loom | December 6, 2005Over the weekend I was part of a panel at the American Anthropology Association, the topic of which was "Updating Human Evolution." I got to listen to ten presentations by scientists, each offering a look at how our understanding of our ancestry is changing with new research. While they were all interesting, I was particularly eager to hear one: Alan Templeton of Washington University. Templeton. Having just finished a book about human evolution, I knew that Templeton has been doing some groundbreaking work to figure out what our DNA has to say about our evolutionary history. I was looking…
loom | December 1, 2005I've been asked to review a couple books about global warming. Climate change and evolution, which I mainly write about, are intimately related, since life is a potent source of greenhouse gases (methane from bacteria, etc.) and abrupt climate change has triggered profound changes in the biosphere. This assignment has me taking a particularly close look to all the new research and political news emerging these days.
And I'm getting a funny sense of deja vu.
Those who pay close attention to the work of creationists know that they have a penchant for quote mining--for snipping out a passage…
loom | December 1, 2005Light blogging this week is due to my frantic fragment of a week, returning from Thanksgiving and preparing to head down to DC to participate on a panel at the American Anthropological Association. The panel is called "Updating Human Evolution: Bringing Anthropological and Public Coneceptions into Contemporary Perspective," and will take place Saturday afternoon starting at 1:45 pm. Ten anthropologists are going to talk about new advances in our understanding of human evolution, from humans as prey to the evolution of the sexes. (You can find the full line up here. Search the pdf for the…
loom | November 29, 2005Writing about paleontology without illustrations is like directing a movie without a camera. When I wrote my first book, At the Water's Edge, I had the good fortune to join forces with Carl Buell, who brought walking whales and fish with fingers to life. Now he has come to the other side, with a blog of his own, complete with pictures. Check it out.
loom | November 28, 2005I've got a short piece in tomorrow's New York Times about the 400-million year history of insects. Some beautiful pictures of the creepers included.
loom | November 28, 2005Getting back home from a Thanksgiving journey full of turkey and queasy toddlers on airplanes, I just noticed that my visit-counter has rolled past the 500,000 mark. I never would have dreamed of such figures when I started this blog, and I just want to take a second to thank everyone who has ever clicked their way to the Loom.
loom | November 27, 2005Natural selection is not natural perfection. Time and again, biologists have discovered traits that are both beneficial and harmful. Perhaps the most famous example is the devastating disorder known as sickle-cell anemia. To get sickle-cell anemia, you have to inherit two faulty copies of a gene that helps build hemoglobin, the molecule that traps oxygen in red blood cells. In this condition, hemoglobin can't hold its shape if it's not clamped around oxygen. Without it, the defective hemoglobin collapses into needle-shaped clumps, which then turn the cell itself into a sickle shape. The…
loom | November 21, 2005Back in February I discovered the remarkable work of Australian biologist Bryan Grieg Fry, who has been tracing the evolution of venom. As I wrote in the New York Times, he searched the genomes of snakes for venom genes. He discovered that even non-venomous snakes produce venom. By drawing an evolutionary tree of the venom genes, Fry showed that the common ancestor of living snakes had several kinds of venom, which had evolved through accidental "borrowing" of proteins produced in other parts of the body. Later, these genes duplicated to create a sophisticated cocktail of venoms--a cocktail…
loom | November 18, 2005Following up on my earlier post, I wanted to relay one more piece of book news. I've been getting some emails over the past couple months inquiring about my book, Evolution: The Triumph of an Idea. I wrote it as a companion volume to the 2001 PBS television series, Evolution. Like the series, the book surveys the history and cutting edge of evolutionary biology, from the origin of new species to mass extinctions, from the rise of complex life to the emergence of humans. It also looks at ongoing evolutionary races, whether the competitors are hosts and parasites or members of the opposite sex…
loom | November 17, 2005My latest book, Smithsonian Intimate Guide to Human Origins is now available on Amazon.com, and I think it's getting put on the shelves at bookstores. I've only referred to the book here glancingly from time to time, and I wanted to take a minute now to give Loom readers a sense of the book (and perhaps inspire the sales of a few copies).
From the start of this blog, I've dedicated a lot of space to new discoveries about where we came from. I've written about spectacular new fossils, from Sahelanthropus, the oldest known hominid to the Hobbits (a k a Homo floresiensis), which might have been…
loom | November 14, 2005This story starts in 1987, with the skin of a frog.
Michael Zasloff, a scientist then at NIH, was impressed by how well a frog in his lab recovered from an incision he had made in its skin during an experiment. He kept his frogs in a tank that must have been rife with bacteria that should have turned the incision into a deadly maw of infection. Zasloff wondered if something in the skin of the frog was blocking the bacteria. After months of searching, he found it. The frogs produced an antibiotic radically unlike the sort that doctors prescribed their patients.
Most antibiotics kill bacteria…
loom | November 7, 2005As a father of two dawn-loving children I don't get as much sleep as I used to, which makes me wonder sometimes why I crave it so much. A number of scientists who share my curiosity have turned to sleeping animals to find an answer. Sleep appears to be an ancient behavior, perhaps 600 million years old or older. But it may not exist "for" any one purpose. Instead, sleep can serve many functions, as animals are shaped by evolutionary tradeoffs. I've written an article about the evolution of sleep for tomorrow's New York Times where you can read more. (And for those interested in some of the…
loom | November 5, 2005The insects scandalously embracing in this picture are decorated crickets (Grylllodes sigillatus), which can be found in the southwestern United States, among other places. The droplet on the male's tail is--for want of a better word--a gift. After producing this glob he sticks it onto the package of sperm he places on the female. After the crickets are finished with their encounter, the female will grab the gift and snack on it.
In an age when penguins can become role models for traditional family values, some people may be tempted to celebrate the decorated cricket as everything a gentleman…
loom | November 3, 2005Back in March I described a provocative paper that suggested that plants might be able to get around Mendel's laws of heredity. Reed Cartwright, the grad student behind De Rerum Natura, left a comment expressing some deep skepticism. Now he reports that he and Luca Comai of the University of Washington have published a letter in the journal Plant Cell. You can read the letter for free. (There's another paper commenting on it in the journal, but it requires a subscription.)
In the original experiment, scientists bred plants, noting which version of a gene called hothead got passed down to new…
loom | October 30, 2005A new autumn has brought another burst of red and yellow leaves. And it has also brought an interesting new idea about why trees put on this show every year.
In recent years, scientists have been roughly divided into two camps when it comes to autumn leaves. One camp holds that autumn colors are just part of preparations for winter. The other holds that the colors are a warning to insects to stay away.
The warning hypothesis came from the late biologist William Hamilton. He pointed out that trees fight off insect larvae with toxins. A more vigorous tree could produce more toxins than a…
loom | October 28, 2005Peter Brown, anthropologist on the hobbit team, jumps into the comment fray himself on the nature of the fossils he discovered.
loom | October 28, 2005I'll be talking to science writers about blogging on Tuesday in New York. If you'd like to participate in the discussion, leave your comments here. Thanks.
loom | October 27, 2005A Bronx cheer for the four-legged hobbit from one of its discoverers. See my updated post.
loom | October 27, 2005Well, here's an idea I haven't heard of before...
Last year scientists found the bones of what they recognized as a new species of hominid that lived as recently as 12,000 years ago. They named it Homo floresiensis, and its three foot stature earned it the nickname the Hobbit. All of the reconstructions I've seen until now have shown the Hobbit standing upright--which you might expect of a hominid that descended from upright ancestors (perhaps Homo erectus or even the more primitive Australopithecus).
But in the November issue of the Dutch science magazine Natuurwetenschap & Techniek,…
loom | October 26, 2005There have been some interesting new developments in the study of the evolution of language. The idea that human language emerged from hand gestures rather than sounds has been getting very popular in recent years. Some scientists think that certain neurons in the brain played a crucial role in this gestural prehistory. Known as mirror neurons, they simulate the movement of other people's hands, among other things. In the October 14 issue of Science, a team of scientists showed that mirror neurons are even more sophisticated than previously thought. They even speculate that some mirror…