Blogs / The Loom

I will be on the public radio show The Takeaway at 720 am EST Tuesday to talk about fireflies. I’ll update this post with a link to the podcast when it’s online. [And here it is.]

Fireflies are the topic of my story on the cover of the New York Times science section tomorrow. It’s the result of a visit I paid last Friday evening to a meadow in Massachusetts, where I listened to Sara Lewis of Tufts University explain the sultry, complex tale of sex, deception, and death that was playing out in front of me.

I first got to know Lewis’s work last summer, when I decided I wanted to include fireflies in my next book, The Tangled Bank: An Introduction to Evolution. Lewis co-authored a fascinating review of firefly biology last year (free pdf from Lewis’s web site). I particularly liked this chart, which shows how different species have evolved different flash signals.

The male, flying around, releases a certain pattern of flashes–a single one second pulse followed by a five secondin the case of Photinus pyralis, for one example. And if a female P. pyralis, sitting on a blade of grass, likes what she sees, she responds three seconds later. Not one. Not six. Three. If she responds at the right interval, he knows he’s found a female of his own species and zeroes in, sending more flashes. She may also be signalling other males at the same time; which male she chooses may come down to subtle features of the flash pattern–for example, a rapid series of pulses as opposed to a slow one.

You can, as I discovered, speak their language with a penlight. You can even play the male or the female, depending on your mood.

There’s lots of strange business going on out among the fireflies. I didn’t have room in the article to describe some of Lewis’s new areas of research. Because female fireflies mate with several males, they can end up with sperm from several males inside them at once. Studies on other animals have suggested that females can choose which male’s sperm they’ll use to fertilize their eggs. Males can also inject chemicals with their sperm that increase their odds of fertilization. It’s clear that in many species, female preferences and male competition can continue after mating ends.

No one knows how this struggle plays out in fireflies. Adam South, one of Dr. Lewis’s graduate students, is investigating this side of the evolutionary equation. He is mating female fireflies with two males apiece and then collecting the eggs they lay. Using DNA tests, he’s determining the paternity of the eggs. Perhaps the males with more attractive flashes have more offspring.

What scientists like Lewis know about fireflies is remarkable, but it’s dwarfed by what they don’t know. Are fireflies on the decline, for example? Unfortunately, there’s no good long-term data. But that’s now an opportunity for some citizen-science you can get involved in. Lewis and some former students have helped organize Firefly Watch, based at the Boston Museum of Science. You can make your backyard part of biology’s new frontier.

As a science writer, I often find it sobering to read scientific history. Science works slowly, even though we wish it would work in nanosecond breakthroughs.

In 1913, for example, a Russian scientist named Nikolai Anichkov ran an experiment in which he had egg yolks fed to rabbits. On this cholesterol-heavy diet the rabbits developed atherosclerosis. The more cholesterol the rabbits ate, the bigger the deposits on their blood vessels became. It was a tremendous discovery, considered by some one of the greatest in medical history.

But it did not lead overnight to a treatment for heart disease. In fact, it did not even lead, on its own, to a clear understanding of how cholesterol ends up in the blood vessels. Instead, it focused the attention of later scientists on the question of cholesterol. It took many years for scientists to figure out the steps by which enzymes produce cholesterol molecules. Then scientists began searching for drugs that might interfere with those enzymes.

In 1971, six decades after Anichkov ran his egg-yolk experiments, Akira Endo of Tokyo Noko University and his colleagues, decided to see if microbes made natural cholesterol-fighting compounds (free pdf). They reasoned that such a compound would be a potent weapon against microbial competitors, since cholesterol and related molecules are essential for building cells. In 1973 they found a fungus that blocks a key enzyme in the cholesterol pathway. It took more than another decade before drugs based on Endo’s explorations, known as statins, reached the market. Today drugs like Lipitor are prescribed to millions of people.

If a journalist wrote an article on Anchikov’s intial research, the most accurate headline would have been something like: “RUSSIAN SCIENTIST DISCOVERS LINK BETWEEN MOLECULE AND HEART DISEASE. WILL LEAD TO POWERFUL NEW MEDICINE IN EIGHTY YEARS.”

Of course, it would be a rare journalist who would be able to see eighty years in the future like that. And headlines about events readers won’t be alive to see can seem awfully remote. Anchikov’s discovery did not change the lives of the people who could have read about it at the time. Their grandchildren, yes.

I’ve been thinking about Anchikov recently, after having read a letter to the New England Journal of Medicine. It’s by Joel Hirschhorn of Harvard, on the subject of genomes.

A decade ago a complete sequence of the human genome was still a dream, although a dream close to becoming real. In a typical article from 1999, a reporter wrote that “scientists hope to treat diseases in much the same way that software engineers fix faulty computer programs, by isolating flaws in the code.” Once we could read the entire human genome, the article promised, nothing would be the same: “By identifying the genetic roots of illnesses like cancer and heart disease, some experts say, the science of the genome, or genomics, may make it possible for a child born today to live to 150–or, some say, much longer.”

What a difference a decade makes. Scientists have been finding many genetic markers for common diseases like heart disease and diabetes, but they’re not pointing the way to obvious treatments. The falling cost of DNA is letting scientists sequence genomes left and right–not just people’s genomes, but the genomes of their cancer cells and their microbes. And for now, scientists are drowning in data rather than plucking out new cures.

Hirschhorn wants the growing number of skeptics to keep history in mind. In his NEJM letter he writes,

New biologic insights do not guarantee a rapid translation into clinical practice; the latter will require great effort by basic, translational, and clinical researchers. The difficulty in translation is not unique to genetic discoveries: nearly a century and three Nobel Prizes separate the determination of the chemical composition of cholesterol from the development of statins. Each discovery of a biologically relevant locus is a potential first step in a translational journey, and some journeys will be shorter than others. With a more complete collection of relevant genes and pathways, we can hope to shorten the interval between biologic knowledge and improved patient care. 

In the next issue of Newsweek, I consider the near-term and the long-term future of genomes. My essay is called “The Gene Puzzle.” Check it out.

[Animation: Wikipedia]

Over at the Origins blog on Science’s web site, I take a look at what means to have sex–especially if you happen to be bacteria. Check it out.

I wrote about the two sides of our brains in April for Discover. Now some of the scientists whose research I highlighted have an article of their own in Scientific American, focusing on the ancient evolutionary origins of specializations in each hemisphere. So if you still have interhemispheric cravings, check it out!

Mind wandering is the subject of my new column for Discover. Far from just useless mental static, mind-wandering actually creates a distinctive pattern of activity in our brains–a pattern that suggests that it may actually be playing a crucial role in our mental life. Check it out.

Here’s a vision of how science may work in the future.

Last month I scrambled to write a story about the evolution of swine flu for the New York Times. I talked to some of the top experts on the evolution of viruses who were, at that very moment, analyzing the genetic material in samples of the virus isolated around the world. One scientist, whom I reached at home, said, “Sure, I’ve got a little time. I’m just making some coffee while my computer crunches some swine flu. What’s up?”

All of the scientists were completely open with me. They didn’t wave me off because they had to wait until their results were published in a big journal. In fact, they were open with the whole world, posting all their results in real-time on a wiki. So everyone who wanted to peruse their analysis could see how it developed as more data emerged and as they used different methods to analyze it.

Now, a little over a month later, they’re publishing their results in the journal Nature. Normally we press folks would get a press release about the paper a week before publication, and it would be under strict embargo till it appeared in the journal. This morning, however, I got a press release pointing me to the published paper. And while Nature normally requires you to subscribe to read a paper, the flu paper is published under a Creative Commons license, which means anyone can get it and use it under the license’s terms.

While that’s all very exciting, the paper itself is an anxiety-triggering read. The new swine flu (which the authors now call S-IOV S-OIV) is only distantly related to other known swine flus, which means that there are a lot of flu viruses circulating around about which we know very little. And, as I mentioned in my article, it had already entered the human population several months before it came to light earlier this spring. Be sure to check out figure 1 (I’m inserting it below from the wiki–thanks, Creative Commons!), which shows how lots of bird, swine, and human season flu viruses mixed together to produce the new beast. The authors warn that the pattern of evolution they see is the sort of pattern the big flu pandemics followed when they emerged in the past.

With this sort of urgent situation at hand, the patient process of old-fashioned science publishing may have to be upgraded.

[Image: CDC]

Yesterday, I wrote about how snakes use their scales to help them crawl without legs. But what if you don’t have bones–what if you’re just a single cell? I’ve always been fascinated by how cells crawl about, like minuscule versions of The Blob. I recently had an excellent time talking to some of the scientists who are figure out what goes on inside cells when they go from point A to point B. And that’s the subject of my article in today’s New York Times. Be sure to check out the video and graphics that go along with it. It’s alive!

[Image: Wikipedia]

“We do not even in the least know the final cause of sexuality; why new beings should be produced by the union of the two sexual elements…The whole subject is as yet hidden in darkness.”

So wrote Charles Darwin in 1862. In this week’s issue of Science, I write an essay on what we know now about this mystery. The essay is here (subscription required), and you can listen to me talking about why sex is weirder than you know on this week’s Science Podcast.

To continue this celebration of sex in all its evolutionary glory, I’ll be guest-blogging a few times this month over at Science’s Origins blog. I’ll let you know here when each post goes up.

Image: From Robert F. on Flickr/Creative Commons Licence

Readers of the Loom may be familiar with the work of Bryan Fry, who studies the evolution of snake venom. (See these two previous posts on his work.) I’ve got an article in tomorrow’s New York Times about his latest paper, to be published this week in the Proceedings of the National Academy of Sciences. In it, Fry and a big team of collaborators argue that Komodo dragons, the biggest lizards on Earth, are venomous. (There wasn’t room in the story to describe their argument that an extinct relative of Komodos that measured 21 feet long, was venomous too.) Provocative stuff, to be sure, and certainly not universally embraced by other researchers. I got some highly spicy quotes from critics. Check it out.

(PS: When the paper is put online this week, you’ll be able find it here: http://www.pnas.org/lookup/doi/10.1073/pnas.0810883106 )

[Image from Wikipedia]

This year marks the fortieth anniversary of the publication of Philip Roth’s novel Portnoy’s Complaint. In 1969, the book also became fodder for one of the oddest ideas in neuroscience: the grandmother cell. What if a neuron in your head only responded to the sight of your grandmother? For a long time, many neuroscientists have dismissed it out of hand. And yet the idea will not quite die.

Earlier this year a psychologist published an intriguing review of the grandmother cell, arguing that we should not be so hasty to run its obituary. Other scientists I’ve spoken to don’t think grandmother cells actually exist, but their own ideas about how we recognize individuals are equally fascinating. I’ve put together what I’ve learned about Philip Roth’s unexpected contribution to neuroscience in my latest Brain column for Discover. You can read it here.

Should I take it as a compliment that somebody took the time to hack my online archive of articles? It’s still pretty irritating. Whatever the twisted motivations of the hacker, my web guardians and I are now figuring out how to repair the mess. My apologies to anyone seeking an article.