Evolutionary Psychology: The Science of Human Nature

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 May. 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

What is "Darwinism" and am I a "Darwinist"?

I don’t use the term “Darwinism” at all, any more than I would use the term “Newtonism” when referring to classical physical mechanics, “Einsteinism” to refer to relativity theory, “Bohr/Feinman/Heisenberg/Schroedingerism” to refer to quantum mechanics, or “Mendeleevianism” to refer to chemistry. What I and my colleagues (and friends) do is probably best described as “evolutionary biology”, and includes (at a bare minimum) the following:

1) the formulation and testing of a set of interconnected theories explaining the origin of biological diversity, consisting of descent with modification from common ancestors over deep geological time, describable via cladistic analysis, and supported by inference from multiple sources of empirical evidence, including comparative anatomy, biogeography, developmental biology, genomics, historical geology, and paleontology; and

2) the formulation and testing of a separate but related set of interconnected theories explaining the origin and modification of the phenotypic characteristics of living organisms, consisting (at a bare minumum) of the mechanisms of natural selection, sexual selection, genetic drift, and neutral molecular evolution in deep geological time, grounded (at least in part) in theoretical mathematical models of population genetics, depending on multiple sources of heritable phenotypic variation, and supported by inference from multiple sources of empirical evidence, including field and laboratory research in the fields of biochemistry, cell biology, comparative physiology, developmental biology, ecology, ethology, genetics, neurobiology, and physiological ecology.

Note that these two definitions of the principle domains of evolutionary biology correspond roughly to what are sometimes referred to as “macroevolutionary theory” and “microevolutionary theory” (in that order) and do not explicitly mention:

• theories of the origin of life from non-living materials, which are properly the purview of astrophysics, chemistry, and geology, not biology;

• the concept of “adaptation”, which has had a checkered past in evolutionary biology and is facing increasing challenges within the field; and

• teleology, which is almost never mentioned, except for those evolutionary biologists who have thought about it (which, in my experience, are relatively few), who generally assume that resort to teleological explanations in evolutionary biology is unnecessary. Not wrong, just unnecessary (not to mention unproductive as an empirical research hypothesis).

As philosophical concepts, both adaptation and teleology have a very long history, stretching back at least to Plato and Aristotle. However, recent developments in evolutionary theory, including (but not limited to) theories of epigenetics, exaptation, genetic drift/draft, neutral and nearly neutral molecular “drift” in deep evolutionary time, and punctuated equilibrium, have rendered the concept of “adaptation” as an increasingly marginal diversion rather than a central topic in evolutionary biology.

And teleology, rather than being considered “wrong” (when it is considered at all, which is seldom) is now increasingly being incorporated into new theories of “evolved agency”, especially in evolutionary psychology (my own field). I am currently working on a treatise on this latter subject, which I hope to finish before departing this veil of tears and laughter for that undiscovered country from whose bourn no traveller returns.

Memento mori: The Metaphysics of The Game

I just lost the game. And so have you, especially if you know what I'm talking about.

Some background: my eldest son, Conall, attended a highland dance camp this past summer. While he was there, he learned about The Game. Being obsessed with games in general and mind games in particular (like his dad), he came home and told us all about it, and has since reveled in telling us every time he loses the game. Since learning about The Game, I have myself announced the same to several of my classes at Cornell, each time to a chorus of groans.

So, how does The Game work?

The Game has only three rules:

1) Everyone is always playing The Game.

2) Whenever you think of The Game, you lose.

3) Having lost The Game, you must announce this to at least one other person (usually by saying or writing "I just lost The Game").

Some active players of The Game also assert that there are two corollaries:

4) You can lose The Game multiple times.

5) You can only lose The Game once every half hour.

That is, The Game "resets" after half an hour, so that having forgotten that you are playing, you can lose again and again and again...

Having lost The Game many, many times since Conall told me the rules, it has occurred to me that there is a metaphysical dimension to The Game. Thinking about The Game is essentially the same thing as thinking about one's own death. That is, The Game is a kind of memento mori. Most of us go through most of our lives without often thinking about the incontrovertible fact that all of us will, at some point in the indefinite future, cease to exist. We will all, in other words, "lose The Game".

There have been several times in my life when I have become bemused by the thought of my own mortality. The first time it happened I was four years old. We were living in an old farmhouse on Scott Road, east of Homer, New York, and I was walking up the stairs to my bedroom. Between one step and the next, it occurred to me that I would someday die - that I would cease to exist. This realization was very shocking to me, and came back into my mind steadily for some time.

But then, I forgot about it...for a while. Since then, I have gotten caught in the same "becoming aware of mortality loop" several times, and each time it has had the same quality as losing The Game. That is, it comes with a sense of "doubled consciousness", in which I have become conscious of my own stream of consciousness, and its eventual termination.

Many theologians (and some evolutionary biologists) have speculated that the origin of religion is grounded in the realization of personal mortality. From an evolutionary standpoint, the argument is as follows:

1) Individuals who avoid situations in which their lives are threatened survive (and can therefore reproduce) more often than individuals who do not avoid such situations.

2) Individuals who are aware of their own mortality are more likely to avoid situations in which their lives are potentially threatened.

3) Ergo, the cognitive operation in which one becomes conscious of one's mortality has adaptive value; that is, it can increase in frequency among the individuals that make up a population as the result of natural selection.

Some evolutionary psychologists (myself among them) have argued that the capacity for such cognitive operations is the basis for our evolved psychology, and that there is a positive feedback relationship between ideas like "mortality" (and The Game) and the underlying neurological wiring that facilitates the acquisition and transmission of such ideas. This idea, known as "gene-meme coevolution", was first and most rigorously explored by Charles Lumsden and Edward O. Wilson in their 1983 book, Genes, Mind, and Culture: The Coevolutionary Process. The underlying ideas in their work were summarized in non-technical language in Promethean Fire: Reflections on the Origin of Mind.

Having pondered both The Game and mortality, it seems quite plausible to me that our minds are indeed adapted to the kind of mental operation that results in both "losing The Game" and recalling our personal mortality. And so, I expect to go on losing The Game until I lose The Game...and now, having read this, so will you.

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

--Allen

"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

Chance and Necessity

AUTHOR: Allen MacNeill

SOURCE: Original essay

COMMENTARY: That's up to you...

One of the main disagreements between evolutionary biologists and "intelligent design" supporters is the role of "chance" (also called "randomness") in the origin of biological objects and processes (especially adaptations). In many cases, it seems that this disagreement is exacerbated by a disagreement about what the antonym of "chance" might be. In my experience, many people on both sides of the EB/ID disagreement think that the opposite of a "chance" event is an event that was "caused". However, this ignores the fact that many scientific explanations now include "chance" or "random" processes in causal explanations of natural objects and processes.

In this context, therefore, I propose that the antonym for "chance" is "necessity", as was first pointed out by Democritus of Abdera in the 4th century BC, whose two famous aphorisms were:

"All things are the fruit of chance and necessity"

and

"Nothing exists except atoms and the void".

The phrase "chance and necessity" is often used as a descriptive term in modern science. It means essentially "all natural/physical causes", or what one might consider to be the "Newtonian" world view. The reason that evolutionary biologists consider that Darwin founded the science of biology is that he proposed a theory of descent with modification and the origin of adaptations that was based entirely on "chance and necessity", thereby "unifying" biology with the other natural sciences.

However, it is clear that there is a myriad of objects and processes in the universe that are not entirely the "fruit of chance and necessity", just as there are clearly "things" that are neither "atoms" or "void". In purely physical terms, we now recognize at least three "things" in nature: mass, energy, and information. Only the first of these three qualifies under Democritus second aphorism, as neither energy nor information qualify as "things". Energy, of course, is interconvertable with matter according to Einstein's famous energy/matter equation. However, in the form of "pure" energy (such as electromagnetic radiation), energy is not detectable unless and until it interacts with matter (this is why outer space appears black, even though it is filled with light).

The "detectability" problem of energy is even more difficult in the case of information. It seems clear that all forms of information involve some sort of "translation", in which matter/energy relationships are "translated" into information, which can be stored and transmitted in forms that are not entirely reducible to the original matter/energy forms which they represent. As Korbzybski famously said, "the map is not the territory"; the representation (in the form of information) is not the "thing" represented".

No one, including hard-core "naturalists", suggests that information doesn't exist. The problem (and this is where EB and ID run into serious difficulty), is how (and perhaps by whom) information can become "translated" in the first place. It is not even completely clear that simple "natural" processes (such as the photoelectric effect) do not include an exchange of "information" as well as an exchange of energy (in the form of a photon, for example). In quantum electrodynamics, does the exchange of a photon (or, even worse, a virtual photon) constitute an exchange of "information" between the interacting particles?

In classical physics, there is no "arrow of time". Newtonian mechanics can be run forward or backward in time, with no contradictions (and no way to tell which way the process is happening). However, in those branches of modern physics in which random processes play a part (statistical mechanics, thermodynamics, and quantum mechanics), randomness is necessarily tied to "time's arrow". The same is apparently the case with information, at least in its Shannon form.

Ergo, it seems to me that the problem of information is one that is necessarily tied with the concept of "chance". Indeed, I have come to think that information is a manifestation of one of the operations of "chance" in nature; without information, chance overwhelms everything and the universe disintegrates into permanent incoherence.

This is clearly the case in biology. The "fixing" of information in the physical form of the genetic material is the only thing that makes biology possible. Without such "physicallization" of information (in the form of DNA, RNA, proteins, etc.) biological systems would be impossible, as they would disintegrate into incoherence.

Ergo, the transition from purely physical (i.e. mechanical/Newtonian) processes that do not include the translation and transfer of "translated" information to biological processes that necessarily involve the translation and transfer of "translated" information is the central problem of both biology and the physical sciences. As I have written before, I am not sanguine about our ability to answer this problem using historical information, as the transition occurred at a time (and perhaps in a place) which has left no traces from which we can infer its dynamics.

This leaves us with theoretical models, which are of course based on metaphysical assumptions about reality. I believe it would be fair to say that IDers assume that information can exist without a physical referrent (i.e. something that "carries" or "transmits" the information), whereas EBers (along with most other natural scientists) assume that information must have a physical referrent (i.e. it cannot exist in purely "disembodied" form).

Furthermore, it seems clear from previous discussions in this forum that IDers assume that information can be "foresighted"; that is, it can somehow anticipate future outcomes, not by "induction" from the past but by some kind of "deduction" from the future. EBers (again, like most other natural scientists) assume that "time's arrow" cannot point backward, and that the future is therefore relentlessly driven by the past.

It seems to me that the foregoing lays out the problems which which any scientific theory of "origins" must come to grips:

• whether information can exist in purely "disembodied" form in nature, without a physical referrent

• whether the origin of the "translation" of information into physical form (i.e. the origin of the genetic translation machinery of living organisms) cannot take place without an input of "disembodied" information

• whether any form of information transfer can be genuinely "foresighted" (i.e. can be modified by events that have not yet happened, rather than simply predicting future events based on events that have happened in the past).

Evolutionary biologists (and the vast majority of all natural scientists) begin with a metaphysical world view in which their starting assumptions answer these three questions with NO. By contrast, most of the ID supporters with whom I have had such discussions begin with a metaphysical world view in which their starting assumptions are exactly the opposite: they answer these three questions with YES.

Personally, I believe that the metaphysical world view of most scientists is easier to work with, as it requires fewer "YES" answers to these questions (i.e. it requires fewer unverifiable assumptions about things that must exist for the universe to work). However, I freely admit that this belief is on a par with my acceptance of "Occam's razor" as a basic principle of scientific explanation. That is, "Occam's razor" clearly isn't "true", it's just useful as a rule of thumb in doing science.

So, where does this leave us? I think it explains why most scientists are uncomfortable with the word "design" being applied to biological objects and processes. As I have pointed out, Ernst Mayr argued for the legitimacy of the concept of design in biology, when what was meant by that term was the idea that organisms are "designed" by the information encoded in their genomes, interacting with the information obtained from interactions with their environments. This is because this view of biological "design" conforms to the three answers to the three questions listed above as answered by most scientists.

However, Mayr (and virtually all other evolutionary biologists) was uncomfortable with the idea that the process by which genomes and environments came into being was also "designed" - that is, that there was some foresighted process in which intention played a part in the bringing into existence of the physically embodied objects and processes in biology. Again, this is because this view of biological "design" does not conform to the three answers to the three questions listed above as answered by most scientists.

Where do we go from here?

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

--Allen

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.

Teleological and Teleonomic: A New(er) Analysis

AUTHOR: Ernst Mayr

SOURCE: Boston Studies in the Philosophy of Science, Volume XIV, pages 91 -117

COMMENTARY: Allen MacNeill

On April 17, 2006 04:35 PM David B. Benson wrote in the Panda's Thumb (scroll way down):

[Can you] explain why you state that ant colonies, cities, and other emergent organizations have purpose? In particular, what is wrong with mere teleomentalism, that an ascription of purposeful behavior is only metaphor?

Ernst Mayr [1] distinquished between two different kinds of natural processes that appear to be “goal directed”:

Teleomatic processes: Processes that simply follow natural laws, i.e. lead to a result consequential to concomitant physical forces, and the reaching of their end state is not controlled by a built-in program. The law of gravity and the second law of thermodynamics are among the natural laws which most frequently govern teleomatic processes. Examples include the cooling to ambient temperature of a red hot bar of iron and the falling of a rock to the ground.

Teleonomic processes: Processes that owe their goal-directedness to the operation of a program. The term teleonomic implies goal-direction. This, in turn, implies a dynamic process rather than a static condition, as represented by a system. Examples include the development of an adult organism from a fertilized zygote and the building of a dam by beavers.

Mayr argues very strongly that the common use of teleological language by biologists is legitimate because it recognizes the goal-directedness of biological processes. He also stresses that, although many biological processes (such as ontogeny) are clearly goal-directed, they owe their goal-directedness to the operation of programs, such as the genetic program encoded in the DNA. He concludes that although such programs themselves are goal-directed (i.e. purposeful), the process by which such programs have come into being – evolution by natural selection – is NOT itself goal directed.

[ I would state this slightly differently from Mayr: that there is no observable evidence that the evolutionary processes by which such programs come into being are goal-directed (i.e. “designed” or “purposeful”). Therefore, although such purposes may exist, they are invisible to us on principle and therefore irrelevent to scientific explanations of natural phenomena.]

Mayr concludes:

• The use of so-called teleological language by biologists is legitimate; it neither implies a rejection of physico-chemical explanation nor does it imply non-causal explanation

• At the same time, it is illegitimate to describe evolutionary processes or trends as goal-directed (teleological). Selection [reifies] past phenomena (mutation, recombination, etc.), but does NOT plan for the future, at least not in any specific way [as far as we can tell]

• Processes (behavior) whose goal-directedness is controlled by a program may be referred to as teleonomic

• Processes which reach an end state caused by natural laws (e.g. gravity, second law of thermodynamics) but not by a program may be designated as teleomatic

• Programs [of the type described above] are in part or entirely the product of natural selection

• Teleonomic (i.e. programmed) behavior occurs only in organisms (and man-made machines) and constitutes a clear-cut difference between the levels of complexity in living and in inanimate nature [i.e. they are “emergent properties” of living systems, not present in the non-living materials of which living organisms or their artifacts are composed]

• Teleonomic explanations are strictly causal and mechanistic. They give no comfort to adherents of vitalistic concepts [including supporters of “intelligent design,” if such supporters believe that the kinds of programs desctibed above come into existence as the result of a purposeful process]

• The heuristic value of the teleological Fragestellung makes it a powerful tool in biological analysis, from the study of the structural configuration of macromolecules up to the study of cooperative behavior in social systems.

COMMENTARY:

I agree with Mayr on virtually every point. In other of his publications, Mayr argues strongly for the idea that biological systems exhibit “emergent properties,” and that this is one of the primary differences between biology and the other natural sciences, such as physics. At the same time (and contra some supporters of “emergent properties,” such as Andrew North Whitehead and Teilhard de Chardin), Mayr argues very strongly for the naturalist position that such properties are well within both the darwinian paradigm and the tradition of naturalistic explanation that underlies the natural sciences.

Given the foregoing, I therefore believe that the kind of teleonomy exhibited by ants and ant colonies is indeed a natural property of such biological systems, and not just a “teleomentalism” (i.e. a semantic distinction rooted in human language and cognition, having no actual reality in nature). Furthermore, it seems to me that the kinds of advances that we have seen since Mayr wrote his paper – developments in artificial intelligence and the programming of cybernetic “expert systems”, advances in genetics, and especially a much deeper understanding of the processes of evolutionary development – lend support to Mayr’s analysis, and that using Mayr’s theoretical framework can not only assist people working in the aforementioned fields, it can also lead to some clarity in understanding the origin and evolution of purpose in nature.

This analysis leaves us with the following problem: Is the term "teleology" an umbrella term that subsumes both teleomatic and teleonomic processes, and if so, what term is most appropriate for the kinds of unambiguously goal-directed behavior exhibited by humans (and our artifacts, such as heat-seeking missiles)? My preference is to reserve the term "teleology" for the latter (i.e. clearly goal-seeking processes initiated and controlled by rational entities, such as ourselves), and apply the terms teleonomy and teleomatic the way Mayr suggests in his article.

I believe that these distinctions clearly and unambiguously distinguish between natural processes that appear to be (or even are) goal-directed, such as ontology, and processes that are not, such as natural selection and other evolutionary mechanisms.

And yes, before an ID supporter points out the obvious, the foregoing analysis doesn't eliminate the problem of evolution versus ID, since ID theorists can still argue that God (remember, I asserted a while back that I will use the proper/role name "God" instead of "the intelligent designer"...it requires fewer keystrokes and is more honest IMHO) both "designed" and "guided" the processes by which Mayr's "programs" bring about teleonomic goal-seeking behavior.

But that discussion will have to wait for another post...

REFERENCES CITED:

[1] (Mayr, E. (1974) “Teleological and Teleonomic: A New Analysis.” Boston Studies in the Philosophy of Science, Volume XIV, pages 91 -117),

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

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.

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AUTHOR'S' BIOGRAPHICAL & CONTACT INFORMATION:

Robert Roy Britt is the Managing Editor for LiveScience.com

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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

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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

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