"Are the Mechanisms that Produce Phenotypic Variation "Random"?

Some "intelligent design" supporters have recently asserted that all of the 47+ mechanisms listed in my blog are “random” or “accidental", and therefore the old creationist argument that "RM & NS" doesn't explain the origin and evolution of life is still valid. However, this is simply not the case. On the contrary, a large percentage of these mechanisms are the result of processes that are not “random” by any reasonable definition of that term. I have repeatedly been very careful to point this out, but that clearly has been missed by many "intelligent design" supporters.

It is also not the case that the 47+ processes are not “guided". Indeed they are “guided”, by the various internal and environmental forces that produce both the variations and the various evolutionary mechanisms that operate upon them (i.e. natural selection, sexual selection, founder effects, genetic bottlenecks, neutral “drift” in deep evolutionary time, exaptation, heterochronic development, changes in homeotic development, interspecific competition, species-level selection, serial endosymbiosis, convergence/divergence, hybridization, phylogenetic fusion, background and mass extinction/adaptive radiation, and internal variance).

That said, however, it is also demonstrably the case that none of the mechanisms listed above can be shown empirically to be “foresighted". Indeed, the whole idea of “foresightedness” in natural processes seems to me to violate several very well-established principles of physics, including the Second Law of Thermodynamics.

How can any natural process be empirically shown to be genuinely “foresighted"? Do rocks fall “in order to” reach the ground? Do gas molecules move “in order to” produce the phenomena we describe with Boyle’s Law? Do the electrons in the valence energy shells of hydrogen and oxygen form shared couplets “in order to” produce water? Do particular genetic changes happen “in order to” produce phenotypic changes that have no effects on organisms’ survival and/or reproduction now, but might have in the future? And how can anyone show any of these to be the case?

It is important to note that the terms “foresighted” and “goal-oriented” are not equivalent. The latter term is entirely compatible with both physics in general and evolutionary biology in particular. Indeed, the genomes of all living organisms are “goal-oriented programs” (as most clearly pointed out by Ernst Mayr), in that they organize and control the assembly and operation of the living organisms for which they code.

However, the processes by which such genomes have come into being (i.e. the 47+ mechanisms listed here, operating through the various mechanisms of micro- and macroevolution listed above) have not been empirically shown to be either “foresighted” nor “goal-oriented". It seems to me that this would be extremely difficult, if not impossible to do. What kinds of empirical observations could one conduct that would unambiguously verify today that some component of an existing organism’s genome or phenome was present in that organism now because at some point in the future it might become necessary for that organism’s survival and/or reproduction?

Clearly, once an organism has survived and/or reproduced one can point to its various attributes and say “yes, that attribute appears to have contributed to the organism’s survival/reproduction". However, that is no more evidence of “foresightedness” than a lottery winner saying “I chose these lottery numbers (or bought those particular scratch-off tickets) because I knew they would be winners". This is known as the “fallacy of affirming the consequent” (also called post hoc, ergo propter hoc argumentation) and is logically inadmissible in the natural sciences.

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

--Allen

D'Arcy Thompson and "Front-Loaded" Intelligent Design

AUTHOR: Salvador Cordova

SOURCE: Marsupials and placentals: A case of front-loaded, pre-programmed, designed evolution?

COMMENTARY: Allen MacNeill

The concept of "front-loading" as described in Salvador Cordova's post at Telic Thoughts bears a remarkable resemblance to the ideas of the Scottish biomathematician D'Arcy Thompson (1860-1948). In his magnum opus, Growth and Form, Thompson proposed that biologists had over-emphasized evolution (and especially natural selection) and under-emphasized the constraints and parameters within which organisms develop, constraints that "channel" animal forms into particular patterns that are repeated over and over again across the phyla.

However, while Thompson's ideas strongly imply that there is a kind of teleology operating at several levels in biology (especially developmental biology), Thompson himself did not present hypotheses that were empirically testable (sound familiar?):

Thompson did not articulate his insights in the form of experimental hypotheses that can be tested. Thompson was aware of this, saying that 'This book of mine has little need of preface, for indeed it is 'all preface' from beginning to end.'

Thompson's huge book (over 1,000 heavily illustrated pages) is a veritable gold mine of ideas along the lines articulated in Sal's post. However, Thompson's underlying thesis is just as inimical to ID as is the explanation from evolutionary biology. His argument is essentially that biological form is constrained by the kind of mathematical relationships that characterize classical physics. That is, there are "built-in" laws of form that constrain the forms that biological organisms can take. And therefore, physical law provides the “front-loading”, not a supernatural “intelligent designer.”

For example, Thompson pointed out that the shape that droplets of viscous liquid take when dropped into water are virtually identical to the medusa forms of jellyfish, and that this "convergence of form" is therefore not accidental. Rather, it is fundamentally constrained by the physics of moving fluids, as described in the equations of fluid mechanics. Thompson's book is filled with similar examples, all pointing to the same conclusion: that biological form is constrained by the laws of physics (especially classical mechanics).

Evolutionary convergence, far from departing from Thompson's ideas, is based on essentially the same kinds of constraints. Sharks, dolphins (the fish, not the mammals), tunas, ichthyosaurs, and porpoises all appear superficially similar (despite significant anatomical differences) because their external shapes are constrained by the fluid medium through which they swim. In the language of natural selection, any ancestor of a shark, dolphin, tuna, ichthyosaur, or porpoise that (through its developmental biology) could take the shape of a torpedo could move more efficiently through the water than one that had a different (i.e. less efficient) shape, and therefore would have a selective advantage that would, over time, result in similar shapes among its proliferating ancestors. The same concept is applied to the parallel evolution of marsupial and placental mammals: similar environments and subsistence patterns place similar selective constraints on marsupial and placental mammals in different locations, resulting in strikingly similar anatomical and physiological adaptations, despite relatively non-homologous ancestry.

This evolutionary argument is now being strongly supported by findings in the field of evolutionary development ("evo-devo"), in which arguments based on "deep homology" are providing explanations for at least some of the seemingly amazing convergences we see in widely separated groups of organisms. Recent discoveries about gene regulation via hierarchical sets of regulatory genes indicate that these genes have been conserved through deep evolutionary time, from the first bilaterally symmetric metazoans to the latest placental mammals, as shown by their relative positions in the genome and relatively invariant nucleotide sequences. These genes channel the arrangement of overall anatomy and body form throughout the course of development, producing the overall shapes of organisms and the relationships between body parts that we refer to when discussing evolutionary convergence.

However, as should be obvious by now, this in no way provides evidence for the currently popular ID hypothesis of “front-loading”, except insofar that it states that the hierarchical control of overall development evolved very early among the metazoa. It provides no empirically testable way to distinguish between an evolutionary explanation and a “design” explanation. Indeed, all of the evidence to date could be explained using either theory.

And so, by the rules of empirical science, since the evolutionary explanation is both sufficient to explain the phenomena and does not require causes that are outside of nature (i.e. a supernatural designer, that is neither itself natural nor works through natural – i.e. material and efficient – causes), evolutionary biologists are fully justified in accepting the evolutionary explanation (and disregarding the “front-loaded ID” explanation.

Only in the case that the kinds of natural causes described above (especially the ability of evo-devo processes to constrain the development of overall form via purely natural means via the known biochemistry of development) can NOT explain the patterns we observe in convergent evolution should we entertain other hypotheses (especially if those other hypotheses are not empirically testable). Only then, and not before…and therefore certainly not now.

FOR FURTHER READING:

For more on Thompson and his work, see:
http://www.google.com/search?hl=en&q=D%27Arcy+Thompson&btnG=Google+Search
and especially:
http://www-history.mcs.st-andrews.ac.uk/Mathematicians/Thompson_D'Arcy.html
and follow the links at:
http://en.wikipedia.org/wiki/D'Arcy_Thompson

Also, a thread that included a discussion of Thompson's work has already appeared at Telic Thoughts http://telicthoughts.com/?p=763

--Allen

Is Intelligent Design Distinguishable from Deism?

SOURCE: Dispatches from the Culture Wars

COMMENTARY: Allen MacNeill

There is a very interesting thread at Dispatches from the Culture Wars on the difficulty (and importance) of distinguishing between deism and "intelligent design theory (IDT)." Specifically, there is a long discussion between several posters on whether IDT is fundamentally different from “theistic evolutionary theory (TET)” (which is, IMO, indistinguishable from simple deism).

In particular, several of the posters have argued that if IDT and TET are equivalent, then there is literally no science in IDT at all. That is, if God (remember, as I have posted earlier, it’s easier and more intellectually honest to type "God" than “the intelligent designer”) created the universe with just exactly the right set of natural laws that things like the bacterial flagellum could have evolved by purely natural processes alone (i.e. without further supernatural intervention), then that version of IDT is indistinguishable from deism (DEI). In that event, both would be entirely without scientific value, since both IDT and DEI would thereby accept the operation of all natural laws as both necessary and sufficient to produce all natural objects and processes.*

This means that if we are to distinguish between IDT and DEI (and, by extension, from TET) it must be incontrovertably shown that natural laws as they now exist are insufficient to produce existing natural objects and processes. As many others have pointed out, this requires proving a negative. That is, unless we assume that all currently known natural laws are literally all there are or even can be (as Lord Kelvin infamously did at the end of the 19th century), then it is possible that in the future new versions of purely natural laws will be discovered that can explain the existence of those entities now claimed to be possible only through supernatural intervention.

This, of course, leads to all kinds of logical fallacies, chief among them the problem of “supernatural incompetence.” If IDT = DEI = TET, then God is indeed omnipotent and can create natural laws that make the evolution of all natural entities possible without further intervention. In that case, IDT, DEI, and TET are indistinguishable from each other and none add anything of use to the generally accepted methods and principles of empirical science. This means that nothing more need be said about them by scientists, and we can go on doing science (including evolutionary biology) the way we have been doing up until now.

However, if IDT is not DEI nor TET, then perforce God must not be omnipotent. That is, He cannot create a set of natural laws that can in the fullness of time produce the objects and processes we observe around us.

Therefore, it seems to me that there are only two logical positions to take on this subject:**

1) God is omnipotent and therefore created the universe with natural laws of sufficient power and subtlety to allow purely natural processes to produce all natural objects (and therefore IDT is unnecessary).

or

2) God is not omnipotent and therefore cannot create a universe in which natural laws are sufficient to produce all natural objects and processes. This means that God (who is, by definition, incompetent) must intervene at specific times and places to alter nature in direct contravention of His originally created (and incompletely effective) natural laws.

These two positions have obvious and devastating implications for theology as well:

If (1) is the case, then God is only relevent to nature during it creation. From then on, He does not participate in it in any material way (and therefore prayer is useless, as all intercession by God violates His original created order), or

If (2) is the case, then God has left incontrovertable evidence of both His existence and actions in the structure of nature itself, and therefore faith is no longer necessary (and both justification and salvation through faith are pointless).

--Allen

*It also seems that this version of deism is indistinguishable from what some ID theorists (including Michael Behe) are now referring to as "front-loaded" IDT (FLIDT). That is,

FLIDT = DEI = TET

all of which are irrelevent for and useless to science.

**Alert readers may notice that there is a third option: God is omnipotent, but chooses to create a universe in which His natural laws are insufficient to produce all natural objects and processes without his intervention. This strongly implies that God is either meddlesome or capricious (or both), conclusions that I suspect would not be palatable to most ID theorists, deists, or theistic evolutionists.