evolution
stcynic | November 18, 2005An almost complete skeleton of a primitive mosasaur has been discovered and is reported in a geoscience journal this month. Mosasaurs were reptiles that moved back into the oceans and came to dominate shallow marine ecosystems between 65 million and 95 million or so years ago. The new fossil find still has its limbs intact, before they later evolved into flippers, indicating that it moved between land and sea. This was all prior to the mammalian species that moved back into the oceans, leading eventually to whales, dolphins and other marine mammals. For creationists, of course, this means…
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…
stcynic | November 2, 2005A year ago I had a fairly memorable exchange with Dean Esmay on the subject of evolution and creationism. He showed pretty clearly then that A) he doesn't have the first clue what evolution actually says and B) he has even less understanding of the dangers of creationism in public school science classrooms. So it's not a surprise that his latest salvo on the subject is so wide of the mark. Dean writes:
The courts did a tremendously stupid and destructive thing back in the 1980s when they banned so-called "creation science." The impression was made loud and clear to tens of millions of parents…
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 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…
loom | October 24, 2005Tomorrow I'll be giving a talk in Westport, Connecticut, based in part on my new book on human origins. I'll be talking about Hobbits, natural selection in our own time, and more (accompanied by visuals). The talk is part of the Westport Library's excellent lecture series. It will be at 7:30 and is free. Hope to see some readers of the Loom there.
loom | October 23, 2005You may have heard about a petition that was being signed by scientists earlier this month against the teaching of intelligent design. The inspiration came from another petition drafted by the Discovery Institute opposing evolution. It garnered 400 signatures of scientists in four years. R. Joe Brandon, an archaeologist, decided to see how many signatures he could get from scientists in just four days by spreading the word from his web site.
The answer: 7,733.
"During my short, four-day experiment, I recieved about 20 times as many signatures at a rate 690,000% higher than what the…
loom | October 16, 2005There was a time not that long ago when sequencing a single gene would be hailed as a scientific milestone. But then came a series of breakthroughs that sped up the process: clever ideas for how to cut up genes and rapidly identify the fragments, the design of robots that could do this work twenty-four hours a day, and powerful computers programmed to make sense of the results. Instead of single genes, entire genomes began to be sequenced. This year marks the tenth anniversary of the publication of the first complete draft of the entire genome of a free-living species (a nasty little microbe…
loom | October 15, 2005My post on the cognitive dissonance in Florida about evolution brought a lot of comments, including one from David. Although he seems to be attacking other commenters rather than post itself as far as I can tell, he makes three points that are worth addressing.
1. "...most of you have no clue as to what ID/Creationists really believe."
"ID/Creationists" is an interesting phrase, given how Intelligent Design advocates keep telling us over and over again that ID is not creationism. Are these ID folks lying?
2. According to David, "ID/creationists" see a difference "between mirco-evolution [sic…
stcynic | October 11, 2005Here is a great example, from the irreplacable Carl Zimmer, of how the theory of evolution helps to guide new research that may provide enormous benefit to us in understanding and combatting diseases that are based in genetic causes. Since I can't possibly express it any better than Zimmer, I'll let him do it:
Claes Wahlestedt, one of the scientists who will be setting up shop on Scripp's Florida campus, searches for new drugs by understanding how the human genome evolved. Genes only become active in our cells when certain proteins lock onto small stretches of DNA near them called enhancers.…
loom | October 11, 2005Finally: more bones.
Last October the world marveled at the announcement of the discovery of a new species of hominid, Homo floresiensis, in a cave called Liang Bua on the Indonesian island of Flores. One conclusion was more shocking than the next. First, this hominid stood only three feet high, earning it the nickname The Hobbit. Second, it lived as recently as 18,000 years ago, which was some 30,000 years after our own species had already been in southeast Asia for 30,000 years or more. The scientists argued that Homo floresiensis was a separate species that might have descended from Homo…
loom | October 10, 2005I've got a piece in tomorrow's New York Times on new research into the evolution of penguins. There's new work going on with penguin DNA and penguin fossils, such as this lovely 60-million-year old critter from New Zealand. It stood upright like living penguins, but still had wings it could bend at the elbow. In other words, just what you'd expect as flying ancestors evolved into full-blown penguins. While it's amusing to have a little fun with pundits who try to use penguins as role models for family values, writing about real science is always more satisfying.
(This picture is copyright the…
loom | October 10, 2005When it comes to evolution, the nation's attention is focused these days on Dover, Pennsylvania, where parents are suing the local board of education for introducing creationism into the classroom. It's certainly an important case, but if you really want to get a sense of what's at stake in the struggle over evolution, I suggest you turn your attention south, to the sunshine state. Florida is trying to have it both ways when it comes to creationism, and sooner or later something's going to have to give.
Two weeks ago, governor Jeb Bush broke ground on what he has called "a defining moment in…
loom | October 4, 2005In July Cardinal Christoph Schoenborn of Vienna wrote an eyebrow-raising op-ed in the New York Times that favored Intelligent Design over evolution. Now, as far as I can tell from this Reuters story, he's claiming he was misunderstood.
"Maybe one did not express oneself clearly enough or thoughts were not clear enough," he said. "Such misunderstandings can be cleared up."
Now he's saying that evolution's fine as long as biologists don't conclude that evolution proves there's no creator. Darwin's theory is "one of the very great works of intellectual history."
Compare this with his claim in…
loom | October 3, 2005
This year's Nobel Prize in medicine or physiology was announced this morning. Barry Marshall and J. Robin Warren won for discovering that ulcers can be caused not by stress or genes but by a bacterium called Helicobacter pylori (shown here). As my fellow Corantean, Derek Lowe, observes, this story follows the classic arc from, "You're completely bonkers" to "You're going to Stockholm." But it also illustrates a point that I made when last year's Nobelists were announced: it demonstrates how intimately woven evolutionary biology is becoming with medicine.
It turns out that Helicobacter…