Tag: jerry coyne

Can the supernatural be studied? Kiri-kin-tha’s first law of metaphysics

May 18, 2009 • 9:37 pm

by Greg Mayer

A tactic pursued vigorously by cdesign proponentsists is to claim that scientists assume that God (and other supernatural beings) doesn’t exist, and that this assumption is just that: an assumption, with no empirical basis. Roger Pennock has responded to this claim, most notably in his book Tower of Babel, noting that it confuses metaphysical naturalism (claims about the existence of entities) with methodological naturalism (forgoing explanatory appeals to the supernatural, because such appeals squelch further inquiry), and that all science must adopt the latter, lest it give up investigation whenever a problem proves recalcitrant. Its converse, “methodological supernaturalism”, is essentially a God of the gaps argument: what we do not understand, we attribute to the supernatural.  The fallacy of this argument has been known for millenia, and it has perhaps never been better said than by Hippocrates:

Men think epilepsy divine, merely because they do not understand it. But if they called everything divine which they do not understand, why, there would be no end to divine things.

It’s also always seemed to me a rather parlous position for a religious person to adopt, because by identifying the works of God with ignorance, the realm of the divine is on a continual retreat before expanding knowledge. A weaker but related claim made by some accommodationists is that science must be silent about existential claims about God(s), because it cannot contemplate supernatural entities, being bound to consider only natural explanations.

I think Pennock’s response is compelling, but I’ve always thought more could be said.  Is it really true that science cannot investigate the supernatural?

If the goal of science is identified, as it sometimes is, as the explanation of phenomena by recourse to general laws (or some such formulation) then it would appear that supernatural events or entities, being unbound by such laws, could not be scientifically investigated. While this characterization of science is not without merit, it ignores a large part of science– much of astronomy, geology, and biology, for starters– which is concerned with history: what has happened.  They are, as R.J. O’Hara has put it, “those sciences which have as their object the reconstruction of the past based on the evidence of the present.”

For these sciences, supernatural events are not beyond their ken. For if supernatural entities have interacted with the world in a way to produce observable effects (and if they have not, then to posit their existence is vain), then we can surely know of them by the methods of the historical sciences.

In light of the latest box office smash, an example from Star Trek is enlightening.  In the Next Generation and some later series, the crew of the Enterprise periodically encountered a being called Q. Q is immortal and apparently omnipotent: he can do anything. The source and nature of his power is unknown to the Federation or any other galactic civilization.  But was he supernatural? Well maybe in some sense he was, but in another sense he wasn’t: he could be observed, studied, and recorded by all the normal biological senses and scientific instruments.  His actions were known, recorded, and part of documented history. His activities were never explained by general laws, but that his activities took place was well attested.  So although he was not (at least yet) a subject of the sciences of general laws, he was certainly a subject of the historical sciences.

That the supernatural, as exemplified in my example by Q, is not unstudiable, has been proposed in a piece by Russell Blackford and in one of Jerry’s pieces in The New Republic.

But if any supernatural entity in observable contact with the world (i.e. a contact that has consequences) can be studied by the methods of the historical sciences, even if the effects of its contact cannot be subsumed under general laws, is it still supernatural? I would say no. To back me up on this I call on the great Vulcan philosopher, Kiri-kin-tha, and his first law of metaphysics:

Nothing unreal exists.

Or, as I would rephrase his law, anything which exists is natural.

WEIT reviewed in Christian Science Monitor

March 16, 2009 • 2:45 pm

by Greg Mayer

Why Evolution is True receives a favorable review today in the Christian Science Monitor from Todd Wilkinson.  Money quote:weit-cover1

Coyne methodically lays out the complete trail of evidence supporting evolution, ranging from the fossil record of dinosaur bones to sophisticated DNA analysis, and many decades of rigorous peer-reviewed scrutiny in between.

In this 200th anniversary year of Darwin’s birth, “Why Evolution Is True” ranks among the best of new titles flooding bookstores….

He makes the case for evolution in a way that is eminently understandable, colorfully articulated, and relevant to our time.

Update: Jerry and I were apparently writing posts on this review simultaneously, so I didn’t see his post till mine went up.  If I knew how to delete a whole post I would, but I don’t know how!

Caturday felid

March 14, 2009 • 5:20 pm

by Greg Mayer

Until Jerry settles back in there’ll be a bit of overlap in our posting, so I’m providing this Caturday’s felid. Actually it’s two felids: the lion and the tiger (both of these links come from a wonderful page maintained by Virginia Hayssen of Smith College), both photographed today at the Racine Zoo in Wisconsin.

Two young lions at the Racine Zoo

The tiger, unfortunately, sat back out of useful range of the camera I had with me, so I had to settle for this.

Tiger sign at Racine Zoo

In captivity hybrids between lions and tigers, called ligers (male lion X tigress) and tigons (male tiger X lioness), can be produced, which are healthy and vigorous.  As Jerry explains in chapter 7 of WEIT, species are defined by their reproductive relationships: members of the same species will interbreed with one another, while members of different species are kept from successfully reproducing by one or more reproductive isolating barriers. Why, then, do we consider lions and tigers different species?

Most people think of lions as being from eastern and southern Africa, but within historic times lions ranged across north Africa and southeastern Europe through southwest Asia to northern India.  One population of Asiatic lions still survives, in the Gir Forest, closely protected by the Indian government.

Historic distribution of the lion in north Africa, Europe, and Asia

Tigers were widespread in Asia, from the Caucasus to Siberia in the north and Java and Bali in the south. Until man began to decimate them, lions and tigers broadly overlapped in southern Asia, but remained distinct, without interbreeding. Thus, in nature, lions and tigers did not interbreed. And the full definition of a species, given by Ernst Mayr in 1940, is that species are groups of actually or potentially interbreeding populations in nature, reproductively isolated from other such groups.

Scientific integrity

March 9, 2009 • 2:15 pm

by Greg Mayer

Jerry had written earlier about a piece in the New York Times by Dennis Overbye heralding the restoration of science to its rightful place promised by President Obama in his inaugural address.  I, too, was thrilled when I heard the new president’s words while watching the speech with a throng of travellers at an airport bar in Philadelphia. Perceptively, Overbye wrote, “Science is not a monument of received Truth but something that people do to look for truth.”

Well, the search for truth by the federal government has resumed. Having reversed or modified some specific Bush administration policies, Obama has now issued a general memorandum on scientific integrity:

Science and the scientific process must inform and guide decisions of my Administration on a wide range of issues, including improvement of public health, protection of the environment, increased efficiency in the use of energy and other resources, mitigation of the threat of climate change, and protection of national security.

The public must be able to trust the science and scientific process informing public policy decisions.  Political officials should not suppress or alter scientific or technological findings and conclusions.  If scientific and technological information is developed and used by the Federal Government, it should ordinarily be made available to the public.  To the extent permitted by law, there should be transparency in the preparation, identification, and use of scientific and technological information in policymaking.  The selection of scientists and technology professionals for positions in the executive branch should be based on their scientific and technological knowledge, credentials, experience, and integrity.

Update: From Obama’s statement on stem cell research, a clear sign that he understands how research goes, and what a “miracle” is:

Medical miracles do not happen simply by accident. They result from painstaking and costly research, from years of lonely trial and error, much of which never bears fruit, and from a government willing to support that work.

The palimpsest theory

March 8, 2009 • 9:01 pm

by Greg Mayer

One of the things Jerry mentioned in introducing me was that I had coauthored, with my late friend and mentor John A.W. Kirsch, a paper entitled “The platypus is not a rodent”.  While there’s a certain pure amusement value in such a title (which alludes to a series of papers concerning the relationships of guinea pigs with titles such as “Is the guinea-pig a rodent?”,  “The guinea-pig is not a rodent”, and “Are guinea pigs rodents?”; btw, the guinea pig is a rodent, and the platypus is an egg-laying monotreme, nowhere close to rodents), Jerry might have mentioned the paper because of its subtitle: “DNA hybridization, amniote phylogeny and the palimpsest theory”. In WEIT, Jerry likens the bodies and genomes of organisms to palimpsests. In ancient and medieval times, parchment to write on was expensive, but writing was cheap. To save parchment, the writing would be scraped off a book (for in those days, all books were written by hand), and a new book written over the old. Such reused parchments are called palimpsests. The original writing, however, can often be seen or retrieved, and thus the history of the parchment’s uses can be inferred from the existing parchment. (Here’s an example mentioned by Jerry.)

A palimpsest possesses both recently acquired features (the new writing) and remnants of old features (the old writing).  So do organisms. They possess immediately adaptive characters, as well as characters from earlier in their history.  This has long been recognized, and the analogy with palimpsests has been explicit. In 1910 W.K Gregory of the American Museum of Natural History made a distinction between ‘caenotelic’ and ‘paleotelic’ characters; he later called these ‘habitus and heritage’ (Gregory was the major professor of my major professor, E.E. Williams, and thus I am Gregory’s academic ‘grandson’). In 1947, Gregory christened his ideas the ‘palimpsest theory’.  As John and I explained:

Habitus characters (equivalent to caenotelic features) become in time transformed into, or at least included among, those of heritage as the collected adaptive wisdom of the lineage at more general levels, by a process of sequential adaptation …. Habitus and heritage are thus ‘correlative terms’, so that ‘the remainders of the successive habitus of the remote ancestors become incorporated into the heritage of later times’ (Gregory 1947, p. 8). Heritage features are therefore of utmost importance in determining the broad affnities of a higher-category taxon, because they may be ones shared with a similarly inclusive but different group.

Thus the habitus characters are the new writing, the heritage the old. The palimpsest analogy had been published earlier by the great South African paleontologist Robert Broom (best known for his later work on australopithecines, the predecessors of our own genus, Homo) who in 1924 wrote about turtles that

Unfortunately members of the order are all extremely specialized and in some respects degenerate, so that the picking out of the ancestral [=heritage or paleotelic] characters amid the more recent specializations [=habitus or caenotelic] is somewhat like the reading of a difficult palimpsest.

Broom and Gregory were well-acquainted with one another, and Broom visited the American Museum in 1913-1914, so the use of the term palimpsest by the two of them is probably not independent.

Not all historical processes leave clear traces of their paths: if a ball rolls downhill to a resting place, we cannot infer from where on the surrounding heights it began; and one molecule of water is just like another (of the same isotopes), no matter whence it came.  We are fortunate that descent with modification is a history-conserving process: bodies and genomes of organisms are documents of evolutionary history. As the many examples in WEIT show, even when a fossil record is lacking, we can learn much about an organism’s evolution.

Caturday cricetid

March 7, 2009 • 12:42 pm

by Greg Mayer

To give a little equal time to other trophic levels, this Saturday we have a meadow vole, a member of the rodent family Cricetidae.

Voley
Voley

Nicknamed ‘Voley’, this Microtus pennsylvanicus was rescued from a mechanical access shaft into which it had fallen and become trapped. What many people think of as ‘field mice’, and what many house cats bring home, are actually voles: they can be distinguished by their short tails, and smaller eyes and ears compared to other mice. Evolutionarily, meadow voles are known for being geographically variable, with many described subspecies, including a number restricted to small islands off the coast.  Since most of these islands are land-bridge islands, isolated from the mainland only since the post-glacial rise in sea level, the differentiation of the voles inhabiting them is quite recent. The most distinctive of these small island derivatives of the meadow vole is a distinct species, the beach vole, Microtus breweri, found only on Muskeget, a very small island to the west of Nantucket Island, Massachusetts. (My friend and colleague James ‘Skip’ Lazell calls it “defiantly” distinct from the meadow voles on nearby islands.) They have been isolated on Muskeget only 2000-3000 years, and are thus an example of rapid divergence. Jerry deals with  the nature of species and species formation in chap. 7 of WEIT, and in much more detail in his 2004 monograph with H. Allen Orr, Speciation.

Skell pwned again

March 5, 2009 • 12:13 pm

by Greg Mayer

I think I’ve been able to figure out why chemist Philip Skell’s attack on Jerry in Forbes was so unresponsive to what Jerry actually wrote: he probably wrote most of it before seeing Jerry’s article!  P.Z. Myers noted a piece in the Eugene, Oregon, Register-Guard by teacher Stuart Faulk rebutting Skell’s arguments.  Addressing Skell’s claim that evolution is irrelevant to medicine, Faulk (who is Skell’s son-in-law!) does some research:

The contention that evolutionary science is not useful is easily shown false by counter-example. The necessary research is accomplished by walking the five feet to my coffee table and picking up the March edition of Scientific American magazine, in which the article “New Tactics Against Tuberculosis” describes progress against the spread of drug-resistant TB….As the authors state of one promising approach, “It allows us to harness the power of natural selection in our quest to thwart (drug-resistant TB).”

He also notes that Skell’s claim that for evolution to be relevant  to medicine, then paleontology must drive its research agenda, is an “absurd idea”,  “introduced by Skell, not evolutionary scientists.” Faulk goes on to note that Skell’s real concerns are religious, not scientific, as “any Web search will show”.

That Skell’s arguments are easily rebutted is not surprising; what is surprising is that Faulk was responding to something Skell wrote in the Register-Guard that appeared February 12, the same day as Jerry’s piece in Forbes, and 11 days before Skell’s piece in Forbes.  The Register-Guard piece is only available on the web as an excerpt, but it seems to be much the same as what appeared in Forbes. You compare:

The Register-Guard, Feb. 12: “Darwin was great, but too often he’s oversold”

In 1942 Nobel Laureate Ernst Chain wrote explicitly that his discovery (with Florey and Fleming) of penicillin, and the development of bacterial resistance to that antibiotic, owed nothing to Darwin’s and Alfred Wallace’s evolutionary theories. The same can be said about a variety of other 20th century discoveries: that of the structure of the double helix; the characterization of the ribosome; the mapping of genomes; research on medications and drug reactions; improvements in food production and sanitation; and various new surgeries.

Forbes, Feb. 23, “The dangers of overselling evolution”

In 1942, Nobel Laureate Ernst Chain wrote that his discovery of penicillin (with Howard Florey and Alexander Fleming) and the development of bacterial resistance to that antibiotic owed nothing to Darwin’s and Alfred Russel Wallace’s evolutionary theories.

The same can be said about a variety of other 20th-century findings: the discovery of the structure of the double helix; the characterization of the ribosome; the mapping of genomes; research on medications and drug reactions; improvements in food production and sanitation; new surgeries; and other developments.

I can understand why Jerry found Skell’s Forbes piece off-point:

The curious thing is that Skell’s piece is not, as it pretends to be, a critique of what I said in Forbes, but merely a repetition of the argument, which he has been making for years, that evolution is of no practical use for humanity and of no use to experimental biology

The one thing I would add to these critiques of Skell is to point out his curious use of the phrase “experimental biology”, and his disdain for what he seems to consider unobservable or uncertain knowledge.  He seems to imply that chemistry and “experimental” biology, are good science, because they are observable; other sorts of biology (i.e. evolution), and (if the apparent criterion is to be applied uniformly), geology and astronomy are not, because we have not seen a live trilobite, or Gondwanaland, or a star moving along the main sequence.  Thus creationists seek not just to eliminate biology, but much of the rest of science as well. All knowledge in empirical science, including chemistry, is tentative; and the changes in the kinds of plants and animals you see as you travel up slope on a fossiliferous exposure are much more observable than any chemical bond.