Posted by PvM on June 26, 2004 | Comments (3) | TrackBack (0)

In addition to my reviews and evaluation of the Privileged Planet ideas, the book has now been reviewed in Nature by Douglas A. Vakoch from the SETI Institute. Titled “Bright blue dot” NATURE VOL 429 24 JUNE 2004 p 808-809

Continue reading  “Privileged Planet: Nature review”

Posted by Ed Brayton on June 26, 2004 | Comments (78) | TrackBack (0)

Ed Note: This is a guest column written by Sean Starcher and JA Pourtless. You can read the original version of this column on Sean’s blog.

Casey Luskin of the IDEA Center has really had it piled on lately. We don’t want it to seem like we’re picking on him (there are certainly a healthy number of creationist websites out there that are in serious need of a reality check!), but his primer on “Problems with Evolutionary Explanations of the Fossil Record” contains some serious errors that are in immediate need of correcting.

That there are “some” errors is a bit of an understatement, but for the time being we’re going to focus in on two of his major criticisms. He says:

But what did Archaeopteryx come from? Given the similarities to therapod [sic] dinosaurs, it is usually claimed to be a nice clean relative of the therapods [sic]. The catch? These therapods [sic] are only known from one locality—the Yixian formation in China, and according to the radiometric dates, the Therapods [sic] are “at least 20 Myr younger than Archaopteryx” [sic]. To give an analogy, that’s sort of like saying that the first apes came from modern humans (which appeared out of no where 25 million years ago and then disappeared).

This passage is confused on a number of different counts. Firstly, that bird-like theropods are limited to a single locality, the Yixian, is just flat-out wrong. Dromaeosaurids are known from North America (e.g. Bambiraptor, from the Two Medicine Formation of Montana, Dromaeosaurs and Saurornitholestes from the Judith River Formation of Alberta Canada, Deinonychus from the Cloverly Formation of Wyoming), Europe (teeth, mostly undescribed, from the UK and Portugal), Mongolia (Velociraptor from the Djadoctha Formation, Adasaurus from Nemegtskaya Svita), and Africa (undescribed teeth). Oviraptorosaurs are known from North America, Mongolia, Kazakhstan and Uzbekistan. Therizinosaurs have been found in Mongolia and the United States. Alvarezsaurids are known from Mongolia and the US. This is by no means an exhaustive list.

Continue reading  “Guest Column: Casey Luskin and the Evolution of Birds”

Posted by Steve Reuland on June 25, 2004 | Comments (9) | TrackBack (0)

This is the first in an ongoing series about recent discoveries and commentaries concerning aspects of evolution that affect our everyday lives.  On the one hand, it’s a fun way to showcase some of the recent goings-on in the literature, and on the other, it’s a way to rebut the occasional creationist claim that evolution isn’t important to biology or to science at large.  That assertion is false, and would be irrelevant even if true, but in my opinion (and I suspect this is true of most of us here), the aspects of evolution that affect our day-to-day lives are the most fascinating.

Consider the existence of man-made pollutants.  Since the advent of modern chemistry, humans have found ways of making new and useful chemicals that can’t be found in nature.  Unfortunately, part of what makes a chemical useful is its ability to resist breaking-down.  And if it happens that such a chemical gets produced in huge quantities, and that some of this quantity manages to make its way out into our environment, it can be quite a hazard to human and environmental health.  The resistance to degradation becomes a part of the problem, because these chemicals can accumulate over many years to the point where they become toxic.  It’s therefore important for us to understand methods by which these compounds can be eliminated. 

Fortunately, our bacterial friends have evolved ways of dealing with many of the persistent pollutants that have been dumped into the environment.  In a just published review in the Journal of Biological Chemistry, Lawrence Wackett of the University of Minnesota describes some of the enzymes that microbes have evolved to digest these man-made chemicals.  Unlike enzymes that evolved gillions of years ago, many of which have histories that are impossible to reconstruct, these enzymes show signs of having evolved quite recently.  Wackett notes: 

Another lesson being learned from biodegradation studies is that functionally significant enzyme evolution occurs on shorter time scales than previously appreciated; weeks, months and years rather than eons.

Continue reading  “Better Living Through Evolution, pt. 1: Cleaning up a mess/upending the "scientific key" of ID.”

Posted by Steve Reuland on June 23, 2004 | Comments (29) | TrackBack (0)

Scientists Discover Two New Interstellar Molecules: Point to Probable Pathways for Chemical Evolution in Space.

A team of scientists using the National Science Foundation’s Robert C. Byrd Green Bank Telescope (GBT) has discovered two new molecules in an interstellar cloud near the center of the Milky Way Galaxy. This discovery is the GBT’s first detection of new molecules, and is already helping astronomers better understand the complex processes by which large molecules form in space.

The 8-atom molecule propenal and the 10-atom molecule propanal were detected in a large cloud of gas and dust some 26,000 light-years away in an area known as Sagittarius B2. Such clouds, often many light-years across, are the raw material from which new stars are formed.

“Though very rarefied by Earth standards, these interstellar clouds are the sites of complex chemical reactions that occur over hundreds-of-thousands or millions of years,” said Jan M. Hollis of the NASA Goddard Space Flight Center in Greenbelt, Md. “Over time, more and more complex molecules can be formed in these clouds. At present, however, there is no accepted theory addressing how interstellar molecules containing more than 5 atoms are formed.”
[…]

Complex molecules in space are of interest for many reasons, including their possible connection to the formation of biologically significant molecules on the early Earth. Complex molecules might have formed on the early Earth, or they might have first formed in interstellar clouds and been transported to the surface of the Earth.

Molecules with the aldehyde group are particularly interesting since several biologically significant molecules, including a family of sugar molecules, are aldehydes.

“The GBT can be used to fully explore the possibility that a significant amount of prebiotic chemistry may occur in space long before it occurs on a newly formed planet,” said Remijan. “Comets form from interstellar clouds and incessantly bombard a newly formed planet early in its history. Craters on our Moon attest to this. Thus, comets may be the delivery vehicles for organic molecules necessary for life to begin on a new planet.”

I find this pretty interesting, because the enzyme I work with catalyzes an aldehyde dehydrogenase reaction that uses propanal (aka propanaldehyde, aka proprionaldehyde).  We use propanal to assay the enzyme’s activity, so I’ve got a big bottle of propanal sitting in the fridge.  I kind of like the way it smells. 

If you’re wondering what propanal is, think of its little brother, acetaldehyde, which contains two carbon atoms instead of three.  Acetaldehyde is something that most of us have had the joy of communing with, given that it’s the main product of ethanol metabolism.  When you drink, it’s actually the acetaldehyde, and not the alcohol itself, that gets you intoxicated.  A second dehydrogenation turns acetaldehyde into acetic acid, aka vinegar, which gets digested as usual.

Posted by Yang Yang on June 22, 2004 | Comments (210)

With any tavern, one can expect that certain things that get said are out-of-place. But there is one place where almost any saying or scribble can find a home: the bathroom wall. This is where random thoughts and oddments that don’t follow the other entries at the Panda’s Thumb wind up. As with most bathroom walls, expect to sort through a lot of oyster guts before you locate any pearls of wisdom.

The previous wall got a little cluttered, so here is a new one.

Posted by Ian Musgrave on June 22, 2004 | Comments (123) | TrackBack (0)

William Dembski has just posted an essay on human origins on www.designinference.com. If there was any doubt that the Intelligent Design movement was about religious belief rather than science, this essay dispels that doubt.

Continue reading  “Dembski and Human Origins”

Posted by Reed A. Cartwright on June 22, 2004 | Comments (5) | TrackBack (0)

Zoo Atlanta is home to two giant pandas, Lun Lun and Yang Yang.  Lun Lun is an avid climber who enjoys playing throughout the day, while Yang Yang is playful and easygoing.

They are both nearly seven years old and together eat about 220 pounds of bamboo a day.  The zoo relies on bamboo donated from private lands to feed Lun Lun and Yang Yang.  The zoo uses their own team to harvest the bamboo, but I think it would be more interesting if they simply took the pandas out to graze at the site. 

Of notable interest is that the zoo has a webcam of the pandas, available from 10am to 5pm (EST) Tuesday through Friday.  Of course you can guess what they spend most of the day doing.

Only three zoos in the US have pandas: Zoo Atlanta, The San Diego Zoo, and The National Zoo.  Both of these latter zoos also have panda cams: San Diego and The National Zoo.

Posted by John S. Wilkins on June 22, 2004 | Comments (8) | TrackBack (0)

This report has just been issued: Tunes create context like language: Maths shows why tonal music is easy listening.

It set me thinking…

Posted by PZ Myers on June 21, 2004 | Comments (4) | TrackBack (1)

An aquatic sloth?

Skull of Thalassocnus yaucensis, sp. nov., holotype, MUSM 37 in lateral (A), ventral (B), dorsal (C), views; mandible in lateral left (D) and dorsal (E) views.

Carl Zimmer has the details. This is very cool—yet another series of transitional fossils, showing a set of Peruvian sloths, of all things, that adapted to an aquatic lifestyle over the course of several million years.

Posted by Ed Brayton on June 21, 2004 | Comments (6) | TrackBack (2)

I didn’t know that the men’s movement had blogs until I received an e-mail this weekend from Vic (aka David) with a link to one. The subject of the blog entry, much to my surprise, was evolution and the ID movement. Is there some connection between the men’s movement and the ID movement? Many of the same people who are anti-evolution are also strongly anti-feminist, so I suppose there might be, but it still seems a bit out of place. Unfortunately, the author of this blog has no permanent links to specific posts, so you’ll just have to scroll down till you find the title Intellectuals Who Doubt Darwin.

The post was written, according to the text, “by our friend, Hunter Baker the Great”. Long time readers of this blog may remember Hunter Baker as the author of the National Review Online article about the Leiter/VanDyke brouhaha. That situation involved a book review published in the Harvard Law Review by Lawrence VanDyke, a Harvard Law student, of a book about ID and the establishment clause written by Frank Beckwith. Frank is a professor of law at Baylor and a friendly adversary in the evolution/creationism battle who has posted comments here from time to time.

Continue reading  “Hunter Baker Redux”

Posted by PZ Myers on June 20, 2004 | Comments (4) | TrackBack (0)

It's Father's Day, and what does everyone think of on this holiday? What is one thing that we know all fathers have in common, absent dads, neglectful dads, drunk dads, abusive dads, or even caring and responsible dads like the one I had? Why, it's testicles, of course. They all had at least one. So, in honor of the generative apparatus of our paternal predecessors, without which we would not be here, I have put together a few tributes to the testes, commendations to the cojones, a big hand for the balls. There's a little anatomy and physiology, a bit of development, some evolution of the scrotum, and even <shudder> a link to some recipes.