General 24 Jun 2011 05:22 pm

Teleological Explanations in Biology

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Biologists tend to use teleological language in explaining the origin and evolution of living organisms and their characteristics. As John Reiss has pointed out (Reis, J. Not by Design: Retiring Darwin’s Watchmaker, University of California Press, 2009), this entails the idea that evolution is necessarily a teleological process. This entails the idea that evolution is not a “natural” process, like gravity or oxidation, and that therefore there is some “non-natural” component (i.e. “magic”) in biology that fundamentally distinguishes it from the other natural sciences.

Evolutionary biologists like Richard Dawkins try to make this distinction when referring to the problem of human free will (see “Let’s all stop beating Basil’s car”), but unless they are careful about how they talk about evolution (especially natural selection) they revert to the same teleological descriptions and explanations that Reiss so decries. What is the problem, here?

I believe that the underlying problem is the tendency by most evolutionary biologists to think of natural selection as a “force” or “mechanism”. As John Endler has pointed out (Endler, J. Natural Selection in the Wild, Princeton University Press, 1986), natural selection is not a “force” or “mechanism”, it is an outcome. To be precise, it is the outcome of four separate, but related processes:

Variety: structural and functional differences between individuals in populations,

Heredity : the inheritance of structures and functions from parents to offspring (either genetically or epigenetically),

Fecundity : the ability to reproduce, especially (but not necessarily) at a rate that exceeds replacement, and

Demography : some individuals survive and reproduce more often than others.

As a result of these four processes, the heritable characteristics of some individuals become more common in populations over time.

Notice that the same list of processes can be used to explain non-adaptive evolutionary change (e.g. genetic drift). Also notice that the only source of new phenotypic variations is what I have called the “engines of variation“: all of those processes that produce heritable phenotypic changes in phylogenetic lines of organisms in populations. There are at least fifty such processes (you can see a summary list here). While it is the case that “random mutation” is included in this list, there are many other processes in this list that do not involve “mutation” (in the genetic sense) and which also are not “random” (at least insofar as that term is often used).

Is there a real distinction between non-teleological and teleological processes, or are all processes either teleological or not? If all processes (i.e. changes over time) are teleological, as asserted by Aristotle (and some of the commentators), then there is no point in talking about it. However, if some processes are teleological and some are not (as most people, including presumably most of the commentators here, now believe), then the question becomes “how can one distinguish between teleological and non-teleological processes, and what explains the differences between them?”

In his comprehensive analysis of teleology, Andrew Woodfield (Woodfield, A. Teleology, Cambridge University Press, 1976) pointed out that all teleological descriptions can be reformulated to conform to the linguistic formula ” x happens in order to/for y outcome.” He also asserted that such linguistic formulations describe metaphysically real processes. That is, some processes are genuinely teleological – they involve pre-existing designs or plans that cause processes to tend toward particular outcomes, regardless of perturbations or outside interference – while other processes only seem teleological – they involve laws of nature, such as gravity, that result in particular outcomes, without responding actively to perturbations or outside interference.

This distinction is essential when considering whether “genuine” teleology exists. To be precise, teleological descriptions sound “reasonable” when they are applied to genuinely teleological processes, but sound ridiculous if they are applied to non-teleological processes. For example, does it sound reasonable to say that when you drop a rock, it falls “in order to” reach the ground? By contrast, does it sound reasonable to say that birds have wings “in order to” fly? Is there a difference between the “reasonableness” of the first teleological explanation and the second?

When I pose this question to my students, almost all of them say yes: the first is ridiculous and the second isn’t. I then point out that this implies that the origin of the wings of birds therefore seems to be the result of a teleological process. I then point out (reprising Aristotle) that there are at least four ways of explaining the presence of wings:

• “this bird has wings because it is composed of materials that are assembled and operated as wings” (Aristotle’s “material” cause);

• “this bird has wings because its parents had wings” (Aristotle’s “efficient” cause);

• “this bird has wings because birds have wings” (Aristotle’s “formal” cause); and

• “this bird has wings in order to fly” (Aristotle’s “final” cause).

Since at least the 17th century (and mostly because of Newton), natural scientists have stopped using formal or final causes to explain natural phenomena…except in biology. This was first pointed out by Colin Pittendrigh (Pittendrigh, C. S. Behavior and Evolution) (ed. by A. Rose and G. G. Simpson), Yale University Press, 1958), who coined the term “teleonomy” to refer to the kind of teleological phenomena observed in biological processes. Francisco Ayala modified and extended Pittendrigh’s analysis (Ayala, F. J. ‘Teleological Explanations in Evolutionary Biology’, Philosophy of Science, vol. 37 pp. 1-15, 1970). Ernst Mayr finally sorted the whole thing out in 1974 in “Teleological and teleonomic: A new analysis” (Boston Studies in the Philosophy of Science, vol. XIV, pp. 91 -117). According to Mayr, the difference between the “behavior” of dropped rocks and genuinely purposeful processes is the presence or operation of a pre-existing information-containing program in the latter. Rocks do not fall because there is an encoded program in nature that makes them fall. They fall because there is a force (i.e. a law of nature) that causes them to fall. However, a bird has wings because there is a program encoded within its genome which, as the result of interactions between the “phenome” of the bird and its environment, causes the construction and operation of wings.

To say that natural selection is teleological would therefore require that there be a pre-existing encoded program somewhere that would cause natural selection to bring about its effects. This is ridiculous for at least two reasons:

• there is no such program as far as we can tell (where would it be encoded?), and

• this would require that natural selection be a process in and of itself, rather than the outcome of the four processes listed above.

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

Allen

General 24 Jun 2011 03:59 pm

The Metaphysical Foundations of Modern Science

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I started attending the weekly meetings of the Ithaca Friends Meeting in September, 1969. One of the people who made an immediate and lasting impression on me was an older gentlemen, always impeccably dressed, who sometimes spoke in meeting in a quavery, but very determined voice. His “messages” were always very literate, but not necessarily complicated. I was eventually introduced to him, and learned that his name was “Ned” Burtt, and that he was one of the founders of the Ithaca meeting.

After several years we became good friends, but only in the context of the Friends Meeting. I got to know his wife, Marjory, with whom I had many very engaging conversations. She was a retired psychotherapist with an interest in Eastern philosophy, especially Buddhism. I didn’t have as many conversations with Ned, not because he wasn’t willing, but because he was almost completely deaf. Indeed, after a few years I noticed that Marjory and some of his older friends took turns sitting next to him in meeting, and when someone rose to speak, would write down what they said on a slip of paper and pass it to Ned.

Year later I was co-teaching a course on the history and philosophy of science, for which the teaching staff had chosen as one of the required readings a “classic” in the history of science, The Metaphysical Foundations of Modern Science, by Professor Edwin Arthur Burtt, the Susan Lynn Sage Professor of Philosophy at Cornell University. Translated into dozens of languages and continuously in print since 1924, Burtt’s Metaphysical Foundations was often mentioned as the precursor to Thomas Kuhn’s The Structure of Scientific Revolutions, and one of the seminal texts in the history of science.

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Imagine my surprise (and chagrin) when I discovered that “Ned” Burtt of the Ithaca Friends Meeting was Prof. Edwin Arthur Burtt himself, author of the Metaphysical Foundations and perhaps the most famous historian of science in the first half of the 20th century. Characteristically, he never mentioned it in any of our conversations (brief and halting as they were), and no one else in meeting seemed to think it important enough to mention either.

Ned died in 1989 at the age of 97, and was memorialized at the Ithaca Meeting in our usual way – a silent meeting, punctuated by a few heart-felt “messages” from his friends. I think of him now as I am re-reading once again his Metaphysical Foundations, and am once again struck by his keen insight and masterful use of language. Here’s just one sample:

“The glorious romantic universe of Dante and Milton, that set no bounds to the imagination of man as it played over space and time, had now been swept away. Space was identified with the realm of geometry, time with the continuity of number. The world that people had thought themselves living in – a world rich with colour and sound, redolent with fragrance, filled with gladness, love and beauty, speaking everywhere of purposive harmony and creative ideals – was crowded now into minute corners in the brains of scattered organic beings. The really important world outside was a world hard, cold, colourless, silent, and dead, a world of quantity, a world of mathematically computable motions in mechanical regularity. The word of qualities as immediately perceived by man became just a curious and quaint minor effect of that infinite machine beyond. In Newton the Cartesian metaphysics, ambiguously interpreted and stripped of its distinctive claim for serious philosophical consideration, finally overthrew Aristotelianism and became the predominant world-view of modern times.

*Whew* - talk about a splash of cold water in the face. It is this world-view – the one that forms the basis of all of modern science, including biology – that depresses and terrifies those who cannot live without the “old magic” and motivates those who want to tear down “modern” science and go back to the pre-scientific world-view, what Carl Sagan called “the demon-haunted world.” But, just like the magic realm of childhood, there is no going back now, not to the innocent and often terrifying universe of the childhood of our cultures. In the words of Bertrand Russell (one of Ned Burtt’s contemporaries):

“That Man is the product of causes which had no prevision of the end they were achieving; that his origin, his growth, his hopes and fears, his loves and beliefs, are the outcome of accidental collections of atoms…that all the labours of the ages, all the devotion, all the inspiration, all the noonday brightness of human genius, are destined to extinction in the vast death of the solar system, and that the whole temple of Man’s achievement must inevitably be buried beneath the debris of a universe in ruins…only on the firm foundation of unyielding despair can the soul’s habitation henceforth be safely built.” – A Free Man’s Worship [1923]

And so tomorrow (it’s Memorial Day once again), I will go walking through the little grave yard out behind the Hector Meeting House where Ned and Marjory are buried, and think once again about the old, deaf gentleman whose messages were so eloquent and whose view of reality so unflinching.

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

Allen

General 24 Jun 2011 03:44 pm

Evolutionary Psychology: The Science of Human Nature

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Having been tickled by Google Alert that my name had been mentioned in the comments at Pharyngula (P. Z. Myer’s blog), I took a quick look. Just a few comments for now:

1) I became an evolutionary psychologist when studying the behavioral ecology of Microtus pennsylvanicus got boring. Those cute little field voles got boring because their ethology is relatively simple. Human ethology is a lot more interesting, mostly because it is a lot more complex. Should we not try to study it because it is more complex? Or because it might not jibe with some people’s political preconceptions?

2) I assign Gould & Lewontin’s “spandrels” paper to my students in evolutionary biology, along with various criticisms of it. I also assign Eldredge & Gould’s “punk eek” paper and Gould and Vrba’s “exaptation” paper (along with close to three dozen others, not to mention the entire Origin of Species, 1st. ed.). I also give them chunks of George William’s 1966 classic, Adaptation and Natural Selection, so that they will know exactly how “onerous” the concept of “adaptation” actually is.

3) Here’s the definition of “adaptation” I use:

An evolutionary adaptation is any heritable phenotypic character whose frequency of appearance in a population is the result of increased reproductive success relative to alternative versions of that heritable phenotypic character.

4) Here are the criteria I believe are most useful when one is attempting to determine if one is dealing with an “adaptation”:

• Qualification 1: An evolutionary adaptation will be expressed by most of the members of a given population, in a pattern that approximates a normal distribution;

• Qualification 2: An evolutionary adaptation can be correlated with underlying anatomical and physiological structures, which constitute the efficient (or proximate) cause of the evolution of the adaptation;

• Qualification 3: An evolutionary adaptation can be correlated with a pre-existing evolutionary environment of adaptation (EEA), the circumstances of which can then be correlated with differential survival and reproduction; and

• Qualification 4: An evolutionary adaptation can be correlated with the presence and expression of an underlying gene or gene complex, which directly or indirectly causes and influences the expression of the phenotypic trait that constitutes the adaptation.

To me, it seems reasonable that if one can apply those to a specific human behavior, one can make arguments about its evolutionary derivation. Would anyone disagree? As for the ridiculous idea that evolutionary psychology only deals with sex, has anyone making such a claim actually read a textbook on the subject? Here are several:

Human Evolutionary Psychology

Evolutionary Psychology: The New Science of the Mind (4th Edition)

Evolution and Human Behavior, 2nd Edition: Darwinian Perspectives on Human Nature

Evolutionary Psychology: The Science of Human Nature

[Full Disclosure Notice: The fourth title is indeed by Yours Truly.]

If you haven’t, then please do so, and then we can discuss these questions. While we’re on the subject, Part II of Evolutionary Psychology: The Science of Human Nature (on the ethology of between-group behavior in humans) is coming out in September of 2011. My next project is an introductory textbook in evolutionary biology, entitled Evolutionary Biology: The Darwinian Revolutions, again in two parts. Part I (due out in September) is The Modern Synthesis and Part II (due out next May) is The Evolving Synthesis. After that (if I live that long) will be On Purpose: The Evolution of Design by Means of Natural Selection (won’t there be some fireworks when that comes out?), in which I present one of the core arguments for The Metaphysical Foundations of the Biological Sciences, in the spirit of E. A. Burtt’s The Metaphysical Foundations of Modern Physical Science. Should be fun!

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

Allen

General 06 Jun 2010 06:07 pm

The Annotated Origin of Species

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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.

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

Allen

General 25 Apr 2010 06:22 am

Evolution and Free Will: Is Free Will an Illusion?

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Every summer I teach a seminar course at Cornell in which we examine the historical, philosophical, religious, and scientific implications of evolutionary theory. This summer our seminar course will once again consider the question: Is free will an illusion?

On the 15th of July, 1838, Charles Darwin began a notebook which he labeled as “M”, in which he intended to write down his correspondence, discoveries, musings, and speculations on “Metaphysics on Morals and Speculations on Expression”. On page 27 of that notebook, he wrote

“…one doubts existence of free will every action determined by hereditary constitution, example of others or teaching of others. (…man…probably the only [animal] affected by various knowledge which is not heredetary & instinctive) & the others are learnt, what they teach by the same means & therefore properly no free will. [Emphasis added]

In his private musing on the question of free will, Darwin came to the conclusion that human free will is an illusion, and that all of our actions (and, by extension, our thoughts and intentions) are the result of our “hereditary constitution” and “the example…or teaching of others.” Some evolutionary biologists, notably William Provine of Cornell University, have followed Darwin’s lead and asserted that human free will is an illusion. Most philosophers disagree, asserting that free will is the principle difference between humans and non-human animals. Many Christian theologians go further, asserting that free will is the foundation of all human action, without which no rational ethics or theology is possible.

In our seminar course this summer we will take up this debate by considering two alternative hypotheses: (1) that human free will is real and can provide a basis for our morals and ethics, or (2) that human free will is an illusion, the capacity for which is a product of the same evolutionary processes that have shaped our anatomical and behavioral adaptations. Included in this debate will be an extended consideration of the hypothesis that the capacity for ethical decision making is an evolutionary adaptation that has evolved by natural selection. We will read from some of the leading authors on both sides of the subject, including George Ainslie, Daniel Dennett, Robert Kane, William Provine, Daniel Wegner, and Edward O. Wilson. Our intent will be to sort out the various issues at play, and to come to clarity on how those issues can be integrated into a perspective of the interplay between philosophy and the natural sciences. Here are some particulars for the course:

INTENDED AUDIENCE: This course is intended primarily for students in biology, history, philosophy, religious studies, and science & technology studies. The approach will be interdisciplinary, and the format will consist of in-depth readings across the disciplines and discussion of the issues raised by such readings.

PREREQUISITES: None, although a knowledge of general evolutionary theory, evolutionary psychology, sociobiology, and the philosophy of human free will would be useful.

DAYS, TIMES, & PLACES: The course will meet on Tuesday and Thursday evenings from 6:00 to 9:00 PM in Mudd Hall, Room 409 (The Whittaker Seminar Room), beginning on Tuesday 29 June 2010 and ending on Thursday 5 August 2010.

CREDIT & GRADES: The course will be offered for 4 hours of credit, regardless of which course listing students choose to register for. Unless otherwise noted, course credit in BIOEE 4670 / BSOC 4471 can be used to fulfill biology/science distribution requirements and HIST 4150 / STS 4471 can be used to fulfill humanities distribution requirements (check with your college registrar’s office for more information). Letter grades for this course will be based on the quality of written work on original research papers written by students, plus participation in class discussion. All participants must be registered in the Cornell Six-Week Summer Session to attend class meetings and receive credit for the course (click here for for more information and to enroll for this course). Registration will be limited to the first 18 students who enroll for credit.

REQUIRED TEXTS:

Ainslie, G. (2008) Breakdown of Will, Cambridge University Press, ISBN: 0521596947 (paperback: $34.99), 272 pages.

Dennett, D. (2004) Freedom Evolves, Penguin Books, ISBN: 0142003840 (paperback: $17.00), 368 pages.

Kane, R. (2005) A Contemporary Introduction to Free Will, Oxford University Press (USA), ISBN: 019514970X (paperback: $19.95), 208 pages.

Wegner, D. (2003) The Illusion of Conscious Will, MIT Press, ISBN-10: 0262731622 (paperback: $21.95), 419 pages.

Wilson, E. O. (2004) On Human Nature (Revised Edition), Harvard University Press, ISBN: 0674016386 (paperback: $22.00), 284 pages.

OPTIONAL TEXTS:

Darwin, Charles (E. O. Wilson, ed.) (2006) From So Simple a Beginning: Darwin’s Four Great Books. W. W. Norton, ISBN-10: 0393061345 (hardcover, $39.95), 1,706 pages. Available online here.

Fisher, J., Kane, R., Pereboom, D., & Vargas, M. (2007) Four Views on Free Will, Wiley-Blackwell, ISBN: 1405134860 (paperback: $33.95), 240 pages.

Kane, R. (2001) Free Will (Blackwell Readings in Philosophy), Wiley-Blackwell, ISBN: 0631221026 (paperback: $33.95), 328 pages.

Wilson, E. O. (2000) Sociobiology: The New Synthesis (25th Anniversary Edition), Belknap Press, ISBN: 0674002350 (paperback: $44.00), 720 pages

Our summer seminar course is always fascinating, and often quite controversial (see this and this). Over the years we have explored many of the implications of Darwin’s theory, and the participants have always found our discussions (perhaps they should be called “debates”) enlightening. As always, the intent is not necessarily to reach unanimity, but rather for each participant to come to clarity on where they stand on the issues and to be able to defend that stance using evidence and rational argument.

So, please consider taking our seminar on free will this summer - the choice is yours!

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

Allen

General 24 Mar 2009 04:26 am

Analogy, Metaphor, and Inference in Science

Mike Gene, the pseudonymous founder of Telic Thoughts and the author of The Design Matrix: A Consilience of Clues has written the following about metaphors and their application to the detection of intelligent design:

Metaphors such as “fear”, “cost”, “abhor” and “angry”, commonly share the projection of consciousness onto the world. Metaphors such as these represent the human tendency to view the world through anthropomorphic glasses. However, the metaphors employed by molecular biologists are not of this type.

Metaphors typically break down when we begin to take them literally.

[but] The design terminology that is used in the language of molecular biology does not break down when interpreted literally

[T]here is a basic and literal truth to the use of design terminology in molecular biology–these technological concepts are just too useful. Metaphors are certainly useful when explaining concepts to other human beings, yet the design terminology often goes beyond pedagogy–it provides true insight into the molecular and cellular processes. An understanding of our own designed artifacts, along with the principles required to make them, can guide the practice of molecular biology.

Metaphors are a special case of analogies (the other being similes). I have written extensively on the subject of the use of analogies and metaphors in science, and especially in the evolution/design debate here, here, and here. The fundamental question in this ongoing debate is, how do we know an analogy really exists? For example, do we have any objective way to determine if one rock is analogous with another? Or whether an anatomical feature (or a protein/substrate binding site) is analogous to another?

As in the case of agency detection, we think we can do this very easily (just as we can easily identify what looks like design), but I would argue that this is because both “finding” analogies and “finding” design and purpose are capabilities of the human mind (and the nervous system that supports it) that have conferred enormous adaptive value on our ancestors. As in the case of our hypothesized “innate agency/design/purpose detector” (which first becomes active in very early infancy), our “analogy detector” also appears to become active at a very early age, and operates entirely in the background. That is to say, we are almost totally unaware of its operation, and concentrate only on its output.

Our ability to detect (and construct) analogies is, IMO, the core of our intelligence, as demonstrated by the fact that identifying analogies has been traditionally used as one of the most sensitive gauges of general intelligence in intelligence tests (such as the Miller Analogies Test).

In the context of Mike Gene’s ideas about metaphors, doing engineering (and especially mathematics) is essentially the construction of highly compact analogies, in which numerical (and sometimes physical) relationships are expressed in the form of abstract symbols. A blueprint is simply a metaphor for a building, just as a chemical formula is a metaphor for the product of the chemical reaction, and a recipe for a cake is a metaphor for the cake. Indeed, many mathematical relationships (especially in the natural sciences) are expressed as equations, which are quite literally metaphors expressed in symbolic form. For example, Newton’s equation for force:

F = ma

is a metaphor linking the concept of force with the concepts of mass and acceleration.

In molecular biology we encounter once again the concept of metaphors, for what is the genome of an organism but a highly abstract metaphor for the fully embodied and operating organism itself? I agree with those (and I expect Mike Gene would number himself among them) who assert that the encoding of “life” into a string of nucleotides is indeed the crucial difference between biological “metaphors” and physical “direct necessities”. Gravity isn’t “encoded” in anything, but proteins are, and so are cells, tissues, organs, organ systems, organisms, and (at least at some level) their behaviors.

So, is there a way to verify if an analogy or metaphor is “real”? In the case of some analogies in biological systems we have an independent double-check on our identification of analogies. This is based on the evolutionary concept of homology, or derivation from a common ancestor. If two structures on two different organisms (say a small bone of the jaw of a reptile and the even smaller bone in the middle ear of a mammal) appear to be analogous (on the basis of size, location, relationship to other bones, etc.) there are at least two different, though related, methods of verifying that these structures are indeed analogous (and not just accidentally similar).

One way is by means of comparative paleoanatomy, in which a series of fossils of known age are compared to determine if there is a connection between the evolutionary pathways of derivation of the structures. If such a pathway can be empirically shown to exist, this would be strong evidence for both the analogous and homologous nature of the objects.

Alternatively one could compare the nucleotide sequences that code for the structures to determine if they are sufficiently similar to warrant a conclusion of homologous derivation. In both cases, evidence for homology, combined with our intuitive “identification” of analogous structure and/or function, both point to the same conclusion: that the two structures are both analogous and homologous.

This is why structures that appear to be analogous, but for which there is no convincing evidence of homology (as in the wings of birds and insects) can present a serious problem to evolutionary biologists, and especially those engaged in biological classification. Such apparent similarities (technically called homoplasies) can either be the result of “true” (i.e. partial) analogy at the functional (and/or structural) level (and therefore assumed to be the result of convergent evolution) or they can be completely accidental. Simple inspection is often insufficient to separate these two hypotheses, and lacking either fossil or genomic evidence, conclusions about the validity of such analogies can be extremely difficult to draw. However, if there is fossil and/or genomic evidence and it points away from homology (i.e. descent from a common ancestor), then the structures can be considered to be analogous, but not homologous.

One of the dangers in invoking analogies and metaphors is overusing the concept of analogy to mean almost anything. Indeed, it is essential in discussions such as these that we be as precise as possible about our definitions, as imprecision can only lead to confusion (at best) and unsupportable conclusions (at worst).

Perhaps the most essential distinction to be made in this regard is between “analogies of description” (which could also be called “semantic analogies”) and “analogies of function/structure” (which could also be called “natural analogies”). The former (i.e. “semantic analogies”) are merely artifacts of the structure of human cognition and language, as happens whenever we describe an analogy that we have perceived.

By contrast, the latter (i.e. “natural analogies”) are the actual similarities in function/structure that we are describing (i.e. that resulted in our identification and description in the first place). As in the Zen koan about the roshi and the novice in the moonlit garden, much of the confusion about which of the two types of analogies we are discussing seems to stem from confusion between the moon that illuminates the garden and the finger pointing at the moon.

In the brief example from Mike Gene’s The Design Matrix posted at the head of this thread, the implication is that the analogies we perceive between biological systems and those engineered by humans are “natural analogies”; that is, they are real analogies, and not simply a form of linguistic convenience. However, there is nothing about the finding of an analogy that necessarily verifies that the analogy is “natural” (i.e. “real”), as opposed to “semantic” (i.e. “imaginary”). This would be the case even if one found repeated analogies between complex systems engineered by humans and biological systems that evolved by natural selection. To verify that an analogy is “natural” requires an independent source of validation for the assertion that the analogy is “real” and not merely “semantic”. At this stage in my reasoning about this subject I am not at all sure how one would go about this.

However, one thing I am sure of is that simply asserting over and over again that one has perceived an analogy, and that this is all that is necessary to validate the analogy, is not sufficient. Even I am but mad north-north-west: when the wind is southerly I know a hawk from a handsaw.

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

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

Allen

General 19 Mar 2009 05:30 pm

Should Embryonic Stem Cells be Used for Medical Research?

On Monday 9 March 2009 President Obama signed an executive order reversing the Bush administration’s ban on the use of Federal funding for embryonic stem cells for medical research (and presumably for any medical treatments that might eventually be developed as the result of that research). This policy change has raised a storm of controversy among right-to-life- advocates, and also among “intelligent design” supporters. This controversy has centered on the ethics of science, and whether scientists should be allowed to pursue their research wherever it leads.

Currently, most embryonic stem cells are derived from human egg cells that have been fertilized in vitro (that is, outside of the body of the egg-donor mother) as part of the process of in vitro fertilization (IVF) whereby childless couples can conceive of a baby using their own genetic material.

IVF clinics generally fertilize multiple donor eggs and then let them
divide by mitosis
until the blastula stage is reached. During this process the inner cell mass is formed inside the blastula, from which embryonic stem cells are derived. The point to this process is not to produce the embryonic stem cells in the inner cell mass, but rather to produce viable blastulas, which can then be implanted in the uterus of the egg donor (or, in rare cases, a surrogate).

The way this process is carried out necessarily produces multiple unused blastula-stage embryos for every one that is implanted. These unused blastula-stage embryos are usually frozen in liquid nitrogen, in case the egg donor requires a repeat implantation.

Currently, there are almost half a million such blastula-stage embryos frozen in liquid nitrogen in IVF clinics in the United States, which leads to the first ethical question:

What becomes of the unused frozen embryos, and who decides?

Here is what generally happens:

Any embryos that you do not use in your first IVF attempt can be frozen for later use. This will save you money if you undergo IVF a second or third time. If you do not want your leftover embryos, you may donate them to another infertile couple, or you and your partner can ask the clinic to destroy the embryos. Both you and your partner must agree before the clinic will destroy or donate your embryos. [source]

So, should the “parents” (i.e. the egg and sperm donors) have the right to decide that their unused blastula-stage embryos be destroyed? Despite some political efforts to deny them this right, there is no legal jurisdiction in the U.S. in which this right has been abrogated (yet).

One way to solve this particular ethic dilemma is to “adopt” the frozen embryos by having them implanted in an “adoptive” mother. There is an organization that advocates this, Nightlight Christian Adoptions, and has arranged for some of these frozen embryos (which the organization calls “snowflakes”) to be “adopted” by implantation in “adoptive” mothers who are medically infertile (and married).

According to data at that website, the current number of successful “snowflake adoptions” is approximately 202 since the program was started in 1997. That works out to around 17 per year, or 0.0034% of the current half-million “snowflake backlog”. At that rate, all of the frozen embryos currently in cryogenic suspended animation will be “adopted” by the year 31421.

However, this grossly underestimates how long this backlog will persist, as it assumes that no new “snowflakes” are generated by new IVF procedures. Currently, the rate of production of new frozen blastula-stage embryos at IVF clinics in the US is approximately 18,000 per year. The current rate of “snowflake adoption” is approximately 20 per year, so unless IVF is permanently stopped, it is mathematically impossible for the current “snowflake backlog” to eventually be “adopted”.

One way to avoid the use of embryonic stem cells taken from frozen blastula-stage human embryos is to use adult stem cells instead. There are many different tissues in adult humans that qualify as pluripotent stem cells (that is, cells that can continue to divide by mitosis). Recent research has made it possible to “regress” adult stem cells almost to the embryonic stem cell stage, which raises the possibility of using adult stem cells instead of embryonic stem cells.

Personally, I strongly hope that adult stem cells can be used for all of the scientific and technical uses that most scientists originally thought only embryonic stem cells could be used for. However, this will then lead to two new, unforseen ethical dilemmas:

What will be done with the “snowflakes” that are currently frozen at IVF clinics, if they are not used for stem cell research and medical treatment?

and

What will be done with the adult stem cells that have been regressed to the embryonic stem cell stage, since these would then qualify genetically and developmentally as “snowflakes” themselves?

Clearly, one irony of the development of adult stem cell regression will be that the “snowflakes” now frozen in liquid nitrogen in all of those IVF labs will now almost certainly be disposed of (I suppose they defrost and incinerate them), rather than contributing to the advance of medical technology and human welfare.

The other irony, of course, is that by regressing adult stem cells to the embryonic stem cell stage, there would be many more “snowflakes”, rather than fewer, thereby necessitating the destruction of many more “potential human beings” than is currently the case.

There are two other solutions, both of which avoid the ethical dilemmas outlined above. One alternative would be:

To consider that neither embryonic stem cells nor adult stem cells are “human beings” until they are implanted into a mother and are born as human babies.

This, of course, would require defining “human life” as beginning at birth, rather than “conception” (regardless of where that “conception” took place).

Another alternative would be:

To consider that all stem cells are “human beings”, which would require that all stem cell research and treatment and all forms of in vitro fertilization be declared unethical, and presumably outlawed.

But this would also require that we outlaw all developmental research, because somewhere along the line some researcher somewhere might find out how to regress any human cell to the embryonic stem cell stage, and then simply scratching your head or drinking a cup of too-hot coffee would be equivalent to murder.

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

Allen

General 28 Jul 2008 05:31 pm

Phillip Johnson & “Theistic Realism”


AUTHOR: Allen MacNeill

SOURCE: Original essay (repost from The Evolution List)

COMMENTARY: That’s up to you…

Phillip Johnson, one of the founders of the intelligent design movement, has proposed an alternative form of reasoning to that used by modern scientists. He refers to his form of reasoning as “theistic realism”, while the alternative could be called “empirical naturalism”. In this blog post, I intend to contrast these two forms of reasoning, to determine what assumptions one must hold to apply them, and what consequences flow from adopting one or the other position, which I freely admit at the outset are essentially metaphysical (i.e. not scientific) positions.

According to Charles Darwin, Ernst Mayr (and most other evolutionary biologists), evolution has two stages:
• the origin of variations via various mechanisms
• the origin of adaptations via natural selection

Johnson’s critique of evolution centers on the origin and patterns of variation, since he has repeatedly granted in various venues that natural selection occurs. However, according to Johnson, “God” (i.e. the supernatural entity/force behind “theistic realism”) causes and/or guides the generation of variations, leaving natural selection as a mere “stabilizing force” that only maintains adaptations by weeding out unfit individuals. In this sense, Johnson’s version of “natural selection” is virtually indistinguishable from that proposed in 1835-37 by Edward Blyth.

There are two fundamental problems with Johnson’s position, one theological and one metaphysical:

• First, the idea that stabilizing selection maintains God-created variations is essentially a form of “statistical norming”, and therefore violates the Judeo-Christian (and presumably, “theistically realistic”) principle of “sanctity of the individual”. If “not a sparrow falls, but that [God is] mindful of it”, then God doesn’t (indeed, cannot) treat individuals (including, presumably, individual humans) as instrumental entities (i.e. as means, rather than as ends) by weeding them out if they depart too much from the statistical norm of His created types. But, if God does pay attention and therefore intervenes on behalf of any and all individuals, then stabilizing selection doesn’t really exist, and we are back to a theory of “theistic evolution” in which God directly intervenes in nature, controlling and guiding (i.e. determining) absolutely everything that happens at all times and in all places.

• Second, if Johnson grants that God directly intervenes only in the generation of variations (and lets stabilizing selection maintain the particular variations He specifies), there are still two alternatives:

- That God creates a multiplicity of variations, and then lets natural selection operate to choose which ones will become adaptations; or

- That God determines which variations will be adaptive at the instant of their creation, thereby rendering natural selection (and all naturalistic mechanisms of variation) superfluous.

In the first case, God not only commits the sin of “statistical norming” (as described above), the process by which He does so would result in a pattern of evolutionary change that would be virtually indistinguishable from purely naturalistic evolution by natural selection, which does not require God to intervene at all. He would, in other words, render Himself and His actions completely pointless and invisible.

But in the second case, the apparent stabilizing selection described earlier is illusory, since all created individuals would be ipso facto adaptive. Indeed, unless God deliberately intends to create maladaptive individuals that depart significantly from the adaptive norm (and which therefore would be eliminated by selection), there should be virtually no maladaptive individuals at all, which should be easily verifiable by empirical analysis.

Either Johnson must grant that stabilizing selection does, in fact, operate (and God is therefore not mindful of individuals, but only of types), or he must grant that it does not. In the second case, natural selection doesn’t really happen at all, at any level, and God must therefore intervene directly in the survival and reproduction of every living organism that has ever existed, exists, or ever will exist. Furthermore, God does this despite the fact that only one type of organism, namely humans, has any choice about its behavior, about its living or dying (as far as we can tell).

To sum up, either:

• God (or the “Intelligent Designer”) intervenes directly in evolution via stabilizing selection, thereby destroying uncountable trillions of His creations (all of them innocent except humans, and even some of them, too) in order to “stabilize” His specified adaptations, or

• God (or the “Intelligent Designer”) doesn’t intervene via stabilizing selection, in which case He’s either irrelevant (i.e. natural selection “just happens”) or He completely determines absolutely every event that occurs throughout all time and space, in which case “free will” (and therefore sin) is an illusion.

Furthermore, since Johnson grants that natural selection really does occur, but only as stabilizing selection, this limits God’s intervention in the evolutionary process to the instant of the creation of variations. Under such conditions, the circumstances following this instant are empirically indistinguishable from pure naturalistic processes, regardless of whether God “specifies” such variations. Either that, or such variation is essentially random (and therefore “Godless” and “unspecified”).

But this position puts Johnson inescapably in the position of arguing once again for a “God of the gaps” position, since the only intervention God is capable of under such conditions is into the generation of variations; what happens afterwards is essentially “Godless”. This is a “God of the gaps” position because there are only two alternative scenarios:

• A mechanism that produces variations that does not rely upon supernatural intervention will eventually be discovered and applied to the entire fossil and genetic record, the “gap” will be closed, and God (like the Baker) will “softly and silently vanish away”; or

• No matter when one inquires, a mechanism that unambiguously does not rely upon supernatural intervention will not yet have been (and indeed, cannot ever be) discovered.

It would seem like the second situation would validate Johnson’s position. However, the second situation involves a fundamental (i.e. metaphysical) problem: the only absolutely validating outcome for the second alternative is that every possible mechanical (i.e. “Godless”) explanation for the origin of variations must have been tested and falsified. This is a metaphysical impossibility, as the empirical method relies on induction, and no amount of positive evidence for Johnson’s hypothesis (i.e. negative evidence for a “Godless” origin of variations) is enough to absolutely validate it (unless Johnson wishes to declare himself a logical positivist, which seems highly unlikely).

Given the foregoing, it appears that Johnson’s assertion that God guides the origin of variations directly violates Popper’s falsifiability criterion (just as Johnson claims evolutionary theory does). This is because, no matter how fine a level of discrimination one specifies for ruling out supernatural intervention in the origin of variations, Johnson can claim that God’s intervention lies somewhere “deeper” (even if we someday get down to the level of sub-subatomic particles).

But, at some arbitrarily fine level of discrimination, either God’s intervention will “jump out” of the statistical analysis (i.e. it will violate accepted principles of statistical reliability) or it won’t. If it doesn’t, the hypothesis of God’s direct intervention in the origin of variations will have once again become unnecessary, and by the standard of parsimony (i.e. “Occam’s razor”), if a causal factor is unnecessary, it isn’t included in a scientific (i.e. empirically grounded) explanation of a phenomenon.

When one examines Johnson’s metaphysical positions on these subjects, it is clear that he doesn’t give a damn about empirical validation or falsifiability or statistical reliability or anything else that could conceivably be called “scientific”. For example, in Defeating Darwinism by Opening Minds [1], Johnson states quite unequivocally:

“Truth (with a capital T) is truth as God knows it. When God is no longer in the picture there can be no Truth, only conflicting human opinions. (There also can be no sin, and consciousness of sin is that built-in moral compass [pro-Darwinian philosophers] reject…as illusory.)” [Defeating Darwinism by Opening Minds, page 89]

In my opinion, no more succinct a statement of anti-scientific thinking could be imagined. Johnson asserts that the only two alternatives are
(1) God-given Truth and
(2) conflicting human opinions.
Where, in either of these, is empirical verification? Is “God-given Truth” amenable to empirical verification? If Johnson thinks so, he flies in the face of centuries of both scientific and theological metaphysics, which has consistently concluded exactly the opposite. But what about the alternative: is Johnson asserting that all scientific principles, such as the law of gravity, are “human opinions”? This was the position taken by the author of the “Sokol Hoax”, which of course was shown to be both a hoax and an indirect validation of the assumption that physical laws are not subject to human opinions. Ergo, if Phillip Johnson were of the opinion that the law of gravity does not apply to him, could he thereby escape its operation? Don’t be ridiculous…

Johnson argues that we should, as scientists, conflate two totally incommensurate forms of “knowing”:

Deontological Absolutism - a universe in which God’s direct intervention in events occurring in the real world is self-evident and does not require empirical verification (in fact, to attempt such verification would qualify as blasphemy), or

Scientific Empiricism - a universe in which the assumption that God intervenes in any event that occurs in the phenomenal/physical universe is unnecessary, and therefore irrelevant to such an explanation.

That’s what all this really comes down to: Johnson’s “theistic realism” is semantically reducible to “its True because I say so, and I say so because I believe that God says so, too”, since no amount of empirical evidence can either validate (or invalidate) his position. The only “proof” he provides (or requires) for his position is his assertion of it. Interesting, perhaps, as an exercise in theological metaphysics (not to mention hubris), but not, by any stretch of the imagination, science.

REFERENCES CITED:

[1] Johnson, Phillip (1997) Defeating Darwinism by Opening Minds, InterVarsity Press, Downers Grove, IL, ISBN #0830813624, 137 pages.

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

Allen

General 02 Jul 2008 07:47 pm

Day One of the Evolution Revolution

AUTHOR: Allen MacNeill

SOURCE: The Evolution List (repost)

COMMENTARY: That’s up to you…

I have mentioned several times in other posts that 2008 is the bicentennial of the birth of Charles Darwin and the sesquicentennial of the publication of the Origin of Species. Hundreds of scientific and cultural organizations are gearing up to celebrate Darwin’s birthday on February 12th, proclaiming it the kickoff for the “Darwin bicentennial year”.

However, in a very real sense, today is the first day of that centennial celebration. On the first of July 1858 two papers and two letters were read to the members of the Linnean Society in London. One of the papers, entitled “On the Tendency for Varieties to Depart Indefinitely from the Original Type”, was written by Alfred Russell Wallace. The other paper and the two letters were written by Charles Darwin, and outlined his theory of evolution by natural selection.

The paper by Wallace had been sent to Darwin, with a request by Wallace that if it were of sufficient merit, would he please forward to the society for publication? Darwin was stunned; he had been working on the very same idea for almost twenty years. Here is what he wrote on 18 June 1858 to his friend, the geologist Charles Lyell, following his receipt of Wallace’s paper:

My dear Lyell

Some year or so ago, you recommended me to read a paper by Wallace in the Annals [a natural history journal], which had interested you & as I was writing to him, I knew this would please him much, so I told him. He has to day sent me the enclosed [manuscript] & asked me to forward it to you. It seems to me well worth reading. Your words have come true with a vengeance that I shd be forestalled. You said this when I explained to you here very briefly my views of “Natural Selection” depending on the Struggle for existence.—I never saw a more striking coincidence. if Wallace had my M.S. sketch written out in 1842 he could not have made a better short abstract! Even his terms now stand as Heads of my Chapters.

Please return me the M.S. which he does not say he wishes me to publish; but I shall of course at once write & offer to send to any Journal. So all my originality, whatever it may amount to, will be smashed. Though my Book, if it will ever have any value, will not be deteriorated; as all the labour consists in the application of the theory.

I hope you will approve of Wallace’s sketch, that I may tell him what you say.

My dear Lyell
Yours most truly

C. Darwin

Knowing how long Darwin had labored on his theory, Lyell and botanist Joseph Hooker prevailed on Darwin to allow them to read his unpublished essay on natural selection (written in 1844) and two letters on the same subject from Darwin to Hooker and to the American botanist, Asa Gray, along with Wallace’s paper at the July meeting of the Linnean Society. Neither Darwin nor Wallace attended the meeting (Darwin was at his home at Down, in Kent, mourning the death of his son, Charles, who had died three days earlier; Wallace was still in the Maylay archipelago), and the joint reading raised hardly a ripple of comment.

Despite their lack of notoriety at first, these papers and letters were the first public presentation of the theory that would fundamentally and radically change the way we view ourselves and the natural world around us.

Here are some links to websites with much more information about this sesquicentennial event:

Happy 150th Birthday Natural Selection!

On the Tendency of Species to form Varieties

How Darwin won the evolution race

Darwin, Wallace and The Linnean Society of London

150th Anniversary of the Darwin-Wallace Papers

The Darwin-Wallace Letters of 1858

Fire the starting gun! The Darwin year begins…NOW!

Previous anniversary celebrations

July 1, 1858: Darwin and Wallace Shift the Paradigm

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

Allen

General 15 Jun 2007 02:25 am

What is the “Engine” of Evolution”

engine.jpg

AUTHOR: Allen MacNeill

SOURCE: The Evolution List (repost)

COMMENTARY: That’s up to you…

Ever since Darwin, the primary “engine” of evolution has been considered to be natural selection. However, if one takes a closer look at this, it is clear that natural selection is not an “engine,” it is an outcome. If evolution is defined as change in the characteristics of the members of a population over time and natural selection is defined as unequal non-random survival and reproduction (or, more parsimoniously, differential reproductive success), then the underlying cause of the changes that are differentially preserved over time is the real “engine” of evolution by natural selection.

And what might this “engine” of change be? Exactly what Darwin said it was in the Origin of Species: the “laws of variation” of which naturalists of his time were almost “completely ignorant.” That is, given that some variations are heritable and that they can be passed from parents to offspring in the process of reproduction, then it is the processes that cause such variations that are the real “engine(s)” of evolution, including evolution by natural selection.

Darwin was on the right track when later on he sought out the specifics of the “engines of variation” in Variation of Animals and Plants Under Domestication, published in 1868. Darwin suggested that the rate of variation changed over time, in response to specific changes in the environment. For example, he pointed out that the variation between domesticated animals and plants was considerably greater than that found in the wild. This suggested to him that something about domestication – increased food, improved nutrition, lack of predators, etc. – caused an increase in the production of variations that were then exploited by animal and plant breeders.

However, it is now generally accepted that the only real difference between domesticated and wild animals and plants, in terms of variation, is that the conditions of domestication allow more variants to survive and reproduce, rather than causing more of them to be produced in the first place. I do not know enough genetics to say whether or not this is the case, but it seems to me at least that Darwin’s idea is worth empirical investigation. Here are the relevant questions (which may or may not already have answers):

• Is the rate of generation of genetic and phenotypic variation a constant?

If the answer to this question is “yes,” then all we need to investigate is the actual genetic and developmental mechanisms by which such variations are generated. However, if the answer is “no,” then the rate of generation of genetic and phenotypic variations is variable, which immediately suggests more questions:

• Is the increased rate of generation of variations correlated with any identifiable factor in either the genetics/development or the environment of organisms in which such variable rates of variation are observed?

If the answer to this question is “no,” then we may safely assume that the underlying “engine(s)” of variation is/are entirely random, insofar as we can observe it changing randomly over time. However, if the answer is “yes,” then there are more questions:

• Via what mechanism(s) is the increased rate of variation generated, and are the “triggers” for such increased variation endogenous, exogenous, or some combination of the two?

Clearly, the “engine(s)” of variation are prodigious, as it/they have been able over time to modify something as simple as a mycoplasm into an oak tree or a blue whale. Some supporters of “intelligent design” (ID) would dispute this statement, of course, claiming (without any empirical evidence) that “you can’t get here from there.” However, we clearly have gotten here from there; the real question is “how?” There are logically at least two possibilities:

• The process(es) by which the “engine(s) of variation” have produced the necessary variation have operated endogenously by means of a prodigious (and undirected) “random variation generator,” the products of which have been sorted over time by natural selection (i.e. the Darwinian hypothesis), or

• The process(es) by which the “engine(s) of variation” have produced the necessary variation have operated endogenously by means of a less prodigious “non-random variation generator,” the products of which have been sorted over time by natural selection (i.e. the ID hypothesis).

Noticing that the only difference between these two possibilities is the amount of variation and its source immediately suggests a way of testing the two hypotheses: do the currently identified mechanisms of genetic and phenotypic variation produce enough variation to get from there to here, or not? If the answer is “yes,” then the ID hypothesis is unnecessary, and therefore irrelevent to science.

So, the next obvious question is, what are the currently identified mechanisms of genetic and phenotypic variation, and do they provide enough variation to get here from there? The answer to this question will be posted soon -watch this space.

And as always, comments, criticisms, and suggestions are warmly welcomed!

Allen

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