of Lynn Swann, whose race for governor of Pennsylvania I covered two years ago. He is a former football great (Pittsburgh Steelers). And, during the campaign, he had a rule: no autographs. And he was asked for them, constantly. I thought this was rather awkward, but he insisted that, if he started signing, he would not be able to move. He would be absolutely stuck.

I think back to this as Palmer is stuck.

Later, unstuck, he gives a press conference, at which he is asked about Tiger: Will the young champ be able to overcome his bum knee? Palmer says yes–he himself had a bum knee, and worked through it. Tiger should be able to march on.

Before long, it’s time for the ceremony–the official reopening ceremony. It’s held out on the lawn, in front of the house. Near the dais, a brass ensemble is playing a Purcell trumpet voluntary (as at a wedding). They also play some jazz and some patriotic music. Then comes a bagpipe band, as we must have, because golf comes from Scotland. They play–as they must–“Scotland the Brave.” It never fails to stir. And finally, we have our national anthem–hands go on hearts.


The emcee of the ceremony is Dottie Pepper, a former LPGA star and current TV commentator. She recalls an early Palmer book, subtitled “Hit It Hard!” This brings a chuckle from the audience, and from Arnold. In due course, a video is shown, featuring an assortment of champions. Someone in the video comments on Nicklaus’s supremacy. I look at Arnold’s face, which remains impassive. Nicklaus talk, he’s used to (or ought to be, by now).