loom | May 10, 2005Blogging will be light for a few days because my hard drive devoured itself last night. I just wanted to mention a couple brain-related items. First off, I've got a profile in today's New York Times of Michael Gazzaniga, one of the most fascinating people involved in science today. His research on the split minds of people with split brains would be fascinating enough, but now he's trying to use these insights to make sense of the confusing choices that bioethics now forces us to make. (Gazzaniga's a feisty member of the President's Council on Bioethics.)
For another take on the brain and our…
loom | May 4, 2005Judging from fossils and studies on DNA, the common ancestor of humans, chimpanzees, and bonobos lived roughly six million years ago. Hominids inherited the genome of that ancestor, and over time it evolved into the human genome. A major force driving that change was natural selection: a mutant gene that allowed hominids to produce more descendants than other versions of the gene became more common over time. Now that scientists can compare the genomes of humans, chimpanzees, mice, and other animals, they can pinpoint some of the genes that underwent particularly strong natural selection…
loom | May 2, 2005Evolutionary psychologists argue that we can understand the workings of the human mind by investigating how it evolved. Much of their research focuses on the past two million years of hominid evolution, during which our ancestors lived in small bands, eating meat they either scavenged or hunted as well as tubers and other plants they gathered. Living for so long in this arrangement, certain ways of thinking may have been favored by natural selection. Evolutionary psychologists believe that a lot of puzzling features of the human mind make sense if we keep our heritage in mind.
The classic…
loom | May 1, 2005On Thursday I predicted that pundits would make the rediscovery of the Ivory-billed woodpecker an opportunity to criticise predictions that humans are causing mass extinctions--while conveniently ignoring evidence that goes against their claims. Today I came across the first case I know of, which appears a short Week-in-Review piece about the woodpeckers in the New York Times. (You have to scroll down a bit to the article.)
First, a conservation biologist is quoted saying that most things that scientists think are extinct are extinct. The article then ends with this:
But Stephen Budiansky,…
loom | April 30, 2005Thanks to the various readers who have noticed the creationist Google ads that pop up on some of the Loom's pages. Such are the hazards of letting robots handle ads. I will talk with the good people at Corante about this.
loom | April 29, 2005
The feud over Homo floresiensis, the little people of Indonesia, centers on whether they were an extinct diminutive species that evolved from some ancient hominid, such as Homo erectus, or whether they were just pygmy humans, perhaps suffering from some disease. The leading skeptic, paleoanthropologist Teuku Jacob, has claimed that there are pygmies living not far from where the fossils were found, on the island of Flores. I came across a short item at Japan Today about a scientific expedition to study the pygmies, which was based on an article in Kompas, an Indonesian publication. The…
loom | April 28, 2005From time to time, scientists discover that a species that was once thought to have become extinct is actually surviving in some remote place. If the species is a salamander or a lemur, it gets a quick headline and then promptly goes back to its obscure, tenuous existence. But here's one rediscovered creature that I suspect will get some major press: the Ivory-billed woodpecker is back. Science is publishing a paper in which scientists report several sightings and a video of the magnificent bird, which hadn't been seen since in the United States since 1944. Here is a report from the AP.
The…
loom | April 25, 2005In the new issue of Smithsonian, I've got an article about life on Mars. I'm not writing about anything NASA has actually found, but instead about the difficulty of just recognizing life, even if the evidence is in your hand (or in your rover's spectrometer). While the chances of life existing today on the surface of Mars aren't fantastic, a lot of researchers are pretty optimistic that there are fossils to be found. But it turns out that fossils of microbes are even more difficult to identify. You just need to consider some of the fierce debates over some of the oldest fossils on Earth--a…
loom | April 13, 2005This morning the New York Times reported that the National Geographic Society has launched the Genographic Project, which will collect DNA in order to reconstruct the past 100,000 years of human history.
I proceeded to shoot a good hour nosing around the site. The single best thing about it is an interactive map that allows you to trace the spread of humans across the world, based on studies on genetic markers. I'm working on a book about human evolution (more details to come), and I've gotten a blinding headache trying to keep studies on Y-chromosome markers in Ethiopian populations and…
loom | April 12, 2005I have a weakness common to many bloggers--I like to check my site meter to see who's coming to my blog, and from where. Often I wind up discovering intriguing sites run by people whose interests run along the same lines as mine, such as evolutionary biology. Today, however I was surprised to see a lot of traffic coming from Answers in Genesis, a creationist web site.
First off, greetings to all visitors who come through the link. I hope you find some interesting things here.
I decided to investigate the source of the link, and the results were interesting. It turns out that today Answers in…
loom | April 12, 2005I've been catching up on my online reading, and a couple days ago John Hawks offered this tantalizing hint that Homo floresiensis a k a the Hobbit may be a pathological specimen. Such claims have been made before based on the small skull of the hominid, but they've been pretty powerfully rebutted. But Hawks is claiming that the rest of the skeleton is sickly. He seems to be basing this contention on having seen the bones, and on research by others that will be coming out soon. Now, normally I wouldn't put much stock in this sort of off-hand remark, but Hawks has been so good on his blog that…
loom | April 11, 2005I've got an article in tomorrow's New York Times about a startling new way to control the nervous system of animals. Scientists at Yale have genetically engineered flies with neurons that grow light-sensitive triggers. Shine a UV laser at the flies, and the neurons switch on. In one experiment, the scientists were able to make decapitated flies leap into the air by triggering escape-response neurons. In another, they put the trigger in dopamine-producing neurons, and the flash sent healthy flies walking madly around their dish. (You can read the paper for free at Cell's web site.)
In working…
loom | April 6, 2005Two of the most important stages in hominid evolution were the origin of the entire hominid branch some six to seven million years ago and the first movement of hominids out of their African birthplace. This week we now get a new look at both.
On the cover of Nature, the editors splashed the first reconstruction of Sahelanthropus, the oldest known hominid. The scientists who made the reconstruction used new material they found in the Sahara, adding to the material they described in their first report in 2002. There had been some argument over whether Sahelanthropus was an early hominid that…
loom | April 4, 2005I'm guessing it's only a matter of time before this guy gets a show on cable. Bryan Fry is a biologist at the University of Melbourne in Australia, and he spends a lot of his time doing this sort of thing--messing with animals you really really shouldn't mess with. In addition to being telegenic, he rattles off those delicious Australian phrases, like, "No drama, mate." (Translation: No problem.)
While Fry is comfortable milking a king cobra in a jungle, he also has a lab-jockey side, using genomic technology to dredge up vast numbers of new snake venom genes. In tomorrow's issue of the New…
loom | March 30, 2005Spring is finally slinking into the northeast, and the backyard wildlife here is shaking off the winter torpor. Our oldest daughter, Charlotte, is now old enough to be curious about this biological exuberence. She likes to tell stories about little subterranean families of earthworm mommies and grub daddies, cram grapes in her cheeks in imitation of the chipmunks, and ask again and again about where the birds spend Christmas. This is, of course, hog heaven for a geeky science-writer father like myself, but there is one subject that I hope she doesn't ask me about: how the garden snails have…
loom | March 28, 2005I'll be a guest tonight at 7 PM EST on NPR's talk show On Point, talking about the new wave of dinosaur science. Jack Horner will be on as well, delivering the dirt about his mind-blowing discovery of soft tissue from a T. rex. Should be interesting.
Update, 3/29/05 9:30 am: The show is now archived here. The links to the real player and windows media feeds are at the top of the page.
loom | March 23, 2005Today Gregor Mendel is a towering hero of biology, and yet during his own lifetime his ideas about heredity were greeted with deafening silence. In hindsight, it's easy to blame his obscurity on his peers, and to say that they were simply unable to grasp his discoveries. But that's not entirely true. Mendel got his ideas about heredity by experimenting on pea plants. If he crossed a plant with wrinkled peas with one with smooth peas, for example, the next generation produced only smooth peas. But when Mendel bred the hybrids, some of the following generation produced wrinkled peas again.…
loom | March 21, 2005Panda's Thumb has an update on the ongoing drama over teaching creationism in public schools taking place in York, Pennsylvania. Last year a group of residents donated 58 copies of a creationst book called Of Pandas and People to the local school. The board of education reviewed them and gave them the green light. The books are now available in the school library.
Now someone has donated 23 science books, many of which deal with evolutionary biology, to see how the board deals with them. So far, the board has said it will review them as to their "educational appropriateness," and has left it…
loom | March 21, 2005Readers were busy this weekend, posting over fifty comments to my last post about HIV. Much of the discussion was sparked by the comments of a young-Earth creationist who claims that the evolutionary tree I presented was merely an example of microevolution, which--apparently--creationists have no trouble with. This claim, which has been around for a long time, holds that God created different "kinds" of plants and animals (and viruses, I guess), and since then these kinds have undergone minor changes, but have never become another "kind."
Some readers expressed frustration that the comments…
loom | March 18, 2005You may have heard last month's news about an aggressive form of HIV that had public health officials in New York scared out of their professional gourds. They isolated the virus from a single man, and reported that it was resistant to anti-HIV drugs and drove its victim into full-blown AIDS in a manner of months, rather than the normal period of a few years. Skeptics wondered whether all the hoopla was necessary or useful. The virus might not turn out to be all that unusual, some said; perhaps the man's immune system had some peculiar twist that gave the course of his disease such a…