Posted tagged ‘Evolutionary mechanisms’

Why is there substantial overlap between design results and evolutionary results?

December 2, 2008

There are a number of reasons why ID exists, from an unreasonable desire to hold onto religious myths, to the amazing lack of any sort of scientific rigor in the vast majority of either their criticisms or in their “models” (this statement is not to be confused with their frequent unreasonable demands that we supply rigor where unknowns remain, while they hold themselves to be exempt from any scientific rigor).  This is not the place to delve into the many evolutionary faults in the brain which keep pseudosciences like ID going, however. 

One issue in the constant struggle against ID and other forms of creationism is that the inference to design in life is both an anthrocentric mistake (in that “purpose” is inferred where only evolutionary function can be demonstrated), and sometimes an honest mistaking of exquisite structures and processes as being exactly what a great intelligence would design.

Indeed, if we look at the wings of swallows and of hummingbirds, without any kind of detailed morphological and ontogenetic analysis, one might simply resort to “form follows function,” wholly within the design context in which that statement has typically been made.  Or, if we were to consider the cliche more closely, we might conclude that in our experience function is first considered and analyzed, and form is then designed and specifically articulated in order to fit that function. 

Yes, that is our experience, thus it is not altogether unreasonable for people who know only design processes to think that wing articulations must then have been designed.  But as biologists know all too well, that is not what we see in life.  More than once I’ve brought up the question of why all vertebrate wings are modifications of their ancestors’ legs, while human-designed wings are modifications of bird wings as well as having been partly designed from first principles.  The answer is all too clear, which is that vertebrate wings simply evolved, and were not designed in any manner as we would expect of an intelligence operating to produce them.

Yet the overlap between design and evolution is good enough for us to use bird wings as the basis for design, as the Chinese did with their kites (which is the origin of humanity’s airfoils–or so I have been led to believe), and as the Wright brothers did after adopting previous airfoils, and by studying birds and their flight abilities on their own.  So surely one must address such an overlap, partly to understand evolution, partly to understand design.

The short answer is that intelligence and design expand on what evolution (otherwise) provides.  But this answer itself requires expansion.  Probably a large part of the evolution of logic and rationality comes from the fact that intelligence adapted to an environment which in important ways is not the result of evolution at all.  This goes back to what many people understand, the fact that mathematics–especially geometry–and cognitive abilities such as following straight lines and succession, are to a large extent ways of dealing with space and also with time.  Straight lines happen to be efficient ways to get from one point to another one, hence animals tend to travel in straight lines, and predators learn that this is the case–until avoidance maneuvers kick in, that is.

Primates are believed to have evolved intelligence partly for the sake of spatial (and temporal) understanding, particularly as arboreal organisms operating within 3-D space and dealing with 3-D objects (of course all space and objects are 3-D, but lions do not need to be nearly as aware of the three-dimensionality of their plains and prey).  Social living extended this intelligence to models of complex organisms and their behaviors, so that we became able to understand what another primate (or prey) is likely to do next.  And at some point, primates began to use various spatial items in their surroundings to manipulate their surroundings, and a (usually fairly straight) stick extended the reach of the (usually fairly straight) forearms of the primate.  It should be noted in passing that the fact that we use intelligence to understand other animals and their “purposes” is likely a big reason why many people simply assume that the forms and functions of organisms ought to be understood according to purpose–if not the purpose of an observable being, then the purpose of an unobservable being.

Yet intelligence operates quite differently than evolution, which is why using a stick can effect a quantum leap over what the little primate can do with its arms alone.  Or, more importantly, from understanding evolution and its overlap with design, a stick which evolved simply to uphold leaves above other plants for a competitive advantage eventually becomes an extension of the animal’s spatial capabilities, so that increasing the extension of one’s reach is no longer tied to ancestry and the tedious and slow evolutionary growth of a primate’s arm. 

Oddly (and seemingly cluelessly in the case of Behe), this gets back to what Behe stated in Darwin’s Black Box, that Darwinian evolution requires physical precursors, while design can make do with conceptual precursors.  And indeed, that is exactly why we understand life to be the result of “Darwinian evolution,” for it is incapable of conceptualizing a line, or of taking up a stick to bridge the chasm between two organisms.  Evolution is quite limited while dealing with the geometries of space and of designed machinery (aside from the evolution of intelligence), and it can only respond with logical brains to do what evolution could never do directly.

One could look at evolution as incrementally (if not always incrementally, overwhelmingly so) providing the forms which most animals use, while intelligence evolved to use these forms and abilities well in unevolved time and space.  Thus, intelligence has evolved to understand organisms’ forms and functions (their own, and, in many cases, those of other species) in a spatial and temporal manner that is completely foreign to how evolution processes information, and it can even adopt and extend the spatio-temporal capabilities artificially.  Indeed, intelligence in humans can do what evolution could never do.

The fact is that bird wings have their forms because even legs are plastic over millions of years.  But bird, bat, and pterosaur, could never have come up with wings by rearranging, say, ribs into the proper form to make wings.  We can.  Or, like the Wright brothers, we can take trees (separated from us by hundreds of millions of years of evolution) and saw out exactly the parts needed to make an airfoil, and even to articulate this airfoil so that it can change shape somewhat like a bird wing can.  Rationality can leap past inheritance, in other words, while evolution could never come up with an aluminum engine, or any such thing, yet which the Wright brothers used to power their airplance.

It should be noted also that the aluminum–and the steel–in the engine used to power the Wright brothers’ airplane, along with the design of the engine, come almost entirely from the intellect, with not even an evolutionary conceptual precursor like the wings.  Intelligence evolved to analyze, and even to synthesize, articulations and ideas, so that wholly new things, like aluminum engines, could be thought up in the primate brain.  This is nothing like what evolution does, which is why we distinguish designed objects from living objects both by the formers’ conceptual leaps (which may not be altogether rational), and by the almost inevitable rational aspects which exist within intelligently-designed objects.

Notably, all intelligence of which we know is inextricably tied to evolution.  While evolution itself could never directly supply the leaps of logic and articulation used to analyze a bird carcase, or to create a spear with a pointy stone on the end of it, both evolution and development can shape the rational and communications abilities within animals (primarily humans, on this planet) to actually deal with knowledge of space and of bird articulations, and thus to enhance survival in this world through intelligence.  Intelligence overlaps with evolution both because it is selected to understand animals of one’s own and also of other species, and because it extends and enhances the behaviors of organisms.  This seems to be true to the degree that humans have actually lost many earlier behaviors and even innate capabilities, instead relying more upon intelligence itself to supply behaviors that once evolved to exist and then evolved not to exist.

Another reason for the overlap of the products of design and of evolution is simply that many of the same forms and articulations are needed simply to provide function, or at least to provide function at minimal cost.  While we may have copied airfoils from birds initially, the airfoil on a supersonic airplane owes little to any organism (except for the original idea), rather it is developed from empirical and theoretical studies.  Intelligence did there what evolution could never do, since the latter cannot provide the power needed for supersonic flight.  That said, subsonic planes have airfoils not unlike those of bird wings, not because we’re unable to think beyond copying bird wings for subsonic flight, but because millions of years of evolution, and 100 years of intelligent design, come to basically the same solution–because there really is only one good solution (and varieties of that solution to fit different criteria for flight–which are seen in both planes and in birds).

So one of the main reasons for the overlap between design results and evolutionary results is rather prosaic and probably obvious to most who think about it–good solutions are typically few, and both evolution and design can reach many of these solutions.

Nevertheless, the differences between evolutionary processes and intelligent processes are considerable, and the limitations of evolution are severe.  We can turn a tree into the body (if not the engine) of an airplane.  But only animals with articulated limbs of roughly the right position and tolerably within striking distance of a wing will ever evolve wings.  Even more apparent, evolution will not cause organic life-forms to evolve aluminum wings and piston engines to produce flight, while evolved intelligence has done so.  Likewise, one should remember that evolution has a kind of “parallel processing” power that, albeit only over very long periods, produces wing control that human designers continue to envy.  This seems to be in part because “evolvability evolves,” so that organisms can slowly change to exquisitely fit niches, like those that birds inhabit.

Finally, then, the question in biology comes down not to why evolutionary and intelligent solutions overlap meaningfully, since they would have to in order to produce functional “machinery.”  The real question is why biological solutions are at once so limited when compared to intelligent design, and, very often, so much more exquisite, despite their limitations.  Of course the answer is that the gradual change which predominates over the course of biological evolution can make no spatial, temporal, or rational leaps, while it refines the modifications that it does effect with a profligacy (of offspring), and via excruciatingly fine changes that is not at all easy for our rather blunt rational abilities to effect.

The limitations of evolution and the strengths of evolution are explained only in one way, through the natural selection of variations in organisms, for small modifications of the immediately preceding inheritance of organisms are the mill that grinds bird, bat, and pterosaur wings into such superb and beautiful shapes, while simultaneously preventing the adoption of unrelated forms or with any consideration of first principles.

The only way that evolution could ever produce an aluminum engine, or a wooden skeleton of an airfoil, is by evolving the spatial, temporal, and rational capacities of intelligence.  That is why no vertebrate wing has been anything but the modified forelimbs of its ancestors (unless, again, we count the flying fish, which evolved gliding wings from the precursors to tetrapods’ forelimbs, the pectoral fins), while intelligence–once it evolved and developed culturally and technologically–made a huge number of leaps in capability never before seen in life.  

In addition, this is why most of the ancients differentiated considerably between life and technology, not only because technology is inferior in many ways to life, but because even then technology was startlingly superior in other ways.

Unfortunately for evolution-deniers, exquisite and complex adaptations of a very limited range of forms is exactly what is expected of evolution, and not at all what is expected of design.  Or, to put it into their terms, of course designers adopt and adapt solutions from life, for human intelligence both analyzes and synthesizes.  The insurmountable problem for them is that life never adapts anything from an unrelated and separate (with no, or very limited, lateral transfer of genes) lineages or from first principles, abilities that an actual intelligent designer is expected to have.

This is part of a series of posts that I am combining into one long post, which may be found at Darwin’s Black Box.

What is ID’s efficient cause?

October 29, 2008

IDists are keen to return Aristotle’s “final cause” to the sciences, or at least to biology (see Dembski, for example).  Which is rather sad, because they can give us no evidence for the purpose of organisms, instead they wish to insist that life “had to be designed” and thus has purpose.  One has to wonder what good that would be to know, since we would still need to be able to discover purpose for it to impact us, and ID has never been able to demonstrate any purpose (to be sure, nearly all IDists have sacred writings in mind to provide specific purpose, but will not admit it in their supposed science).

So OK, they want final causes (aside from those of animals such as humans), and perhaps formal and material causes as well, but where is their “efficient cause”?  That is the closest that Aristotle’s “causes” (aitia, which probably would translate better as “reasons” than “causes”) come to fitting with scientific causation in the classical realm, they do not deny the importance of efficient causes, and yet they have none whatsoever.

It should be noted that Aristotle was not one who simply called “intelligence” or “design” the cause or the reason (not of a manufactured item, that is), the aition, because intelligence is just a faculty, and design is merely a category of actions or “causes”.  Thought using intelligence might be a cause, and design may be part of a specific process, but simply invoking intelligence, thought, or design would explain nothing by themselves.  There is an apparent exception to Aristotle’s “efficient cause” as a specific cause or set of causes, which is God the unmoved mover–a very indefinite “cause”–but even IDists don’t appeal to such ancient fictions, partly because it would too readily reveal the religious motivation behind ID.

Aristotle has these things to say of the “efficient cause”:

Again (3) the primary source of the change or coming to rest; e.g. the man who gave advice is a cause, the father is cause of the child, and generally what makes of what is made and what causes change of what is changed.

e.g. both the art of the sculptor and the bronze are causes of the statue. These are causes of the statue qua statue, not in virtue of anything else that it may be-only not in the same way, the one being the material cause, the other the cause whence the motion comes.

All causes, both proper and incidental, may be spoken of either as potential or as actual; e.g. the cause of a house being built is either ‘house-builder’ or ‘house-builder building’.

In investigating the cause of each thing it is always necessary to seek what is most precise (as also in other things): thus man builds because he is a builder, and a builder builds in virtue of his art of building. This last cause then is prior: and so generally.

Further, generic effects should be assigned to generic causes, particular effects to particular causes, e.g. statue to sculptor, this statue to this sculptor; and powers are relative to possible effects, actually operating causes to things which are actually being effected.  Aristotle’s Physics

In a scientific sense, this is all rather imprecise.  But even Aristotle’s generic causes, such as “the art of building,” is far more precise and meaningful than anything we have gotten out of ID as an efficient cause.  Dembski even makes “efficient cause” more precise than Aristotle does:

The efficient cause is the immediate activity that produced the statue–Michelangelo’s actual chipping away at a marble slab with hammer and chisel.  Dembski

Dembski’s example of an efficient cause moves us closer to scientific causation, and is a typical example used by those who are explaining Aristotle’s “four causes”.  Despite the fact that he waffles on mechanism in that article–and attacks the strawman of design being “barred from the content of science” (has any archaeologist tried to explain pottery without intelligent agents involved somehow?)–he is still hardly consistent when he makes statements such as this one:

You’re asking me to play a game: “Provide as much detail in terms of possible causal mechanisms for your ID position as I do for my Darwinian position.” ID is not a mechanistic theory, and it’s not ID’s task to match your pathetic level of detail in telling mechanistic stories. Notorious Dembski comment

Ah yes, Dembski has neither evidence for a final cause, nor for an efficient cause.  Likewise with Behe, who pretends to take a more scientific approach than Dembski, he will not even commit to the specificity that an ancient thinker like Aristotle would:

Another problem with the argument from imperfection is that it critically depends on a psychoanalysis of the unidentified designer.  Yet the reasons that a designer would or would not do anything are virtually impossible to know unless the designer tells you specifically what those reasons are.  One only has to go into a modern art gallery to come across designed objects for which the purposes are completely obscure (to me at least).  Features that strike us as odd in a design might have been placed there by the designer for a reason–for artistic reasons, for variety, to show off, for some as-yet-undetected practical purpose, or for some unguessable reason–or they might not.  DBB, 223

What, people refuse to call something like that science?  Notice how desperate he is to claim no distinguishing marks of design (since he knows that these are lacking from life that we have not engineered) that he goes to deliberately obscure art as his “example.” 

Yet in the first and second Dembski links (to the same source), it is argued, against a strawman, that design is readily detectable.  To be sure, he misunderstands his own sci-fi analogy as the search for “complex specified information,” when in fact it was rationality behind the signal that indicated intelligence.  Dembski explaining what was detected in the movie Contact:

In this sequence of 1126 bits, 1’s correspond to beats and 0’s to pauses. This sequence represents the prime numbers from 2 to 101, where a given prime number is represented by the corresponding number of beats (i.e., 1’s), and the individual prime numbers are separated by pauses i.e., 0’s).  Dembski

Yes, that’s right, it isn’t complexity that is discovered (Dembski calls unlikely simplicity by the name “complexity,” a distortion even of the meaning of the term), it is rationality.  Even Behe gets it slightly, and ludicrously brings up rational agents:

Rational agents can coordinate pieces into a larger system (like the ship) to accomplish a purpose.  Edge of Evolution, 168

Yes, and the context from which that comes has any number of rationally-devised artifacts being discovered.  Nevertheless, note how carefully he words it, to avoid the implication that life ought to appear rationally designed if it was intelligently designed.  He’s still relying on evident “purpose,” which he deliberately tried to avoid as a test of “design” in the previous quote.  There, too, he wrote of “reasons” for design, as he denied their visibility, suggesting that he knew very well that he was denying that purpose is evident in life, while in this later quote he is trying to suggest that rationality is found exactly through evident purpose (as he had also done in DBB, prior to denying it in order to avoid predicting evident purpose in life–in response to those who noted exactly the lack of purpose in so many aspects of life).

The fact of the matter is that both Dembski and Behe do not wish “design” to be tested by evidence of purpose, for they know that, for instance, malaria pathogens do not seem to fit any kind of evident purpose.  They bring up purpose in order to ignore efficient causation and the rationality typically evident behind such causation (even if some art is hard to figure out, the rationality of the frames betrays intelligence via rational efficient causation).  Likewise, they totally avoid efficient causation, for as I previously argued, they have no causes at all, only unconstrained accident (or whim).

Evolution is also fraught with accident (see link above), but these are “lawful accidents,” of the kind that are permitted and even (probabilistically) predicted.  We have “efficient causation,” or more exactly, scientific causation.  And what is interesting to note is that while Dembski and Behe contradict themselves and each other with their “arguments,” primarily because they can show no “intelligent design” causation whatsoever, earlier ID really did mean to find the marks of intelligence and rationality in life:

…We allege, that the same principle of intelligence, design, and mechanical contrivance, was exerted in the formation of natural bodies, as we employ in making of the various instruments by which our purposes are served […]. William Paley

Paley was looking for efficient cause (see also pp. 8 & 233 of the above link for his criticisms of explanations lacking in efficient causes), and for observable purpose.  Behe and Dembski contradict themselves on these matters, while generally trying to smuggle “purpose” in via “complexity.” 

Paley’s ID was tolerably close to a scientific hypothesis–which Darwin took seriously.  By avoiding all causes (even the ones they bring up, like “purpose”–Aristotle’s “final cause”), the current crop of IDists cannot even match Paley’s now-failed “science,” nor even keep from contradicting themselves as they both claim that purpose and rationality are evident, and that they are not.

This is part of a series of posts that I am combining into one long post, which may be found at Darwin’s Black Box.

Horizontal transmission of a transposon in animal species

October 22, 2008

Here is the core of the article, in my opinion:

The fact that invasive DNA was seen in a bush baby but not in any other primates, and in a tenrec but not in elephants, hints that something more exotic than standard inheritance is going on.

However, this patchy distribution by itself does not rule out the traditional method, as some of the species could have lost the transposon DNA throughout evolutionary history.

So the team looked at the position of the hAT transposon – if it had been inherited from a common ancestor it would have been found in the same position, with respect to other genes, in each species. But they could not find a single case of this.

Since first entering the genome, the hAT has been able to reproduce dramatically – in the tenrec, 99,000 copies were found, making up a significant chunk of its DNA. Feschotte speculates that this must have had a dramatic effect on its evolutionary development.

“It’s like a bombardment”, he says. “It must have been evolutionarily significant because the transposon generated a huge amount of DNA after the initial transfer.”

Feschotte says he expects many more reports of horizontal gene jumping. “We’re talking about a paradigm shift because, until now, horizontal transfer has been seen as very rare in animal species. It’s actually a lot more common than we think.”  New Scientist

“More” is probably a good bet, all right, but horizontal transmission of genes is still not all that common in animals, so far as we can tell.  Still, 99,000 copies is bound to have made a difference in the evolution of the tenrec.

I thought the story itself was interesting, but it also has elements in its discovery that demonstrate how out-of-the-ordinary animal genetics can be and is discovered.  IDists sometimes like to point to the fact that this or that scientist agrees that design could be detected. 

But that’s their entire problem, it could be detected and it never is.  Meanwhile, science continues to find “non-canonical” changes and evolutionary patterns, such as this gene being laterally transferred into animal genomes.  It is entirely a matter of what has evidence and what does not.  Vertical transmission is by far the dominant form of gene transmission in, say, vertebrate species, as indicated by both conserved genes and by the lack of commonality after taxa diverge.  Horizontal transmission occurs, and is identifiable by its “lawfully accidental” appearance in unrelated species, as well as by the fact that the gene is not found in the same places in the genomes of the animals having a particular gene.

Now if we could ever find the commonality of authorship in any evolutionary development, such as older IDists predicted, ID would at last have some evidence in favor of it.