The Annotated Origin of Species

In November of 1859, the
London publishing house of John Murray brought out the first edition of what would become the most famous and important work of science of the 19th century: Charles Darwin's On the Origin of Species. The first edition of 1,250 copies sold out in one afternoon (first edition copies today fetch over a hundred thousand dollars on the rare book market) and was eventually reprinted over the next fifteen years in five increasingly popular editions. The success of the Origin catapulted Darwin from a relatively unknown specialist in the taxonomy of barnacles to the most famous naturalist of the 19th century and became the most widely read (and most controversial) science text of all time.

Many historians of biology credit the Origin with founding the modern science of biology. Hence, it is very curious that the first edition of the Origin lacks what most scholars expect to find in such influential and widely respected works. Unlike most other books of its kind — including Darwin's other famous books, The Voyage of the Beagle (first published in 1839) and The Descent of Man (first published in 1871) — the Origin has virtually none of the usual "machinery" of a scholarly work. Although Darwin cites the findings and opinions of hundreds of naturalists worldwide in the Origin, he does not provide any footnotes or written citations to their published works. The first edition of the Origin also does not include a bibliography nor any listing of published references. And, despite focusing on the most visual of the natural sciences, the Origin contains only one illustration, a hand–drawn diagram of the branching pattern of descent that Darwin proposed for his theory of descent with modification (his term for what we now refer to as "evolution").

The reason for this surprising lack of documentation is well known: Darwin had been scooped on his theory of natural selection by a fellow English naturalist, Alfred Russel Wallace. In April of 1858, Wallace sent Darwin a letter that included a brief essay "On the Tendency for Varieties to Depart Indefinitely from the Original Type", in which Wallace anticipated virtually all of the major concepts of Darwin's theory of evolution by natural selection. Darwin had been working on his theory for over two decades, and had been writing the book that would eventually be published as the Origin for at least five years when he received Wallace's letter. Anxious to preserve his priority as the discoverer of natural selection and urged on to do so by his friends and fellow naturalists, Darwin rushed what he considered to be an "abstract" of his ideas into print in November of 1859. This "brief abstract", published without footnotes, illustrations, or bibliography, was the first edition of the Origin of Species by Means of Natural Selection.

The first edition of the Origin was a masterwork and is still published in its original form, without footnotes, illustrations, and bibliography. Reading it, one can still get a taste of the overwhelming scholarship with which Darwin supported what he called his "long argument" for descent with modification. However, to really appreciate how much of the science of natural history Darwin wove into his argument, one really needs to know what Darwin's sources were and how they were related to each other.

Presenting these sources and showing how Darwin marshaled them in his defense of his theory is the heart of James Costa's brilliant annotation of Darwin's classic, The Annotated Origin, published by Belknap Press of Harvard University Press. Brought out in celebration of the 150th anniversary of the publication of first edition of the Origin, Costa's annotated version more than compensates for the "missing" material in Darwin's original. The introduction to The Annotated Origin alone is worth the price of the book. In it, Costa presents a lightning biography of Darwin and a nuanced exploration of the reasons for his rush to publish in 1859. It also contains a reader's guide to the Origin, a book that is often difficult for modern readers who are unaccustomed to the density of Victorian prose. Costa then analyzes and annotates virtually every page of the Origin, including the title page, in which he provides a brief history of Darwin's illustrious publisher, John Murray, and his decision to print only 1,250 copies of what would eventually become his best-selling and most famous publication.

Costa's annotations run the gamut from personal anecdotes to hard-science references. He weaves together Darwin's own telegraphic notes in his unpublished notebooks, his correspondence, his other published works, and his autobiography, providing the reader with a wealth of information and insight. Tracking down each line of evidence becomes a kind of "exploration" in itself. One can follow threads of evidence that elucidate Darwin's views about nature, science, his fellow naturalists, and even such "taboo" subjects (at least in the Victorian era) as sex and the intimate details of family life.

Costa's annotations also provide a detailed framework for Darwin's argument, showing how the various explanations and examples are marshaled in such a way as to support Darwin's underlying argument for "descent with modification by means of natural selection." As just one example, consider Costa's annotations to the section of pigeon breeding in the first chapter of the Origin ("Variation Under Domestication"). Naïve readers of this chapter are sometimes puzzled by Darwin's emphasis on pigeon breeding and its relationship to his theory. But, as Costa points out, "[p]igeons provided a microcosm of Darwin's model of selection, as well as valuable data on development, correlation of traits, and reversion." Like so many of his Victorian contemporaries, Darwin raised pigeons at his country estate at Down House in Kent, and conducted dozens of breeding experiments to test his theories. Darwin pointed out that all of the various breeds of pigeons could be shown to have descended from the wild rock pigeon (Columba livia) by a process that we now refer to as artificial selection. Darwin constructed an argument by analogy that natural selection followed the same rules as artificial selection. And, since so many of his contemporaries (and potential readers) were also pigeon fanciers, he could be reasonably confident that they would be able to follow his argument without extensive explanation or citations of obscure references to the scientific literature.

Reading the first edition of Darwin's Origin of Species is a revelation. One catches the threads of Darwin's argument and follows his reasoning through to his startling (and sometimes troubling) conclusions. James Costa's masterful annotation of the Origin does much more. It supplies the scholarly apparatus that the first edition lacked and provides a coherent and comprehensive background for Darwin's arguments, as well as many fascinating insights into Darwin's personality, thought processes and research methods. No other scientist has been as exhaustively analyzed as Darwin, and no other published work of science has been as widely criticized or praised as the Origin of Species. Reading James Costa's Annotated Origin provides an even deeper appreciation for Darwin's achievement and its impact on science and society.

************************************************

As always, comments, criticisms, and suggestions are warmly welcomed!

--Allen

Read More

November 24, 2009

150th Birthday of The Origin of Species!

This has been the year of Charles Darwin, British naturalist and author of The Origin, because this year marks his bicentennial birthday as well as the sesquicentennial anniversary of the publication of his most famous book.

On this date in 1859, the first printing of The Origin of Species went on sale. Priced at 15 shillings each, the 1,250 copies immediately sold out, and 3,000 more copies were quickly ordered. According to the Word Wench's blog, “Swordplay,” “British conservatives were shocked: this heretical pop science book was being read in the drawing room, in the high street!”

Darwin's theory of evolution through natural selection is a primary foundation of biology. According to Wikipedia, “Darwin's book introduced the theory that populations evolve over the course of generations through a process of natural selection. It presented a body of evidence that the diversity of life arose through a branching pattern of evolution and common descent.” Natural selection, which offers the explanatory power of Darwin's theory, states that, of those traits that can be inherited, the traits that make it more likely that a creature will live longer and reproduce more successfully tend to become more common in populations over subsequent generations.

In simpler terms, lifeforms change over time. Traits of creatures that succeed in having lots of babies are, of course, the traits that are passed down to those babies.

Darwin's book was meant for the general public as well as for other scientists. Darwin was a very good writer and tried hard to be understood. The end of The Origin has been quoted often this year, for good reason:

There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.

• The Tree of Life web project aims to “contain a page with pictures, text, and other information for every species and for each group of organisms, living or extinct.” It is being compiled from experts and amateurs. Browse around—there are dinosaurs and jellyfish and all manner of other creatures here!

A simpler website with a browse-able “tree of life” can be found here.

• .There are lots of other sorts of activities here.

Read More

"Can Natural Selection Produce New Information?"

Here's another in a series of responses to some common assertions/misunderstandings of evolutionary biology by creationists and "intelligent design" supporters. One of the most common arguments against the theory of evolution is that natural selection cannot produce genuinely new information:

"Natural selection does not produce new information. On the contrary, it only reduces existing genetic information. Evolutionary biologists shouldn't invoke mutations as a source of new information, because all known mutations involve a net loss of information."

This viewpoint demonstrates a basic misunderstanding of the process of evolution bynatural selection. According to Darwin (and virtually all evolutionary biologists), natural selection has three prerequisites:

1) Variety, generated by the "engines of variation";

2) Heredity, mediated by the transfer of genetic material (either vertically - from parents to offspring - or horizontally - via viral transduction, retrotranscription, etc.); and

3) Fecundity, that is, reproduction, usually at a rate that exceeds replacement (according to Malthus).

Given these three prerequisites, the following outcome is virtually inevitable:

4) Demography: Some individuals survive and reproduce more often than others. Ergo, the heritable variations of such individuals become more common over time in populations of those organisms.

Natural selection is synonymous with #4; it is an outcome of the three processes listed as prerequisites, not a "mechanism" in and of itself.

Ergo, the real dispute between evolutionary biologists and "intelligent design" supporters is not over natural selection per se, but rather the properties and capabilities of the "engines of variation". I have written extensively about these here and here.

Yes, natural selection (i.e. #4, above) is conservative not creative. It produces no new genetic nor phenotypic information, which is why Darwin eventually came to prefer the term "natural preservation" rather than "natural selection". However, it is also clear that the "engines of variation" - that is, the processes the produce phenotypic variation among the members of populations of living organisms - are both extraordinarily creative and extraordinarily fecund. The real problem in biology is therefore not producing new variation, but rather limiting the production of new variation to the point that the "engines of variation" do not cause the inevitable disintegration of living systems.

As just one example of this problem, the genetic elements known as transposons generate a huge amount of new genetic variation, much of which is either phenotypically neutral or deleterious to the organism. There are biochemical mechanisms by which cells can monitor the incidence of transposition in themselves, and limit its consequences (up to and including the active self-destruction of the cell via apoptosis).

At the same time, there is very good evidence in the genomes of many organisms that retrotransposition events mediated by transposons have occasionally produced genetic changes that have resulted in increased survival and reproduction of the organisms in which such events have taken place. There is a large and growing literature on this phenomenon, all of which points to the inference that retrotransposition via transposons both creates new genetic and phenotypic variation, and that in some cases such variation can provide the raw material for evolutionary adaptations, which are preserved via natural selection.

So, if someone really wants to find out where the Intelligent Designer might create new variations, they should follow the lead of Darwin's good friend, Asa Gray, and look for the telltale evidence (if any) for such intervention in the "engines of variation". Of course, they would have to show pretty conclusively (using empirical investigations and statistical analysis) that such "creation events" are not the result of purely natural, unguided processes. If they can do this, they will undoubtedly win a Nobel Prize and a Crafoord Prize (plus a MacArthur or two).

Notice that this will involve looking carefully into the mechanisms by which new variations are produced, rather than pointing to the outcomes of such processes (i.e. natural selection) and simply asserting that "you can't get here from there". Simply asserting (without empirical evidence) that something can't happen isn't "doing science" at all. In fact, it's doing just the opposite...

...it's doing ID the way it's always been done up until now; by press release, rather than by empirical research.

As always, comments, criticisms, and suggestions are warmly welcomed!

--Allen

Read More

"Why Do We Have The Senses That We Have?"

A common debating tactic used by creationists and ID supporters is to ask, "why do we have the senses that we have, and not some other ones"? The answer they usually provide is something like, "because that's the way the Intelligent Designer intended them to be".

The question of why we have the senses that we do is a very interesting one. As just one example, consider the sense of sight. As a type G2V yellow dwarf star, the sun gives off a relatively narrow range of electromagnetic radiation, including (from longest wavelength to shortest) radio waves, infrared radiation, “visible (red, orange, yellow, green, blue, and purple) light", and ultraviolet light. Almost all of these wavelengths of electromagnetic radiation can penetrate the Earth’s atmosphere (although the shorter wavelengths of ultraviolet light are somewhat attenuated by absorption by ozone/O3 in the upper atmosphere).

So, which wavelengths of electromagnetic radiation can we perceive? The answer depends on who you define as “we". Vertebrates have visual pigments in the cone cells of the retina that can absorb only three of these wavelengths: red (absorbed by the rhodopsin protein erythrolabe, which absorbs sunlight in the range of 564–580 nanometers), green (absorbed by the rhodopsin protein chlorolabe, which absorbs sunlight in the range of 534–545 nanometers), and blue (absorbed by the rhodopsin protein cyanolabe, which absorbs sunlight in the range of 420–440 nanometers). So, we vertebrates can only directly perceive red, green, and blue light (that’s why color computer monitors generate only red, green, and blue pixels).

However, most insects (including honey bees) have different visual pigments, and so see very different colors than we do. They do not have a visual pigment that corresponds to vertebrate erythrolabe, and so cannot perceive the color we call “red". However, they have a visual pigment vertebrates do not have, which can absorb light in the near ultraviolet range. Hence, insects can see colors (including ultraviolet) that we cannot see, and so the world appears very different to them.

So far, no organism on Earth has been discovered that can perceive the radio waves given off by the sun. This is probably because to do so would require absorptive structures several meters in length (the wavelength of most radio waves).

So, one answer to the creationist's question is that, taken as a whole, living organisms can perceive (or at least absorb) a range of light from the far infrared to the near ultraviolet, but lack receptors for most of the electromagnetic spectrum (such as radio waves, gamma radiation, etc). In other words, the range of electromagnetic radiation that can be perceived by living organisms matches quite closely the range of electromagnetic radiation given off by the sun and transmitted through the Earth’s atmosphere (with the exception of radio waves, which are too long to by absorbed by any known biological molecule).

That this is the case is exactly what one would expect to have evolved by natural selection, which can only work with what is available. Furthermore, it illustrates one of the basic ideas of evolutionary descent with modification: that the solutions to evolutionary problems vary from group to group as the result of historical contingency. Vertebrates see red, green, and blue, while insects see green, blue, and ultraviolet because two of our visual pigments (chlorolabe and cyanolabe) evolved before the divergence of insects and vertebrates from our common ancestor, while the third visual pigment evolved independently in the two groups, resulting in two different sets of perceived colors.

Compare this to the answer that ID provides: vision is the way it is because that’s how the Intelligent Designer intended it to be. Which of these answers to the creationist's query involves detailed empirical scientific investigation, and which simply relies on unsupported assertions?

As always, comments, criticisms, and suggestions are warmly welcomed!

--Allen

Read More

It's Darwin-Malthus Day!

AUTHOR: Allen MacNeill

SOURCE: Original essay

COMMENTARY: That's up to you...

Most readers of this blog are aware that next year is the Darwin Bicentennial. It's the 200th anniversary of the birth of Charles Darwin and the 150th anniversary of the publication of the Origin of Species. Regular readers also know that this celebration really started this past July 1st, which marked the 150th anniversary of the joint presentation of Darwin and Wallace's theory of evolution by natural selection at the summer meeting of the Linnean Society in London.

However, what many people don't know is that today is also a very significant anniversary of a crucial development in Darwin's theory of evolution by natural selection. On this day in 1838, Darwin

"...happened to read for amusement 'Malthus on Population,' and being well prepared to appreciate the struggle for existence which everywhere goes on from long-continued observation of the habits of animals and plants, it at once struck [him] that under these circumstances favourable variations would tend to be preserved, and unfavourable ones to be destroyed. The result of this would be the formation of new species." [Darwin's Autobiography, page 83]

According to his autobiography, Darwin read Malthus' famous essay in the evening, and the idea of natural selection sprang fully formed into his mind: "Here then I had at last got a theory by which to work...", and indeed he had. But Darwin was an extraordinarily cautious man, always seeking to avoid controversy and notoriety. In his autobiography he says,

"...I was so anxious to avoid prejudice, that I determined not for some time to write even the briefest sketch of it."

And indeed, he did not. It wasn't until 1842 that he felt confident enough about his theory to set it down on paper, and it wasn't until two years later that he had this original "pencil sketch of 1842" copied out and put into a form that he felt confidant enough about to share with his closest friends. It was this "Essay of 1844", along with a letter to the American botanist, Asa Gray, that were read at the July, 1858 meeting of the Linnean Society along with Alfred Russell Wallace's unpublished manuscript "On the Tendency of Varieties to Depart Indefinitely from the Original Type", which marks the beginning of evolutionary theory's annus mirabilis.

So, the "evolution revolution" really began on a rainy evening in late September in 1838, when Charles Darwin read Malthus "for amusement"...

...and it's also my birthday.

As always, comments, criticisms, and suggestions are warmly welcomed!

--Allen

Read More

Announcing a New Blog: Evolutionary Psychology

AUTHOR: Allen MacNeill

SOURCE: Evolutionary Psychology

COMMENTARY: That's up to you...

As if I didn't already have enough to do, I have started a new blog. Entitled "Evolutionary Psychology", it is intended as a companion blog to The Evolution List. I have felt for quite a while that there are no really informative blogs on the subject of the evolution of human behavior, and so decided this morning to do one myself.

I have been learning about and doing research in evolutionary psychology for over thirty years (that is, since it used to be called "sociobiology"). Several years ago, I prepared a series of lectures on the subject, complete with images, links, and references, which I intended to use as the basis for a course on the subject. These "lectures" will therefore serve as the core of the new Evolutionary Psychology blog.

The first post on the new blog (The Capacity for Religious Experience is an Evolutionary Adaptation for Warfare) is a repost of one of the most popular posts here at The Evolution List. I have reposted it again, partly to commemorate the 63rd anniversary of the atomic bombing of Hiroshima, and partly to give the new blog a good kickoff. I hope you will take a look, and if you like it, please spread the news.

As always, comments, criticisms, and suggestions are warmly welcomed!

--Allen

Read More

Are Adaptations "Real?"

AUTHOR: Allen MacNeill

SOURCE: Original essay

COMMENTARY: That's up to you...

In an ongoing thread at Design Paradigm, Salvador Cordova wrote:

“There are many designed features in biology that make no sense in terms of natural selection but make complete sense in terms of design.”

This statement demonstrates a profound misunderstanding of both the concept of “design” and of “natural selection,” a misunderstanding which lies at the heart of the evolution/design debate. What is “design” anyway? Note that I’m not asking the question that Dr. Dembski thought he was answering, i.e. how can we tell if something has been designed. Before one can even ask that question (much less attempt to answer it), one must first agree on what “design” is.

This is not a trivial problem. Michael Ruse, in Darwin and Design: Does Evolution Have a Purpose?, asserts that one of the most important contributions of Darwin’s theory was that it put “design” back into nature (from which it had been removed by the “Newtonians”). To Ruse, “design” is essentially equivalent to “adaptation,” in that adaptations “solve” problems of biological function.

But the problem here is one that Lewontin and Gould addressed almost 30 years ago in their landmark paper “The Spandrels of San Marco...”. Lewontin and Gould pointed out two things: (1) not all of the characteristics of living organisms are adaptations (i.e. some of them are the result of pure “chance,” not necessity), and (2) even the characteristics that are clearly adaptive don’t have to have arisen because they are adaptive, nor will they continue to exist for the same reason. They coined the term “exaptation” to refer to characteristics of organisms that are not necessarily adaptive, but which nonetheless are biologically significant.

I would go much further than Lewontin and Gould: just as Darwin suggested (but did not come right out and say) that there are no such things as “species” (see "Origin of the Specious" in this blog), I believe that in nature there are no such things as “adaptations,” at least not insofar as such "adaptations" are "solutions" to biological "problems." That is, although there are characteristics of organisms that are correlated with relatively high reproductive success (and would therefore be considered by most evolutionary biologists to qualify as “adaptations”), it becomes problematic to decide exactly which of those characteristics are the “real” adaptations and which are merely “accidental.” Indeed, if one is serious about the variation/inheritance/fecundity/differential reproductive success model of evolution (i.e. the genuine article, not the RM+NS straw-man attacked by most IDers), then all of the characteristics of living organisms are “accidental” insofar as their origin cannot be shown to have been “intended” or “pre-destined” ahead of time.

Here is the real crux of the disagreement, as PvM has pointed out: what qualifies as an “adaptation” in biology can only be determined retrospectively, insofar as it has the practical result of causing increased relative survival and reproduction. No characteristics of living organisms can be shown to have come into being because they would eventually have that result; indeed, I would assert that to even make this claim is non-sensical in the extreme. What characteristics of living organisms currently alive will eventually result in their assendance or demise? We have absolutely no way of knowing, nor even of imagining a way of knowing. At some point in the future, we can look back and say “son-of-a-gun, those funny looking scales are correlated with increased survival and reproduction because they allow the animals that have them to fly, and therefore escape predators and capture prey more effectively,” but until this actually happens (and absolutely nothing in nature guarantees that it will), we can’t make any statements about the “value” of any of the characteristics of organisms now living.

This, rather than the rather vapid speculations Salvador cited for the future of genetic engineering, is the real value of genetic engineering to evolutionary biology (and vise versa). We now have the ability to selectively delete individual characteristics from many different organisms. This makes possible something that natural selection does not: the precise determination of the selective “value” of particular characteristics. This has already been done, and the surprising outcome has been that even some gene sequences that were thought to have been very important in selection (due to having been “conserved” over deep evolutionary time) are apparently insiginificant or even useless. We know this because knocking them out of the genome has no discernible effect on the survival or reproduction of the “knock-out” progeny. If one is the kind of “pan-adaptationist” that Lewontin and Gould criticized, this outcome should come as a severe shock, as it should to every IDer. But, if one is a true “Darwinian” (i.e. a devotee to that tradition which questions absolutely all assumptions, including the very existence of “adaptations” and “species”), it should come as no surprise at all.

--Allen

REFERENCES CITED:

Gould, S. J. and Lewontin, R. C. (1974) "The Spandrels of San Marco and the Panglossian Paradigm: A Critique Of The Adaptationist Programme" Proceedings Of The Royal Society of London, Series B, Vol. 205, No. 1161, pp. 581-598.

Read More

Random Mutation and Natural Selection Revisited

AUTHOR: Allen MacNeill

SOURCE: Original essay

COMMENTARY: That's up to you...

Promoters of "intelligent design theory" and other forms of creationism often assert that random mutation plus natural selection (RM+NS) are insufficient to explain the diversity of life on Earth. In particular, people like William Dembski assert that RM+NS cannot work fast enough (even given billions of years) to produce the complex living organisms we observe around us.

In so doing, they attack evolutionary theory using a "straw-man argument," because modern evolutionary theory is not limited to RM+NS alone to produce adaptations, nor to explain the diversity of life on Earth. In particular, while there is no empirical evidence that would lead one to believe that mutations are produced by an "intelligent designer," it is also not true that mutations alone must supply the variation necessary for evolution by natural selection.

In particular, while it is true that any given mutation is random (as far as we can tell), a series of mutations which are then preserved as the result of natural selection aren't really random at all, at least not in the way that is often depicted by critics of evolutionary theory. In classical evolutionary theory, as first mathematically formalized by R. A. Fisher, the variation that is necessary for the raw material for natural selection is the result of a large number of individual alleles, all producing variations of the same trait, such as height or skin color in humans. In this model, a normal distribution of heights or skin colors are produced by combinations of different alleles, each influencing some fraction of the overall height, producing what Fisher and others called "continuous variation." Selection then preserved one or a few of the various allele combinations by preserving the individuals that carried the controlling alleles.



In this model, evolutionary change would necessarily be slow and gradual, as changes in the overall mean value for any trait would require the gradual accumulation of mutations in each of the many alleles that controlled the trait. Since the observable mutation rate is very low (at least, the rate of mutations that significantly affect most phenotypic traits is very low), the argument was that directional change in any given trait was something like a wagon train: only as fast as its slowest constituent. That is, change in the overall distribution of the trait (such as height) depended on the rate of mutation of all of the alleles controlling it, and required that a sufficient proportion of the alleles that were preserved by selection mutate and then be selected in the same "direction" (e.g. for greater height).

However, subsequent field and laboratory investigations into the genetic and developmental control of such variable traits have shown the multiple allele/continuous variation model upon which the "modern synthesis" was based is, in fact, not the way most traits apparently evolve. For example, consider a mutation that causes an increase in size of a particular anatomical feature (e.g. a finch's beak). Most such features are regulated by a set of genes that are themselves regulated by a homeotic gene (or a few such homeotic genes; in the case of Darwin's finches, the controlling homeotic gene is called bmp4, for "bone morphology protein 4") [1]. Homeotic genes, like many but not all genes, do not produce a purely monotonic trait (i.e a trait with no variation). Instead, they produce a trait that varies somewhat between individuals, in what approximates a normal distribution. In the case of finch beaks, this means that in any population of finches, there are some individuals with small beaks, some with large beaks, and most with intermediate beaks. All of these finches could easily have the same allele for the homeotic gene controlling the trait. The variation in beak size would therefore be the result, not of the expression of different alleles, but rather of the different outcomes of the expression of the same allele of the homeotic gene, developing differently in different individuals as the result of a combination of chance and environmental conditions (this is how humans differ in heights, for example).



Now consider a situation in which an environmental change (for example, a drought), selected for individual finches with larger beaks. At the level of the controlling homeotic gene, this could mean one of two things: either the larger beaks are still within the developmental limits of the original allele, or another allele (i.e a mutant) has arisen, with an overlapping developmental pattern but a higher mean value for beak size. If the former is the case, then a return to the original environment would result in a return to the original mean beak size.

However, if the latter were the case, then there would be a built-in bias toward finches with larger beaks in the resulting population. This would also mean that the "base" allele - i.e. the new mutant allele - would start out producing a larger mean beak size along with the usual normal distribution of beak sizes. If the environmental change persisted, new alleles might arise, but they would begin with a "norm of reaction" that would produce significantly larger mean beak sizes, along with a normal distribution with significantly larger beaks at the upper tail of the distribution.

In other words, the existing alleles for such a trait would bias subsequent mutations in the "direction" of larger beaks, simply because the pool of potential new alleles would already start out biased in that direction. Therefore, the mutations and developmental changes that were available from one generation to the next would be biased in the direction of whatever phenotypic trait resulted in the highest reproductive success.

This process, called genetic accommodation [2], is part of the new science of evo-devo, which renders much of the classical "evolutionary synthesis" obsolete, and at the same time explains how such phenomena as punctuated equilibria can be integrated into a unified theory of evolutionary development. In particular, genetic accommodation and similar processes can explain how natural selection alone can produce both rapid and directional change in phenotypes over time, thereby making any resort to "intelligent design" unnecessary and irrelevant.

REFERENCES CITED:

[1] Pennisi, E. (2004) Bonemaking protein shapes beaks of Darwin's finches. Science, Vol. 305. no. 5689, p. 1383, available at : http://www.sciencemag.org/cgi/content/summary/305/5689/1383

[2] West-Eberhard, M. J. (2003) Developmental Plasticity and Evolution. Oxford, UK, Oxford University Press. See especially pages 147 to 158.

--Allen

Read More

The Capacity for Religious Experience Is An Evolutionary Adaptation to Warfare

AUTHOR: Allen MacNeill

SOURCE: Original essay

COMMENTARY: That's up to you...

Given the sudden increase in readership of this list, I'm going to take the shamelessly opportunistic route and post a summary of my most recent publication: "The capacity for religious experience is an evolutionary adaptation to warfare", in Fitzduff, M. & Stout, C. (eds) (2005) The Psychology of Resolving Global Conflicts: From War to Peace, vol. 1, ch. 10, pp. 257-284. This, like the recent upsurge in interest in polygamy, is a very hot topic. Terrorism is very much in the news, and since a lot of it seems to be at least peripherally associated with extreme religious views, the idea that these can be part of an evolutionary "arms race" seems very timely.

I first gave a version of this paper at the 2004 annual conference of the New England Institute in Portland, Maine. It has since been published among the proceedings of that conference (the citation is: MacNeill, A. (2004) "The capacity for religious experience is an evolutionary adaptation to warfare" Evolution & Cognition, vol. 10, no. 1, pp. 43-60). I was later contacted by Mari Fitzduff and Chris Stout for inclusion in their anthology on peace and war, which was published last December. The latter is a terrific collection, but a little pricey (I'm glad I got a free copy out of the deal). If readers are interested, I can email a pdf of the entire paper. It's pretty good, if I do say so myself.

But why should you take just my word for it? Here's the abstract and the "core of the argument":

ABSTRACT

The criteria for deciding whether a characteristic qualifies as an evolutionary adaptation are discussed: differential survival and reproduction are considered the most appropriate criteria. The pan-specific qualities of both religious experience and warfare indicate that they are both evolutionary adaptations. There is considerable variation between individuals with respect to their capacity for religious experience and motivation to participate in warfare. Selective advantages for participation in warfare accrue to both winners and losers as long as the benefits of participation exceed the average costs. These selective advantages, primarily in the form of differential reproductive success, accrue to males when they are on the winning side in a war, and often to females no matter which side they are on.

Recent work on the evolutionary dynamics of religion have converged on a "standard model" in which religions and the supernatural entities which populate them are treated as epiphenomena of human cognitive processes dealing with the detection of and reaction to agents under conditions of stress, anxiety, and perceived threat. Religious experience at the individual level is characterized by depersonalization, coupled with submission to a super-individual force; the same is essentially the case for participation in warfare. The capacities for both religious experience and participation in warfare are adaptations insofar as they evolve by means of natural selection operating primarily at the level of individuals who are members of groups in which both kin selection and reciprocal altruism are also operative. It is likely that the overall patterns of supernatural organization exist as the result of coevolution between the memetic content of religious beliefs and the underlying neurological matrix within which such beliefs are maintained and transmitted in the context of specific ecological subsistence patterns.

THE CORE OF THE ARGUMENT

War involves violent force, up to and including killing people. To participate in a war means to participate in an activity in which there is a significant probability that one will either kill other people, or will be killed by them.

This means that any participant in warfare is faced with the possibility of painful and violent death as the result of such participation. Given this probability, if natural selection acts at the level of individuals, how can natural selection result in a propensity to participate in warfare? Clearly, either the probability that one will be killed must be perceived as low or the potential payoff from such participation must be perceived as high. If natural selection is to operate at the level of individuals, these two circumstances should ideally be obtained simultaneously,

Here is where the capacity for religious experience is crucial. By making possible the belief that a supernatural entity knows the outcome of all actions and can influence such outcomes, that one's "self" (i.e., "soul") is not tied to one's physical body, and that if one is killed in battle, one's essential self (i.e., soul) will go to a better "place" (e.g., heaven, valhalla, etc.) the capacity for religious experience can tip the balance toward participation in warfare. By doing so, the capacity for religious belief not only makes it possible for individuals to do what they might not otherwise be motivated to do, it also tends to tip the balance toward victory on the part of the religiously devout participant. This is because success in battle, and success in war, hinges on commitment: the more committed a military force is in battle, the more likely it is to win, all other things being equal. When two groups of approximately equal strength meet in battle, it is the group in which the individuals are more committed to victory (and less inhibited by the fear of injury or death) that is more likely to prevail. To give just one example, the battle cry and motto of the clan Neil has always been "Buaidh na bas!" - "Victory or death!"

Religions tell people what they most want to hear: that those agents and processes that they most fear have no ultimate power over them or pose no threat to themselves or the people they care about. In particular, by providing an intensely memorable, emotionally satisfying, and tension-releasing solution to the problem of mortality, religions make it possible for warriors to master their anxieties and do battle without emotional inhibitions. This makes them much more effective warriors, especially in the hand-to-hand combat that humans have fought throughout nearly all of our evolutionary history.

Consider the characteristics that are most often cited as central to religious experience. Newberg and d'Aquili (2001) have presented an integrated model of the neurobiological underpinnings of religious experience. They have pointed out that central to most religious experience is a sensation of awe, combined with "…mildly pleasant sensations to feelings of ecstasy." (Newberg and d'Aquili, 2001, p. 89) They have shown that such sensations can be induced by rhythmic chanting and body movements, combined with loud music and colorful visual displays, all of which produce a condition of sensory overload. This process then induces a neurological condition characterized by a sense of depersonalization and ecstatic union with one's surroundings.

This is precisely what happens as the result of military drill and training. It is no accident that humans preparing for war use exactly the same kinds of sensory stimuli described by Newberg and d'Aquili. They have tied such displays to religious activities, and shown the deep similarities between religious rituals and secular ones: "…patriotic rituals… emphasize the "sacredness" of a nation, or a cause, or even a flag…turn[ing] a meaningful idea into a visceral experience." (Newberg and d'Aquili, p. 90) The two types of activities - religious rituals and patriotic rituals - use the same underlying neurological pathways and chemistry.

Religious experience is often equated with a state of mystical union with the supernatural. But what exactly does this mean, and in the context of this presentation, is there a connection between mystical experience and warfare? The answer is almost certainly yes. That combatants have had experiences that would be classified as mystical before, during, and after battle is a simple historical fact. The Scottish flag is based on just such an experience: the white crossed diagonal bars against a field of azure of the St. Andrew's cross is said to have appeared to King Hungus and his warriors during a battle against in the Saxons. Legend says this so encouraged the Scots and frightened their adversaries that a victory was won.

A common thread in all mystical experiences is a loss of the sense of self and a union with something larger than oneself. (Newberg and d'Aquili, p. 101) Additionally, there is often a sense of submission to a higher power, in which one's personal desires and fears are subordinated to the purposes of that higher power. If that higher power were identified with the leaders of a military hierarchy, it is easy to see how such experiences could be used to increase one's loyalty and submission to that hierarchy.

Wilson (2002) has proposed that the capacity for religion has evolved among humans as the result of selection at the level of groups, rather than individuals. Specifically, he argues that benefits that accrue to groups as the result of individual sacrifices can result in increased group fitness, and this can explain what is otherwise difficult to explain: religiously motivated behaviors (such as celibacy and self-sacrifice) that apparently lower individual fitness as they benefit the group.

At first glance, Wilson's argument seems compelling. Consider the most horrific manifestation of religious warfare: the suicide bomber. A person who blows him or herself up in order to kill his or her opponents has lowered his or her individual fitness. Doesn't this mean that such behavior must be explainable only at the level of group selection? Not at all: the solution to this conundrum is implicit in the basic principles of population genetics. Recall that one of Darwin's requirements for evolution by natural selection was the existence of variation between the individuals in a population. (Darwin, 1859, pp. 7 - 59) Variation within populations is a universal characteristic of life, an inevitable outcome of the imperfect mechanism of genetic replication. Therefore, it follows that if the capacity for religious experience is an evolutionary adaptation, then there will be variation between individuals in the degree to which they express such a capacity.

Furthermore, it is not necessarily true that when an individual sacrifices his or her life in the context of a struggle, the underlying genotype that induced that sacrifice will be eliminated by that act. Hamilton's principle of kin selection (Hamilton, 1964) has already been mentioned as one mechanism, acting at the level of individuals (or, more precisely, at the level of genotypes), by which individual self-sacrifice can result in the increase in frequency of the genotype that facilitated such sacrifice. Trivers (1971) has proposed a mechanism by which apparently altruistic acts on the part of genetically unrelated individuals may evolve by means of reciprocal altruism.

Given these two mechanisms, all that is necessary for the capacity for religious behavior, including extreme forms of self-sacrifice, to evolve is that as the result of such behaviors, the tendency (and ability) to perform them would be propagated throughout a population. The removal of some individuals as the result of suicide would merely lower the frequency of such tendencies and abilities in the population, not eliminate them altogether. If by making the ultimate sacrifice, an individual who shares his or her genotype with those who benefit by that sacrifice will, at the level of his or her genes, become more common over time. (Wilson, 1975, p. 4)

Let us now consider the flip side of war: the benefits that accrue to the winners of warlike conflicts. Given the mechanisms of kin selection, one can see how warfare and the religious beliefs that facilitate it might evolve among the closely related kin groups that constitute the raiding parties characteristic of hunting/gathering and pastoral peoples. It is also possible to construct an explanation for militia warfare and professional warfare on the basis of a blend of kin selection and reciprocal altruism. However, a closer examination of the spoils of war make such explanations relatively unnecessary.

Betzig (1986) performed a cross-cultural analysis of the correlation between despotism and reproductive success in 186 different cultures. Her conclusion was that "…[n]ot only are men regularly able to win conflicts of interest more polygynous, but the degree of their polygyny is predictable from the degree of bias with which the conflicts are resolved. Despotism, defined as an exercised right to murder arbitrarily and with impunity, virtually invariably coincides with the greatest degree of polygyny, and presumably, with a correspondingly high degree of differential reproduction." (Betzig, 1986, p. 88) In other words, males who most successfully use violence and murder as a means of influencing the actions of others have historically had the most offspring. In the context of warfare, this means that the winners of a battle, or even more so, of a war will pass on to their offspring whatever traits facilitated their victory, including the capacity to believe in a supernatural force that guides their destiny and protects them in battle. The effects of such capacities are not trivial; as Betzig points out, the differences between the reproductive success of the winners of violent conflicts and the losers is measured in orders of magnitude. As noted earlier, wars are bottlenecks through which only a relative few may pass, but which reward those who do with immensely increased reproductive success.

Putting all of this together, it appears likely that the capacity for religious experience and the capacity for warfare have constituted a coevolutionary spiral that has intensified with the transitions from a hunting/gathering existence through subsistence agriculture to the evolution of the modern nation-state. As pointed out earlier, there is a correlation between the type of intergroup violence and the ecological context within which that violence occurs. Generally speaking, raiding/rustling is correlated with hunting/gathering and pastoralism, militia warfare with village agriculture, and professional warfare with urban society and the nation-state. There is a corresponding progression in the basic form of religious experience and practice: animism is most common among hunter-gatherers, while polytheism is more common among agriculturalists, and monotheism is most common in societies organized as nation-states. This is not to say there are no exceptions to this correlation. However, the fact that such a correlation can even be made points to the underlying ecological dynamics driving the evolution of subsistence patterns, patterns of warfare, and types of religious experience.

REFERENCES CITED

Betzig, L. (1986). Despotism and differential reproduction: A darwinian view of history. New York: Aldine.

Darwin, C. R. (1859). On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: Murray.

Hamilton, W. D. (1964). The genetical theory of social behavior. Journal of theoretical biology, 12(1), 1-52.

Newberg, A. B. and d'Aquili, E. G. (2001). Why god won't go away: Brain science and the biology of belief. New York: Ballantine.

Trivers, R. L. (1971). The evolution of reciprocal altruism. Quarterly review of biology, 46(4), 35-57.

Wilson, D. S. (2002). Darwin's cathedral: evolution, religion, and the nature of society. Chicago: University of Chicago Press.

Wilson, E. O. (1975). Sociobiology: The new synthesis. Cambridge, MA: Belknap.

--Allen

Read More

Natural Selection, Sparrows, and a Stochastic God

AUTHOR: Allen D. MacNeill

SOURCE: Original essay

COMMENTARY: That's up to you...

A priest and a nun are out playing golf; that is, he's playing, and she's carrying his clubs. The priest tees off, and slices his ball into the rough. "Damn." he says. The nun upbraids him, saying that the Lord God forbids such profanity. The priest trudges over to his ball, addresses it with a mashie-niblick, and hooks it across the fairway into the trees on the other side. "Damn!" he says again, and again the nun upbraids him. He searches for the ball among the trees, finally finding it in the underbrush. He smacks it once again, clearing the rough, but landing in a bunker just short of the green. "Damn!" he says once again, and now the nun dogs him to the sand trap, chewing him out for his repeated blasphemy. As he steps up to the ball, now nestled in a deep crater in the sand, the nun tells him that if he uses profanity one more time, the Lord God will surely smite him. Then she hands him his sand wedge.

He whacks the ball again, blasting it through a cloud of sand across the green and into the bunker on the other side. "Damn, damn, DAMN!" he shouts, and of course the nun lays into him, warning him of the imminence of Hellfire. Suddenly, there is an incandescent blast of purple lighting and an explosion of thunder...and the nun is instantly reduced to a pile of smoking cinders beside the priest. And from out of the rumble of thunder in the sky, an immense and overwhelming voice in the clouds (in a deep basso profundo) says "DAMN!"

Why is this joke funny (at least to some people)? One reason might be the incongruity of a priest and a nun playing golf. Another reason some find it funny is that the nun "gets what's coming to her." Furthermore, the priest gets away with his blasphemy, and at the expense of the nun. But funniest of all (in a way that may also send a slight shiver up the spine) is the idea that God's aim is as bad as the priest's.

Why does this last implication raise the hackles? Because it implies that God is a stochastic agent; He aims, but sometimes misses. A stochastic process (from the Greek stochos, meaning "a target") is any process that includes a random component; one aims at a target, but doesn't always hit it in the gold. In other words, a stochastic process is a probabilistic process, rather than an entirely determined one - there is a small, but irreducible probability that one will miss the target.

According to many who profess belief in the Western (i.e. Judeo-Christian-Muslim, or "JCM") concept of God, the idea that God operates stochastically is anathema. God is, according to this tradition, omnibenevolent ("all good"), omniscient ("all-knowing"), omnipotent ("all powerful"), and omnipresent ("present everywhere and everywhen"). To paraphrase Matthew 10:29, "not a sparrow falls, but that Thou art mindful of it." Even Albert Einstein, certainly not a believer in the mainstream JCM concept of God, believed that "God does not play dice."[1] An omnibenevolent, omniscient, omnipotent, omnipresent deity (call Him the "omni God") is ultimately responsible for all events in the universe, at all times and in all places.

Humor, according to Aristotle (among others), can arise from the juxtaposition of two mutually exclusive ideas. This is one of the sources of the humor in the "golfing God" joke - the God who aims at the priest but blasts the nun is not omnipotent. Funny, but perhaps not so funny, if one is a Christian Fundamentalist, or anyone who holds a belief in the existence of an omni God. To a Fundamentalist, the belief that their omni God "never misses" is a basic article of faith; an axiom, if you will.

Which brings me to the main point of this essay: the majority of soi-disant "creation scientists" (CS) accept the observable fact that natural selection happens. Indeed, natural selection (of a very limited sort) is absolutely necessary for most theories of "creation science." Rather than driving the characteristics present in a population of organisms away from the population mean and toward some new equilibrium state (i.e. an adaptation, according to evolutionary theory), natural selection operates to maintain the "created kind" or "type" of each species by means of "stabilizing selection." That is, all deviations from the original "created kind" are winnowed away, leaving the supernaturally specified "kind."

The new breed of creation scientists, those who devise and promulgate theories of "intelligent design," are believers in the same underlying idea: that an "intelligent designer" (identity usually unspecified...at least, in public) guides the evolution of groups all living organisms via some (also unspecified) quasi-magical means. Natural selection is also integral to their ID theories, but again it is resolutely not the source of "specified complexity" - the exquisite adaptations of living organisms to the contingencies of their environments. In ID theory, as in the older (and perhaps more intellectually honest) theories of "creation science," the only genuine function of natural selection is to "fix" the various characteristics of organisms within an "adaptive landscape" whose topography is specified essentially by an intelligent designer (i.e. an omni God).

But there's the rub: to believe the foregoing is perforce to believe that God "misses:" that He specifies the characteristics of organisms within an intentional boundary, but allows individuals to deviate sufficiently from that boundary that they...well, not to put too fine a point on it, they die (or fail to reproduce, which is effectively the same thing). This is the essence of stabilizing selection: although there are deviations from the population mean, such deviants are eliminated, thereby maintaining the population mean in perpetuity. To paraphrase Darwin, out of "famine and death," the creationist/ID "kinds" are specified and maintained.[2]

That would be scanned: a deity kills the deviants, and for that, He does the survivors maintain in perpetuity? Surely not impossible for an omni deity, but just as surely a fundamental contradiction in terms. To operate in such a fashion, this deity must be a utilitarian, whose intention (yes, intentions are essential to the argument) is to specify the ideal "kind" by first creating (or at least "specifying") a range of no-so-ideal individuals, and then mercilessly (even mindlessly?) eliminating all but the few that conform to the intended ideal. True, a lot of sparrows thereby "fall," and in the CS/ID version of this explanation, the JCM God is indeed "mindful" of them, at least insofar as He creates them in order to destroy all but a few of them.

And not just sparrows; most if not all intelligent design theorists (such as Michael Behe, William Dembski, Phillip Johnson, et al) willingly embrace the idea that natural selection operates upon humans. They just don't believe that it can possibly specify all of the complex attributes of humans. So, by the logic heretofore developed, ID theorists willingly embrace a utilitarian, stochastic deity who intentionally designs humans with sufficient genetic and developmental plasticity that some (the exact proportion is irrelevant) deviate from the population mean, and then causes them (indirectly or directly, it matters not) to suffer and die, in order to bring about and maintain that paragon of animals - ourselves.

Fundamentalists, creation scientists, intelligent design theorists, and their fellow travelers are therefore stuck. If they accept the operation of natural selection at any level, they must perforce accept that God (or the unidentified "Intelligent Designer") is a fundamentally stochastic entity, who of necessity obliterates the occasional nun and creates a skyfull of falling sparrows, an entity who is manifestly not omnibenevolent, omnipotent, omniscient, nor omnipresent, but is a utilitarian whose ends justify His means. Or, they must deny the operation of natural selection at any level; in other words, they must stare reality in the face and deny it. Either those individuals who deviate from the specified population mean are created in order to die, or they die by accident...they fall, and while He may be mindful, He just doesn't give a damn.

**********************************************************************************
NOTES:

[1] Einstein, A. (1926) Letter to Max Born: "God does not play dice with the universe."
URL: http://en.wikipedia.org/wiki/Max_Born

[2] Darwin, C. (1859) On the Origin of Species By Means of Natural Selection. John Murray, London, England. Ch. 14, pg. 490 URL: http://pages.britishlibrary.net/charles.darwin/texts/origin1859/origin14.html

**********************************************************************************
AUTHOR'S' BIOGRAPHICAL & CONTACT INFORMATION:

Allen D. MacNeill
adm6@cornell.edu

**********************************************************************************

Read More

Scientists Force Evolution in the Lab

AUTHOR: Robert Roy Britt

SOURCE: LiveScience.com

COMMENTARY: Allen MacNeill (following text of article)

Scientists have forced a little evolution in the laboratory, controlling whether a caterpillar becomes green or black.

The color of the critter was made to vary with temperature during their development. The experiment reveals the basic hormonal mechanism underlying the evolution of such dual traits, the researchers report in the Feb. 3 issue of the journal Science.

The study was done on Manduca sexta, a caterpillar commonly called the tobacco hornworm. Its larvae are normally green. A related species, Manduca quinquemaculata, becomes black or green depending on temperature. The idea was to use similar temperature shocks to evolve a similar change in M. sexta.

Differing color traits induced by environmental factors are called polyphenisms.

Similar differences show up in genetically identical ants, which can develop into queens, soldiers, or workers based on the hormones they're exposed to early in development. Similar hormonal differences can affect the specific color of a butterfly or bird.

Scientists have not understood evolution's exact role in the differences.

"There had been theoretical models to explain the evolutionary mechanism -- how selective pressures can maintain polyphenisms in a population, and why they don't converge gradually into one form or another," said Duke University graduate student Yuichiro Suzuki. "But nobody had ever started with a species that didn't have a polyphenism and generated a brand-new polyphenism."

Suzuki and biology professor Frederik Nijhout worked with black mutants of the normally green M. sexta. The mutants have a lower level of a key hormone.

The scientists subjected the black mutants to temperatures above 83 degrees Fahrenheit, and over a few generations two types developed. One group turned green and the other didn't.

Importantly, the two groups were found to have distinctly different levels of the hormones.

They then found that they could create green spots on black caterpillars by applying drops of the hormones at the right stage of development. And by thwarting the flow of hormones from head to body—they applied a little caterpillar tourniquet—they could prevent the greening.

None of this looks to be going anywhere in the sense of survival of the fittest. The black and green caterpillars will all grow up basically the same.

"The adult moths are identical, and so there is no obvious basis for the kind of selective mating that might genetically isolate two groups and eventually lead to new species," Nijhout told LiveScience. Because the variations are based on temperatures, and thus in the wild would be dependent on seasons, the two types would tend to occur at different times of the year and may never meet in nature, he said.

The next step, the researchers said, is to see if the variations do indeed occur in the wild.

**********************************************************************************
AUTHOR'S' BIOGRAPHICAL & CONTACT INFORMATION:

Robert Roy Britt is the Managing Editor for LiveScience.com

**********************************************************************************
COMMENTARY:

This appears to be an interesting, if somewhat limited experiment. Selection for the green morph of the black mutant using high temperatures could mimic what might happen in the event of global warming, especially given the normal range of Manduca sexta.

But, the author of this Live Science article makes a profoundly dumb statement:

None of this looks to be going anywhere in the sense of survival of the fittest. The black and green caterpillars will all grow up basically the same.

Except that selection can operate on the larval stage just as easily as on the adult stage, especially if the dark mutant is more visible to predators. By analogy with American rat snakes, it seems likely to me that the dark mutants (which are expressed at cooler temperatures) may gain a selective advantage by absorbing more sunlight, thus warming them more quickly in the early morning when their leaf food supply is at its highest nutritional content, whereas the green morph would be more cryptic. In other words, which morph is selected for depends on several interacting environmental factors, including ambient temperature and the presence of avian predators.

Indeed, this experiment is right in line with Mary Jane West-Eberhard's work on evolutionary developmental biology ("evo-devo"). Selection on early developmental stages, such as these larvae, can cause rather dramatic changes in a relatively short time (i.e. "a few generations," as described in the article). Furthermore, the results indicate that polyphenisms (i.e. polymorphisms) can be generated and maintained without necessarily requiring the kinds of genetic mechanisms specified by R. A. Fisher and other population geneticists of the "modern evolutionary synthesis." That is, these experimental results provide evidence for a new paradigm for phenotypic variation, supporting evo-devo and transcending the "modern synthesis."

Now, an "intelligent design theorist" might argue that this doesn't really show anything, as the underlying genetic predisposition for the green color morph was probably already present in the Manduca sexta, and was simply "turned on" by prolonged exposure to heat. That is, no new "complex specified information" was produced as the result of selection.

Well, that kind of response would be essentially irrelevant to the evolutionary implications of this experiment. What Nijhout and Co. have shown is that dramatic phenotypic changes can be induced as the result of selection for only a few generations, and that this can be correlated with the underlying hormonal physiology.

And besides, at least its an experiment, using real organisms and involving at least quasi-natural conditions. That is, it's light-years beyond the kind of intellectual masturbation typically performed by the average "intelligent design theorist," who declines to stoop to trivialities like empirical verification or publication in peer-reviewed mainstream scientific journals.

--Allen

**********************************************************************************
ORIGINAL PUBLICATION REFERENCE:

LiveScience.com
URL: http://news.yahoo.com/s/space/20060202/sc_space/scientistsforceevolutioninthelab

Original posting/publication date timestamp:
Thu Feb 2, 3:00 PM ET

**********************************************************************************

Read More