Posted by PvM on August 27, 2004 | Comments (3) | TrackBack (0)

As other PT contributors have already shown, there are many problems with Meyer’s peer reviewed contribution.  I intend to share my research findings here on PT over the coming days as I have researched close to half a dozen claims and references so far.

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Meyer when discussing [1] the Cambrian period states the following

One way to estimate the amount of new CSI [2] that appeared with the Cambrian animals is to count the number of new cell types that emerged with them (Valentine 1995:91—93).

[3]

The full reference reads: Valentine, I. W. 1995. Late Precambrian bilaterians: grades and clades. Pp. 87—107 in W M. Fitch and FJ. Ayala, eds., Tempo and mode in evolution: genetics and paleontology 50 years after Simpson. National Academy Press, Washington, D.C..

The paper also appeared in PNAS as: Valentine, J.W. 1994. Late Precambrian bilaterians: grades and clades. Proc Natl Acad Sci U.S.A. July 19; 91 (15): 6751-6757.

Notice my surprise when I thus read

Continue reading  “Meyer: Cambrian Explosion and CSI?”

Posted by PZ Myers on August 27, 2004 | Comments (22) | TrackBack (0)

The Sarkar Lab at U Texas Austin is maintaining a Hall of Shame, a list of faculty who "must believe that creationism in one of its guises provides a better explanation of biotic change than contemporary evolutionary theory". The list so far is short, and includes the name of the person nominating the faculty member. Bill Dembski is one of the three (the others are RC Koons and J Budziszewski), and the bizarre thing is that he nominated himself.

We can therefore take it on good authority that Dembski is a creationist; I wonder if he'll take exception to the nomination, though?

(via The Loom)

Posted by PZ Myers on August 27, 2004 | Comments (1) | TrackBack (0)

I told you I liked fossils, and here are some more that put yesterday's Junggarsuchus to shame in both age and weirdness. Everyone has heard of the Cambrian 'explosion', but there are also collections of pre-Cambrian fossil animals that have always been rather enigmatic—they just don't seem to correspond well to the morphology of Cambrian, or modern, forms.

Some new specimens from the pre-Cambrian have been described in a paper titled, "Modular construction of early Ediacaran complex life forms." They have been collected from 560 million year old rocks in Newfoundland, Canada. The focus of the paper is on patterns of organization: as the title says, these organisms appear to be modular in form, but it isn't the segmental modularity we see today. Instead, these pre-Cambrian animals were built on a fractal branching plan, repeated iterations of a structure called the "rangeomorph frondlet". The result was a creature that looked feathery or fern-like, and when described, it's hard to avoid using terms we usually associate with plants, like "stalk" and "leaf-like". But don't be confused, these are not plants, nor are they anything like modern animals, such as sea-pens, which have also adopted this kind of morphology.

Continue reading "Ediacaran fossils from Newfoundland" (on Pharyngula

Posted by PvM on August 26, 2004 | Comments (79) | TrackBack (0)

Now that the DVD for ‘Privileged Planet’ has been announced, it is time to remind the readers of why I believe that the Privileged Planet makes for a very poor scientific argument. Although I do believe that the argument serves well as an apologetic and rhetorical tool, which may help explain why it is given such a ‘privileged’ position at the DDD-V conference or creationist websites.

So why do I believe that the Privileged Planet approach is wrong? To quote Xia-Li Meng at the 2004 ENAR Spring Meeting in Pittsburgh PA on statistics:

“If you have not seen all the data, how can you estimate how much you haven’t seen? But, as statisticians, we can do anything!”

Continue reading  “The Privileged Planet: Single data points and naive falsification”

Posted by Reed A. Cartwright on August 26, 2004 | Comments (0) | TrackBack (0)

It has been a while since the last EvoMath.  In this installment I am going to begin to discuss classical selection theory.  Selection occurs when certain alleles are likely to transmit more copies of themselves to the next generation than other alleles at the same locus.  The simplest way to think of this is in terms of the viabilitity of individuals.  If an individual dies before it can reproduce, then it is not able to transmit its genes.  If such a death was influenced by the genes it carried then selection can occur.  Classical selection theory assumes that there exists viability selection and that it is constant, i.e. independent of allele or genotype frequencies.  There is also theory behind frequency-dependent selection, but it beyond the scope of this article.

Read the rest at De Rerum Natura

Posted by Jason Rosenhouse on August 25, 2004 | Comments (0) | TrackBack (0)

After a slightly longer hiatus than I originally intended, EvolutionBlog is now back to regular posting! I update the blog Sundays through Thursdays, usually in the evenings. The idea is that if you stop by Monday-Friday you won't miss naything (perish the thought).

I just completed my analysis of Cornelius Hunter's essay from Uncommon Dissent.

Part one is available here.

Part two is available here.

Part three is available here.

Next up: Tipler!

Posted by Steve Reuland on August 25, 2004 | Comments (62) | TrackBack (0)

‘Super-Earth’ spotted in distant sky

European astronomers announced they had found a “super-Earth” orbiting a star some 50 light years away, a finding that could significantly boost the hunt for worlds beyond our Solar System.

The planet was spotted orbiting a Sun-like star, mu Arae, which is located in a southern constellation called the Altar and which is bright enough to be seen with the naked eye, they said. […]

With few exceptions, the extrasolar planets spotted so far have approximated the size of Jupiter, the giant of the Solar System.

But this latest find is far smaller, with a mass of only 14 times that of the Earth, which puts it in the same ballpark as Uranus for size.

The big difference, though, is that Uranus is an uninhabitable hell, a gassy planet on the far frigid fringes of the Solar System, whereas the new planet appears to be a rocky planet, as the Earth, Mars, Venus and Mercury are, and orbits in a much balmier region.

It has a gassy atmosphere, amounting to about a tenth of its mass, although what this consists of is so far unknown.

The object qualifies “as a ‘super-Earth,” the ESO said.

Much about this enigmatic world remains to be uncovered, least of all whether it may be habitable.

However, there is the tantalising question as to whether it lies within the “Goldilocks Zone” — a distance from its star that is not too hot, not too cold, just right.

In this zone, a planet would be close enough to the star to have liquid water — yet not so close that its oceans would boil away — and not so far that its oceans would freeze. That is one of the prime conditions for creating and sustaining life, according to a leading theoretical model. […]

I suppose if this turns out to be a habitable planet, that would put a serious kink in the “Privileged Planet” arguments.  Though in my opinion those arguments suffer from serious logical flaws and don’t really require emprical disconfirmation, but it’s always cool to know that Super Earth is out there.  Maybe this will finally cause the real estate bubble to burst.

Posted by PZ Myers on August 25, 2004 | Comments (0) | TrackBack (0)

We have the tenth Tangled Bank online…stop on by Wolverine Tom's place and see what's up.

If you'd like to be represented in the 11^th edition in two weeks, send your links to John McKay of Archy. And we're always looking for new people to host the biweekly affair, so if you're interested in that, send a line to pzmyers@pharyngula.org.

Posted by Wesley R. Elsberry on August 24, 2004 | Comments (216) | TrackBack (24)

Review of Meyer, Stephen C. 2004. The origin of biological information and the higher taxonomic categories. Proceedings of the Biological Society of Washington 117(2):213-239.

by Alan Gishlick, Nick Matzke, and Wesley R. Elsberry

[The views and statements expressed here are our own and not necessarily those of NCSE or its supporters.]

“Intelligent design” (ID) advocate Stephen C. Meyer has produced a “review article” that folds the various lines of “intelligent design” antievolutionary argumentation into one lump.  The article is published in the journal Proceedings of the Biological Society of Washington.  We congratulate ID on finally getting an article in a peer-reviewed biology journal, a mere fifteen years after the publication of the 1989 ID textbook Of Pandas and People, a textbook aimed at inserting ID into public schools.  It is gratifying to see the ID movement finally attempt to make their case to the only scientifically relevant group, professional biologists.  This is therefore the beginning (not the end) of the review process for ID.  Perhaps one day the scientific community will be convinced that ID is worthwhile.  Only through this route — convincing the scientific community, a route already taken by plate tectonics, endosymbiosis, and other revolutionary scientific ideas — can ID earn a legitimate place in textbooks. 

Unfortunately, the ID movement will likely ignore the above considerations about how scientific review actually works, and instead trumpet the paper from coast to coast as proving the scientific legitimacy of ID.  Therefore, we would like to do our part in the review process by providing a preliminary evaluation of the claims made in Meyer’s paper.  Given the scientific stakes, we may assume that Meyer, Program Director of the Discovery Institute’s Center for Science and Culture, the major organization promoting ID, has put forward the best case that ID has to offer.  Discouragingly, it appears that ID’s best case is not very good.  We cannot review every problem with Meyer’s article in this initial post, but we would like to highlight some of the most serious mistakes.  These include errors in facts and reasoning. Even more seriously, Meyer’s paper omits discussion or even citation of vast amounts of directly relevant work available in the scientific literature. 

Summary of the paper

Meyer’s paper predictably follows the same pattern that has characterized “intelligent design” since its inception: deny the sufficiency of evolutionary processes to account for life’s history and diversity, then assert that an “intelligent designer” provides a better explanation. Although ID is discussed in the concluding section of the paper, there is no positive account of “intelligent design” presented, just as in all previous work on “intelligent design”.  Just as a detective doesn’t have a case against someone without motive, means, and opportunity, ID doesn’t stand a scientific chance without some kind of model of what happened, how, and why.  Only a reasonably detailed model could provide explanatory hypotheses that can be empirically tested.  “An unknown intelligent designer did something, somewhere, somehow, for no apparent reason” is not a model.

Meyer’s paper, therefore, is almost entirely based on negative argument.  He focuses upon the Cambrian explosion as an event he thinks that evolutionary biology is unable to account for. Meyer asserts that the Cambrian explosion represented an actual sudden origin of higher taxa; that these taxa (such as phyla) are “real” and not an artifact of human retrospective classification; and that morphological disparity coincides with phyletic categories.  Meyer then argues that the origin of these phyla would require dramatic increases in biological “information,” namely new proteins and new genes (and some vaguer forms of “information” at higher levels of biological organization).  He argues that genes/proteins are highly “complex” and “specified,” and that therefore the evolutionary origin of new genes is so improbable as to be effectively impossible.  Meyer briefly considers and rejects several theories proposed within evolutionary biology that deal with macroevolutionary phenomena.  Having rejected these, Meyer argues that ID is a better alternative explanation for the emergence of new taxa in the Cambrian explosion, based solely upon an analogy between “designs” in biology and the designs of human designers observed in everyday experience.

The mistakes and omissions in Meyer’s work are many and varied, and often layered on top of each other.  Not every aspect of Meyer’s work can be addressed in this initial review, so we have chosen several of Meyer’s major claims to assess.  Among these, we will take up the Cambrian explosion and its relation to paleontology and systematics. We will examine Meyer’s negative arguments concerning evolutionary theories and the origin of biological “information” in the form of genes.

An expanded critique of this paper is in preparation.

Continue reading  “Meyer's Hopeless Monster”

Posted by Reed A. Cartwright on August 24, 2004 | Comments (10) | TrackBack (0)

I’m working on a new installment of evomath.  This one is going to be some simple  examples of classical selection theory.  I am probably going to post it on my blog because it is using features of a new version of Kwickcode that I haven’t setup on PT.  I think I am going to wait until PT makes the switch to MT 3.1 before I install version 2 of my plugins here.

Now to encourage me to keep on track with my series, I want readers to make requests.  Is there any particular part of evolutionary theory that you would like me to cover?  Is there something you didn’t quite get from your days as an undergraduate that you want to see again?  Etc.

Posted by Yang Yang on August 24, 2004 | Comments (221) | TrackBack (0)

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 we’ve splashed a coat of paint on it.

Posted by PZ Myers on August 23, 2004 | Comments (8) | TrackBack (0)

The Loom has been quiet for most of the summer, but Carl Zimmer is back with a lucid summary of recent data on human genome evolution—and it may be a little disquieting to those who think monogamy is natural and traditional and the only properly human way to propagate.

Posted by John M. Lynch on August 23, 2004 | Comments (75) | TrackBack (0)

From EurekAlert:

One of the most debated hypotheses in evolutionary biology received new support today, thanks to a study by a scientist at the University of Nevada, Reno. Elissa Cameron, a mammal ecologist in the Department of Natural Resources and Environmental Science, has helped to disprove critics of a scientific theory developed in 1973.

At that time, ecologist Bob Trivers and mathematician Dan Willard said that large healthy mammals produce more male offspring when living in good conditions, such as areas where there is an ample food supply. Conversely, female mammals living in less desirable conditions would tend to have female offspring.  …

She conducted an analysis of 1,000 studies that examined the Trivers-Willard hypothesis and sex ratios in mammals. Her study found that female mammals that were in better body condition during the early stages of conception were more likely have male offspring. Body fat and diet can affect levels of glucose circulating in a mammal’s body, and Cameron suggests that the levels of glucose around the time of conception could be influencing the sex of the animal’s offspring.

“A high-fat diet can result in higher levels of glucose, thereby supporting the hypothesis that glucose may be contributing to the sex of the mammal’s offspring,” Cameron said.

The paper is Elissa Z. Cameron, “Facultative adjustment of mammalian sex ratios in support of the Trivers-Willard hypothesis: evidence for a mechanism” Proceedings of the Royal Society of London, Ser. B.  271, 1723 - 1728 ( DOI: 10.1098/rspb.2004.2773). 

Abstract:

Evolutionary theory predicts that mothers of different condition should adjust the birth sex ratio of their offspring in relation to future reproductive benefits. Published studies addressing variation in mammalian sex ratios have produced surprisingly contradictory results. Explaining the source of such variation has been a challenge for sex-ratio theory, not least because no mechanism for sex-ratio adjustment is known. I conducted a meta-analysis of previous mammalian sex-ratio studies to determine if there are any overall patterns in sex-ratio variation. The contradictory nature of previous results was confirmed. However, studies that investigated indices of condition around conception show almost unanimous support for the prediction that mothers in good condition bias their litters towards sons. Recent research on the role of glucose in reproductive functioning have shown that excess glucose favours the development of male blastocysts, providing a potential mechanism for sex-ratio variation in relation to maternal condition around conception. Furthermore, many of the conflicting results from studies on sex-ratio adjustment would be explained if glucose levels in utero during early cell division contributed to the determination of offspring sex ratios.

Posted by PZ Myers on August 23, 2004 | Comments (2) | TrackBack (0)

I spent part of my weekend reading a very nice, detailed paper by Soderlund and Knipple (thanks for the recommendation, Nick!) on the distribution and mechanisms of mutations that confer pesticide resistance on insects. The main message is that we have been using potent pyrethroid poisons that have a common mechanism, targeting the highly conserved sodium channel of the nervous system, and that similar mutations that reduce the affinity of the channel for the pyrethroid are popping up in many insect species.

Continue reading "Better bug killing through Science" (on Pharyngula)

Posted by PZ Myers on August 23, 2004 | Comments (0) | TrackBack (0)

It's Tangled Bank time again. I've sent a link to some science blogging to Tom of Wolverine Tom…have you?

Posted by PvM on August 22, 2004 | Comments (9) | TrackBack (0)

Gary Hurd takes on the claims by Dembski that the ‘explanatory filter’ is how in archaeology or criminology ‘intelligent design’ is detected to show that these claims are incorrect.

Anyone familiar with the lastest crime shows on TV, especially about crime scene investigations, knows that criminology works with concepts like means, motives and opportunity. None of these factors plays any role in an ‘explanatory filter’. Hurd makes a compelling case that the methods used by archaeologist and criminologists does not mimick the ‘explanatory filter’ . In fact, he shows why the ‘explanatory filter’ would be largely useless.

It is understandable that ID wants to avoid dealing with means or motives at all cost, hence the (erroneous) suggestion that design can be reliably inferred without any knowledge or assumptions about the designer.

Continue reading  “Why Intelligent Design Fails: Chapter 8 "The explanatory filter, archaeology, and Forensics" Gary Hurd”