loom | January 7, 2004Few humans have been as successful in Hollywood as parasitoids. Parasitoids are a particularly gruesome kind of parasite that invariably kills its host by the time it becomes an adult and is ready to leave the host's body. A parasitoid female wasp, to give one example, will fly along until it finds a caterpillar of some particular species. It lands on top of the caterpillar, jabs an egg-laying stinger into the caterpillar's body, and injects some eggs. The eggs hatch, the wasp larvae feed on the living caterpillar from within, and then, when they're ready to metamorphose into adults, they…
loom | January 4, 2004Today's issue of Newsday has my review of Sea of Glory, Nathaniel Philbrick's history of the first great scientific U.S. expedition. The review gets pretty harsh towards the end, despite the fact that the book is an exquisitely researched narrative of a fascinating subject. (What makes it particularly fascinating is that the expedition's leader, Charles Wilkes, was practically insane.) It's this very potential that got me so frustrated. Here's a grand story about a journey to the ends of the Earth, about megalomaniacs, about the dawn of a great nation, about the birth of modern science, about…
loom | January 2, 2004By sheer coincidence (or some journalistic twist of fate) two magazine articles of mine are coming out this week, and they just so happen to make a nice neurological pairing.
In Science, I've written an essay about what seventeenth-century natural philosophers have to teach twenty-first century neuroscientists about the brain. In the February issue of Popular Science, my cover story looks at the latest work on brain-machine interfaces that will let people control machines with thought alone. Inevitably, the Pop Sci piece can only focus on a time scale of a few years. But the latest brain-…
loom | December 30, 2003 They say that history is written by the winners, but if that's true, then natural history is written by those who can write. Our ancestors split from the ancestors of chimpanzees some 6 or 7 million years ago, and since then they've given rise to perhaps twenty known species of hominids (and potentially many more waiting to be discovered). Today only our own species survives, and only ours has acquired the intelligence to learn things about the distant past--such as the fact that we are the product of evolution. Our survival and our intelligence sometimes blur together, with the result that…
loom | December 24, 2003I can already see the grim look many Americans will have as they chew on their Christmas roast tomorrow. They'll be thinking about yesterday's report that a cow in Washington state tested positive for mad cow disease. There's some comfort in knowing that so far it's just a single cow, and that American cattle are regularly screened for bovine spongiform encephalitis. The grimmest look this Christmas may be on the faces of McDonald's shareholders and cattle ranchers. A single Canadian cow that test positive wreaked havoc on the entire beef industry up north. But this Christmas also brings a…
loom | December 22, 2003Evolution isn't simply about the genes you gain. It's also about the genes you lose.
The word loss has a painful, grieving sound to human ears, and so it can be hard to see how it can have anything to do with the rise of diversity and complexity in life. And until recently, evolutionary biologists didn't pay much attention to lost genes because they were preoccupied with the emergence of new ones. New genes, they found, can be produced in many ways. A gene can get accidentally duplicated, for example, and the copy can mutate, taking on a new function. Or pieces of two separate genes can get…
loom | December 18, 2003I will never figure out the publishing world. My new book, Soul Made Flesh officially publishes on January 6, 2004. But Amazon and Powell's both say they've got it now and can get it to customers in 1-2 days. I guess time isn't what it used to be.
I have put some early reviews on my web site. Booklist: "Remarkable." Kirkus Reviews: "Absorbing and thought-provoking." Publisher's Weekly: "Illuminating."
Reminder: seven days left till Christmas.
loom | December 18, 2003Just before the winter solstice brings autumn to an end, here's a chance to blog about the great evolutionary biologist--and student of fall foliage--William Hamilton. Hamilton, who died in 2000, has never reached the household-name status of other evolutionary biologists such as E.O. Wilson or Richard Dawkins or Stephen Jay Gould. But he deserves a place of privilege, for all his profoundly influential ideas. He found an explanation for altruistic behavior in many insect species by expanding biology's notion of fitness to include the genes an individual shares with its relatives. He offered…
loom | December 17, 2003Here's a new development in the search I described last week for the genes that make us uniquely human. Science's Michael Balter reports on a new study about a gene that's crucial for making big brains. Mutant versions of the gene produce people with tiny brains--about the size that Lucy had 3.5 million years ago. Comparisons of the human version of the gene with other mammals shows that it has undergone intense natural selection in our own lineage.
Size is far from everything, however. While humans have huge brains compared to other mammals, new kinds of wiring may have been more important…
loom | December 15, 2003Darwin's spirit lives on in everything from the Human Genome Project to medicine to conservation biology--the three topics I covered in my post on Friday. It also lives on in brain scans.
While Darwin is best known for The Origin of Species, he also wrote a lot of books in later years, most of which explored some aspect of nature that he showed revealed the workings of evolution. His examples ranged from orchids to peacock tails. In his 1872 book, The Expression of the Emotions in Man and Animals, he proposed that the expressions we humans use--our smiles, our frowns, and so on--are part of a…
loom | December 12, 2003To those who are new to my web log, thanks for checking it out. To those who have come from my old site, thanks for clicking through.
This week, while a sickly laptop robbed me of the opportunity to blog, a steady stream of interesting papers were published. Three struck me as particularly fascinating, because they illustrate the different ways evolutionary changes alter our world.
1. Scourges in waiting
When SARS failed to take hold in the United States, it was easy to feel smug about our defences against new epidemics. The nasty influenza strain now spreading across the United States…
loom | December 3, 2003In a post last month, I pointed out how aerospace engineers can learn a lot from looking at the fossils of ancient flying reptiles. Today's issue of Nature contains a variation on that theme: ancient swimming reptiles can teach geneticists a lot as well.
Almost all humans have five fingers. Genetic disorders can produce extra fingers and toes, but only rarely. Five fingers is generally the upper limit not just for humans, but for all vertebrates on land. You can find plenty of tetrapods whose ancestors lost one or more of those five fingers. Horses have just one; snakes none. But tetrapods…
loom | December 2, 2003Craig Venter has followed up on his announcement that he and his coworkers have assembled a virus from its genome sequence. Now there's a paper available at the Proceeding of the National Academy of Science web site. A bleary-eyed late-night inspection suggests that this is not a flawless Xerox machine for viruses; the researchers had to cast away lots of misassembled versions. (Still, they were able to isolate a perfect sequence in just two weeks.) More interestingly, the authors talk a bit about how they can use this same method to cobble together chunks of much bigger genomes to make…
loom | November 26, 2003Futurepundit has an interesting post based on a new paper about so-called junk DNA. Only 2% or so of the human genome actually encodes protein sequences. The rest is a grab-bag of broken genes and virus-like sequences called mobile elements that hijack the cell's DNA copying-machinery from time to time and insert new copies of themselves back into the genome. A pair of scientists have come up with some ideas about why organisms like us have junk-rich genomes, while bacteria have barely any. I was going to post on it until pre-Thanksgiving business overwhelmed me.
After summarizing this…
loom | November 24, 2003I'll be talking about evolution on Tuesday at 12 pm PST/3 pm EST with Alan Stahler on KVMR in California. You can listen to the live webcast here.
UPDATE: I'll be on at about 20 minutes after the hour. Andy Knoll from Harvard is on first.
loom | November 23, 2003It's too early yet for reviews of Soul Made Flesh to start rolling in (it pubs in January 2004), so I'm still in an anxious state. But this is promising: The Daily Telegraph in London asked several leading writers to name the favorite book they read in 2003. Yesterday it printed the results. Steven Pinker chose Soul Made Flesh.
He writes: "Today the idea that every aspect of human experience consists of activity in the brain is second nature to some people, and an 'astonishing hypothesis'- or even sacrilege - to others. But few are aware of the ancestry of this idea. Soul Made Flesh tells…
loom | November 19, 2003Texas may be off the hook for now, but Razib at Gene Expression observes that some medical students at the University of Oslo are lobbying for anti-evolution lectures. I guess I'll try not to be in Norway if I need antibiotics.
loom | November 18, 2003For everyone interested in how their brain works, I'd suggest checking out a book coming out soon called Picturing Personhood, by MIT anthropologist Joseph Dumit. Dumit shows how easy it is for brain scans to become cultural Rorschach tests. Scans of mental activity, such as fMRI or PET, are basically complex graphs that represent the relationships of data gathered in very narrowly defined experiments and which are then statistically massaged with special-purpose software. But for most of us non-scientists (and even some scientists) it's easy to look at these images as objective snapshots of…
loom | November 13, 2003The case of Terri Schiavo has moved back into the Bleak House realm of endless trips to the courthouse. As I mentioned in an earlier post, Schiavo lost consciousness thirteen years ago, and her husband has been trying for the past few years to have her feeding tube removed over the objections of her parents. The Florida legislature recently passed a law that gave Governor Jeb Bush the authority to order Schiavo's tube put back in, and now her husband is going to court to challenge the constitutionality of the law.
The frenzy of editorials and TV interviews is beginning to subside, but only a…