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Darwin-L Message Log 28: 1–17 — December 1995
Academic Discussion on the History and Theory of the Historical Sciences
Darwin-L was an international discussion group on the history and theory of the historical sciences, active from 1993–1997. Darwin-L was established to promote the reintegration of a range of fields all of which are concerned with reconstructing the past from evidence in the present, and to encourage communication among scholars, scientists, and researchers in these fields. The group had more than 600 members from 35 countries, and produced a consistently high level of discussion over its several years of operation. Darwin-L was not restricted to evolutionary biology nor to the work of Charles Darwin, but instead addressed the entire range of historical sciences from an explicitly comparative perspective, including evolutionary biology, historical linguistics, textual transmission and stemmatics, historical geology, systematics and phylogeny, archeology, paleontology, cosmology, historical geography, historical anthropology, and related “palaetiological” fields.
This log contains public messages posted to the Darwin-L discussion group during December 1995. It has been lightly edited for format: message numbers have been added for ease of reference, message headers have been trimmed, some irregular lines have been reformatted, and error messages and personal messages accidentally posted to the group as a whole have been deleted. No genuine editorial changes have been made to the content of any of the posts. This log is provided for personal reference and research purposes only, and none of the material contained herein should be published or quoted without the permission of the original poster.
The master copy of this log is maintained in the Darwin-L Archives (rjohara.net/darwin) by Dr. Robert J. O’Hara. The Darwin-L Archives also contain additional information about the Darwin-L discussion group, the complete Today in the Historical Sciences calendar for every month of the year, a collection of recommended readings on the historical sciences, and an account of William Whewell’s concept of “palaetiology.”
---------------------------------------------- DARWIN-L MESSAGE LOG 28: 1-17 -- DECEMBER 1995 ---------------------------------------------- DARWIN-L A Network Discussion Group on the History and Theory of the Historical Sciences Darwin-L@ukanaix.cc.ukans.edu is an international network discussion group on the history and theory of the historical sciences. Darwin-L was established in September 1993 to promote the reintegration of a range of fields all of which are concerned with reconstructing the past from evidence in the present, and to encourage communication among academic professionals in these fields. Darwin-L is not restricted to evolutionary biology nor to the work of Charles Darwin but instead addresses the entire range of historical sciences from an interdisciplinary perspective, including evolutionary biology, historical linguistics, textual transmission and stemmatics, historical geology, systematics and phylogeny, archeology, paleontology, cosmology, historical anthropology, historical geography, and related "palaetiological" fields. This log contains public messages posted to Darwin-L during December 1995. It has been lightly edited for format: message numbers have been added for ease of reference, message headers have been trimmed, some irregular lines have been reformatted, and some administrative messages and personal messages posted to the group as a whole have been deleted. No genuine editorial changes have been made to the content of any of the posts. This log is provided for personal reference and research purposes only, and none of the material contained herein should be published or quoted without the permission of the original poster. The master copy of this log is maintained in the archives of Darwin-L by listserv@ukanaix.cc.ukans.edu, and is also available on the Darwin-L Web Server at http://rjohara.uncg.edu. For instructions on how to retrieve copies of this and other log files, and for additional information about Darwin-L, send the e-mail message INFO DARWIN-L to listserv@ukanaix.cc.ukans.edu, or connect to the Darwin-L Web Server. Darwin-L is administered by Robert J. O'Hara (darwin@iris.uncg.edu), Center for Critical Inquiry in the Liberal Arts and Department of Biology, University of North Carolina at Greensboro, Greensboro, North Carolina 27412 U.S.A., and it is supported by the Center for Critical Inquiry, University of North Carolina at Greensboro, and the Department of History and the Academic Computing Center, University of Kansas. _______________________________________________________________________________ <28:1>From DARWIN@iris.uncg.edu Fri Dec 1 00:22:50 1995 Date: Fri, 01 Dec 1995 01:22:41 -0400 (EDT) From: DARWIN@iris.uncg.edu Subject: List onwer's monthly greeting To: darwin-l@ukanaix.cc.ukans.edu Organization: University of NC at Greensboro Greetings to all Darwin-L subscribers. On the first of every month I send out a short note on the status of our group, along with a reminder of basic commands. For additional information about the group please visit the Darwin-L Web Server (http://rjohara.uncg.edu). Darwin-L is an international discussion group for professionals in the historical sciences. The group is not devoted to any particular discipline, such as evolutionary biology, but rather seeks to promote interdisciplinary comparisons across the entire range of "palaetiology". Darwin-L currently has more than 600 members from over 30 countries. Because Darwin-L does have a large membership and is sometimes a high-volume discussion group it is important for all participants to try to keep their postings as substantive as possible so that we can maintain a favorable "signal-to-noise" ratio. Personal messages should be sent by private e-mail rather than to the group as a whole. Subscribers who feel burdened from time to time by the volume of their Darwin-L mail may wish to take advantage of the digest option described below. Because different mail systems work differently, not all subscribers see the e-mail address of the original sender of each message in the message header (some people only see "Darwin-L" as the source). It is therefore very important to include your name and e-mail address at the end of every message you post so that everyone can identify you and reply privately if appropriate. Remember also that in most cases when you type "reply" in response to a message from Darwin-L your reply is sent to the group as a whole, rather than to the original sender. The following are the most frequently used listserv commands that Darwin-L members may wish to know. All of these commands should be sent as regular e-mail messages to the listserv address (listserv@ukanaix.cc.ukans.edu), not to the address of the group as a whole (Darwin-L@ukanaix.cc.ukans.edu). In each case leave the subject line of the message blank and include no extraneous text, as the command will be read and processed by the listserv program rather than by a person. To join the group send the message: SUBSCRIBE DARWIN-L Your Name For example: SUBSCRIBE DARWIN-L John Smith To cancel your subscription send the message: UNSUBSCRIBE DARWIN-L If you feel burdened by the volume of mail you receive from Darwin-L you may instruct the listserv program to deliver mail to you in digest format (one message per day consisting of the whole day's posts bundled together). To receive your mail in digest format send the message: SET DARWIN-L MAIL DIGEST To change your subscription from digest format back to one-at-a-time delivery send the message: SET DARWIN-L MAIL ACK To temporarily suspend mail delivery (when you go on vacation, for example) send the message: SET DARWIN-L MAIL POSTPONE To resume regular delivery send either the DIGEST or ACK messages above. For a comprehensive introduction to Darwin-L with notes on our scope and on network etiquette, and a summary of all available commands, send the message: INFO DARWIN-L To post a public message to the group as a whole simply send it as regular e-mail to the group's address (Darwin-L@ukanaix.cc.ukans.edu). I thank you all for your continuing interest in Darwin-L and in the interdisciplinary study of the historical sciences. Bob O'Hara, Darwin-L list owner Robert J. O'Hara (darwin@iris.uncg.edu) Center for Critical Inquiry in the Liberal Arts and Department of Biology 100 Foust Building, University of North Carolina at Greensboro Greensboro, North Carolina 27412 U.S.A. _______________________________________________________________________________ <28:2>From rroizen@ix.netcom.com Fri Dec 1 10:29:34 1995 Date: Fri, 1 Dec 1995 08:28:27 -0800 From: rroizen@ix.netcom.com (Ron Roizen ) Subject: Darwin Letter in Today's NY Times To: DARWIN-L@ukanaix.cc.ukans.edu Following letter appeared in the NY Times today (12/1/95, p. A14). The title line read: "What the Mockingbirds Taught Darwin." Incidentally, the letter is graced with a whimsical line drawing of a curious Darwin peering at a bird on flat ground through a monocle. Ron Roizen To the Editor: A Nov. 28 article on the Galapagos Islands summarizes the political crisis that has placed their ecological integrity at risk. The article, unfortunately, perpetuates myths about Darwin's experiences in Galapagos. Not only are there fewere than "39 kinds of finches" in the archipelago (thee are 13 species), but also Darwin observed only 6 species druning his brief stay (on four islands) in 1835 -- including 2 that he did not even recognize as finches! That the Galapagos finches were not critical in the development of "Origin of Species" is clear: Darwin did not mention these birds in the first edition, though he came to appreciate their relevance in later editions and in his published journal. In contrast, the island's native mockingbirds had a profound influence on Darwin's thinking. His realization that the three species he encountered differed among nearby islands represents the first and most significant step motivating Darwin to search for a cheanism capable of producing such differences. The finches exhibit a pattern of adaptive radiation (differentiation) consistent with Darwin's methanism (natural selection), but this conclusion came late to Darwin and was not fleshed out until this century in studies by biologists like David Lack, Robert Bowman and Peter and Rosemary Grant. Robert L. Curry Assistant Professor of Biology Villanova University Villanova, Pa., Nov. 28, 1995 _______________________________________________________________________________ <28:3>From g-cziko@uiuc.edu Sat Dec 2 21:59:11 1995 Date: Sat, 2 Dec 1995 21:59:22 -0600 To: darwin-l@ukanaix.cc.ukans.edu From: g-cziko@uiuc.edu (CZIKO Gary) Subject: Time Magazine on "Supersonic Evolution" [from Gary Cziko <g-cziko@uiuc.edu>] It's been mighty quiet on Darwin-L lately. So I suppose it's time to stir up some more trouble. Waiting in the supermarket checkout line, I couldn't resist picking up a copy of the December 4 Time Magazine when I saw on its cover in big yellow letters "EVOLUTION'S BIG BANG." I first thought that it must have been a slow week for big news stories. But then I realized that evolution IS news to most Americans. Here are some selected quotes from the magazine cover and cover story (with EMPHASES added): ********************************************************* "New discoveries show that life as we know it began in an amazing biological frenzy that changed the planet ALMOST OVERNIGHT." (front cover) "For billions of years, simple creatures like plankton, bacteria and algae ruled the earth. Then SUDDENLY, life got very complicated." (article lead-in, p. 67) " . . . creatures with teeth and tentacles and claws and jaws materialized WITH THE SUDDENNESS OF APPARITIONS." (p. 68) " . . . the period of biological innovation occurred AT VIRTUALLY THE SAME INSTANT in geologic time all around the world." (p. 68) "EVOLVING AT SUPERSONIC SPEED" (section title, p. 70) BEYOND DARWINISM (section title, p. 73) "'What Darwin described in the _Origin of Species_,' observes Queen's University paleontologist Narbonne, 'was the steady background kind of evolution. But there also seems to be a non-Darwinian kind of evolution that functions over extremely short time periods--and that's where all the action is.'" (p. 74) "'We now know how fast fast is,' grins [MIT's Samuel] Bowring. 'And what I like to ask my biologist friends is, How fast can evolution get before they start feeling uncomfortable?'" (p. 70) ********************************* Even though I am no biologist, I must admit that I am getting pretty uncomfortable, with terms like "almost overnight," "instant," "supersonic speed", and "suddenness of apparitions" being used to describe evolution. Darwin (and my universal selection theory) is in BIG TROUBLE if dramatic increases in adapted complexity evolved almost overnight at supersonic speed. I hope that some of the biologists on the list can clue me on how this can all happen so fast without miracles using "non-Darwinian evolution." If they can't, I suppose I will have to go back to my prior belief in a Grand Designer who takes it easy most of the time but who put in a hell of a lot of work one night about 500 million years ago. --Gary Cziko P.S. It's interesting that people like Dawkins and Maynard Smith and Dennett (OK, I realize that Dennett is just a philosopher) were not mentioned in the article, while Gould was. But that's probably because the former three keep harping on the old-fashioned Darwinian stuff which is not "where all the action is." P.P.S. There are some great illustrations in the article. The "burst of creativity" one on pages 70-71 is one of the best I've seen (despite it's name) for giving an overview of the time scale of life on earth. ------------------------------------------------------------------- Gary Cziko Associate Professor Telephone 217-333-8527 Educational Psychology FAX: 217-244-7620 University of Illinois E-mail: g-cziko@uiuc.edu 1310 S. Sixth Street Radio: N9MJZ 210 Education Building Champaign, Illinois 61820-6990 http://www.uiuc.edu/ph/www/g-cziko/ ------------------------------------------------------------------- _______________________________________________________________________________ <28:4>From Agoldenk@aol.com Sun Dec 3 11:12:07 1995 Date: Sun, 3 Dec 1995 12:12:03 -0500 From: Agoldenk@aol.com To: darwin-l@ukanaix.cc.ukans.edu Subject: Re: Time Magazine on "Supersonic Evolution" Well, an interesting article it was. . . Only Time, or some other popular journal concerned more with selling paper rather than accuracy, could confuse 20 to 30 million years with "overnight". There may be room for more than one bush or tree (see David Deamer's work on cell membrane formation happing in several places at once), but I read nothing that completely shakes the theory. Modifies, yes. The rate and units of selection are open issues as far as I'm concerned. _______________________________________________________________________________ <28:5>From elanier@crl.nmsu.edu Sun Dec 3 15:57:59 1995 Date: Sun, 3 Dec 1995 14:57:53 -0700 To: darwin-l@ukanaix.cc.ukans.edu From: elanier@crl.nmsu.edu (Ellery Lanier) Subject: supersonic speed We are all indebted to Gary for having made the evolutionary leap so easy for us. His listing of selected quotes finally bridges the gap between fine literature and fine science. I believe the Time copy people must take lessons from the Witnesses. Almost as much fun. ALMOST OVERNIGHT SUDDENLY WITH THE SUDDENNESS OF APPARITIONS AT VIRTUALLY THE SAME INSTANT EVOLVING AT SUPERSONIC SPEED BEYOND DARWINISM that's where all the action is. Such onomatopoeia! (spelling?) and I thought I understood Darwin! Give the Time writers a cigar. Thank you Gary, you made my sunday afternoon. ellery _______________________________________________________________________________ <28:6>From KOLB@ucla.edu Sun Dec 3 17:25:13 1995 Date: Sun, 3 Dec 1995 15:08:36 -0800 To: darwin-l@ukanaix.cc.ukans.edu From: Jack Kolb <KOLB@ucla.edu> Subject: Re: Time Magazine on "Supersonic Evolution" Gary's post provides me (a decided non-scientist: be gentle, please {grin}) with an opportunity to pose another potential topic of discussion: an article in the October issue of _Discover_ magazine about the theory of Hypersea (the biological linkage of life on earth [vs. life in the oceans]). I'll try to elaborate if anyone cares. I found it utterly fascinating, but obviously don't know enough to judge its soundness. Jack. kolb@ucla.edu _______________________________________________________________________________ <28:7>From BENEDICT@VAX.CS.HSCSYR.EDU Mon Dec 4 11:11:33 1995 Date: Mon, 04 Dec 1995 12:10:32 -0500 (EST) From: BENEDICT@VAX.CS.HSCSYR.EDU Subject: Re: Time Magazine on "Supersonic Evolution" To: darwin-l@ukanaix.cc.ukans.edu In defense of Time, you need to do a little math here. Life has been around for about 3X10^9 years and the period discussed is about 3X10^7 years long, so all this appears to have happened in about 1/100th of the period living things have been around. That sounds pretty "overnight" to me. On the other hand it took about 2.5X10^9 years to evolve the cellular and genetic machinery needed to permit this evolutionary explosion, and most of those changes didn't have a big effect on the outward appearance of living creatures until about 0.6X10^9 years ago. But remember, that's more than 80% of the time life has been around, and the number gets worse the older you assume that life first appeared, so maybe it isn't so amazing after all. But those were really great drawings... Paul DeBenedictis SUNY Health Science Center at Syracuse _______________________________________________________________________________ <28:8>From mwinsor@epas.utoronto.ca Mon Dec 4 10:47:41 1995 From: Mary P Winsor <mwinsor@epas.utoronto.ca> Subject: multiplying elephants To: darwin-l@ukanaix.cc.ukans.edu (bulletin board) Date: Mon, 4 Dec 1995 11:47:15 -0500 (EST) I am using John Moore's <Science as a Way of Knowing: the Foundations of Modern Biology> (Harvard U.P. 1993) for an undergraduate course, and I often find myself writing little notes to my students, quarreling with him. For example, on p. 161-2, Moore quotes Darwin's "There is no exception to the rule that every organic being naturally increases at so high a rate, that if not destroyed, the earth would soon be covered by the progeny of a single pair." Assuming a pair of elephants brings forth 6 young, Darwin calculates that "at the end of the fifth century there would be alive fifteen million elephants, desended from the first pair." Moore then says, "Yet in all likelihood, an average original pair would have only two surviving offspring - 14,999,998 would have perished. The struggle for existence is a tremendously impressive fact of nature." To this I reply, Moore is quite wrong to conclude that Darwin's application of Malthusian reasoning tells us that 14,999,998 elephants must perish in the five centuries of Darwin's thought experiment. The point for both Malthus and Darwin is the contrast between a calculated geometric population growth that could theoretically occur on the one hand, and on the other hand the roughly constant levels at which populations actually maintain themselves. Potential for geometric increase does not require a high rate of fertility, but is present for any organism whose lifetime fertility is greater than one. Darwin imagines an elephant having only 6 baby elephants in all her 60 fertile years, and he calculates that in less than 500 years (in fact, in 14 generations) her offspring will number 15 million. In this thought experiment, no young elephants ever perish; all elephants grow to adulthood, raise offspring, and die of old age. If now we wish to switch to a more realistic scenario, where a pair of elephants leaves only two surviving offspring, we must admit that somehow the four other babies perished. Continuing the thought experiment, where the population is not growing, we can tally four perishing young elephants per mother in each generation. Over the 14 generations of Darwin's experiment, that is only 56 superfluous offspring. The millions of the first thought experiment never come into existence in the second, more realistic, thought experiment. The Malthusian principle of population pressure does not wait lurking, only to take effect by killing off superfluous elephants at the end. It operates all the time, preventing the potential increase from occuring. It is also misleading for Moore to say "in all likelihood, an average original pair would have only two surviving offspring" [after the 14 generations]. By definition, a statistically typical mother of the first generation would have left in the final generation one many-greats-grand- daughter, but here is where statistics are misleading. They key to Darwin's theory lies in the fact that "in all likelihood," some of the original elephants could have left many more than their share of descendants after 14 generations, indeed one elephant could have generated millions, while other elephants experienced the dark side of the law of averages, and will have left no descendant at all. In all likelihood, the average is not typical. Polly Winsor mwinsor@epas.utoronto.ca P.S. Bob O'Hara points out to me that one of Darwin's readers in 1869 recognized there were some problems with exactly how many elephants would be alive after exactly how many centuries, and Darwin agreed, but the precise number is not relevant to the point I make here. (Darwin Origin of Species, facsimile p. 64; Collected Papers of CD ed. Paul H. Barrett, pp.156-7) _______________________________________________________________________________ <28:9>From ahouse@hydra.rose.brandeis.edu Tue Dec 5 09:42:04 1995 Date: Tue, 5 Dec 1995 10:41:57 -0500 To: Darwin-L@ukanaix.cc.ukans.edu (Darwin List) From: ahouse@hydra.rose.brandeis.edu (Jeremy C. Ahouse) Subject: Darwin: the last(?) portrait FYI: a newly discovered portrait of Charles Darwin: Milner, Richard (1995) "Charles Darwin: the Last Portrait" Scientific American. November, pg 78-79. _______________________________________________________________________________ <28:10>From ahouse@hydra.rose.brandeis.edu Tue Dec 5 09:51:39 1995 Date: Tue, 5 Dec 1995 10:51:35 -0500 To: Darwin-L@ukanaix.cc.ukans.edu (Darwin List) From: ahouse@hydra.rose.brandeis.edu (Jeremy C. Ahouse) Subject: Re: Time Magazine If you are interested in reading the actual article from Time Nash, J. Madeleine (1995) "When Life Exploded" Time. v146 n23. 4 December p66-74 is available on the web: http://pathfinder.com/@@xVbMYcGrwAAAQDZi/time/magazine/ domestic/1995/951204/cover.html - Jeremy Jeremy C. Ahouse Biology Department Brandeis University Waltham, MA 02254-9110 ph: (617) 736-4954 fax: (617) 736-2405 email: ahouse@hydra.rose.brandeis.edu "I am a carnivorous fish swimming in two waters, the cold water of art and the hot water of science." -Salvador Dali _______________________________________________________________________________ <28:11>From charlie_urbanowicz@macgate.csuchico.edu Tue Dec 5 12:18:55 1995 Date: 5 Dec 1995 10:13:57 U From: "Charlie Urbanowicz" <charlie_urbanowicz@macgate.csuchico.edu> Subject: TIME MAGAZINE To: darwin-l@ukanaix.cc.ukans.edu Many probably already know this, but just in case: the text of the TIME article is available from TIME @ http://pathfinder.com/@@945*k1HllQAAQEhi/time/magazine/domestic/1995 /951204/cover.html BUT, you might wish to start @ the TIME-WARNER Home Page: http://pathfinder.com [and actually go to http://pathfinder.com/@@*3nPDHGVkgAAQEli/time/universe.html for "Back Issues" of TIME. Charlie Urbanowicz [curbanowicz@oavax.csuchico.edu] _______________________________________________________________________________ <28:12>From hurd@bethel.edu Tue Dec 5 13:36:09 1995 Date: Tue, 5 Dec 95 14:54:31 CST From: "James Hurd" <hurd@bethel.edu> To: darwin-l@ukanaix.cc.ukans.edu Subject: Re: New book on evolutionary biology Introducing a new book: INVESTIGATING THE BIOLOGICAL FOUNDATIONS OF HUMAN MORALITY: An Interdisciplinary Perspective. Edited by James P. Hurd The central question of this volume is: To what extent is evolutionary biology a necessary and sufficient explanation for human morality? Biologists, psychologists, anthropologists, theologians, and philosophers address this question from their respective disciplines. Four main issues are addressed: -- Is human moral behavior unique? To what extent can it be explained using models of animal behavior? -- Does biology provide us only with a DEscription of how morality has evolved or can it also provide us with a PREscription for what morality should be? If the latter, do we seek to prescribe moral behavior as that behavior which our biology has programmed, or is morality a culturally- designed resistance to our biological propensities? -- Can morality be adequately explained by a demonstration of natural selection operating at the individual level, or are we forced to consider natural selection operating at the level of the group or species? -- To what extent can humans make autonomous moral choices (i.e., choices not predetermined by biology or environment)? This volume will interest scholars, students, and academic libraries in the areas of sociobiology, ethics, religion, and social philosophy. It will serve as a text for courses in ethics or sociobiology at the graduate level and as a supplementary text for courses in ethics, philosophy, psychology or anthropology at the undergraduate level. Available from: Edwin Mellen Press, P.O. Box 450; Lewiston, New York 14092. Telephone: 716 754-2266. ISBN: 0-7734-8843-x 264 pp. Textbook price: $29.95 (five or more copies). _______________________________________________________________________________ <28:13>From ahouse@hydra.rose.brandeis.edu Wed Dec 6 07:50:37 1995 Date: Wed, 6 Dec 1995 08:50:33 -0500 To: Darwin-L@ukanaix.cc.ukans.edu (Darwin List) From: ahouse@hydra.rose.brandeis.edu (Jeremy C. Ahouse) Subject: Kanzi: The Ape There is a Review of Savage-Rumbaugh and Lewin's "Kanzi: The Ape ..." by John Mitani from SCIENTIFIC AMERICAN, June 1995, Volume 272 Number 6 available on the web http://envirolink.org/arrs/essays/kanzi_review.html - Jeremy Jeremy C. Ahouse Biology Department Brandeis University Waltham, MA 02254-9110 ph: (617) 736-4954 fax: (617) 736-2405 email: ahouse@hydra.rose.brandeis.edu "I am a carnivorous fish swimming in two waters, the cold water of art and the hot water of science." -Salvador Dali _______________________________________________________________________________ <28:14>From g-cziko@uiuc.edu Wed Dec 6 09:05:39 1995 Date: Wed, 6 Dec 1995 09:06:37 -0600 To: darwin-l@ukanaix.cc.ukans.edu From: g-cziko@uiuc.edu (CZIKO Gary) Subject: Fast Evolution: Do We Need a Miracle? [from Gary Cziko <g-cziko@uiuc.edu> Thanks to Charlie Urbanowicz and Jeremy Ahouse for pointing out how to get the TIME article on evolution on the web. This makes it much easier to refer to. Here is the part I find particularly interesting: """"""""""""""""""""""""""""""""""""""""""""""""""""" EVOLVING AT SUPERSONIC SPEED Scientists used to think that the evolution of phyla took place over a period of 75 million years, and even that seemed impossibly short. Then two years ago, a group of researchers led by Grotzinger, Samuel Bowring from M.I.T. and Harvard's Knoll took this long-standing problem and escalated it into a crisis. First they recalibrated the geological clock, chopping the Cambrian period to about half its former length. Then they announced that the interval of major evolutionary innovation did not span the entire 30 million years, but rather was concentrated in the first third. "Fast," Harvard's Gould observes, "is now a lot faster than we thought, and that's extraordinarily interesting." """"""""""""""""""""""""""""""""""""""""""""""""""""" So if the initial of estimate of 75 million years is "impossibly short" for the evolution of phyla, then the current estimate of 10 million must be downright miraculous. But is it? 10 million still seems like a very long time to me, but then again I am still rather young (as least by these standards). If we went back to the Cambrian in a time machine to observe what was going on, would we even notice anything happening during this "explosion" of life? What would be the generational time of these organisms that were evolving into different phyla? How many generations would there be in just 10 million years? I hope that some biologists can answer these questions. It would be wonderful if this time span really was impossibly short for the phyla to evolve using old-fashioned stupid, slow and gradual Darwinian selection, since then I would finally be able to reject universal selection theory for something better. Perhaps miracles is "where the action is" after all. --Gary Cziko ------------------------------------------------------------------- Gary Cziko Associate Professor Telephone 217-333-8527 Educational Psychology FAX: 217-244-7620 University of Illinois E-mail: g-cziko@uiuc.edu 1310 S. Sixth Street Radio: N9MJZ 210 Education Building Champaign, Illinois 61820-6990 http://www.uiuc.edu/ph/www/g-cziko/ ------------------------------------------------------------------- _______________________________________________________________________________ <28:15>From ncse@crl.com Wed Dec 6 17:11:51 1995 Date: Wed, 6 Dec 1995 14:56:20 -0800 (PST) From: "Eugenie C. Scott" <ncse@crl.com> To: darwin-l@ukanaix.cc.ukans.edu Subject: Re: New book on evolutionary biology Another book on the same topic is *Created from Animals, the Moral Implications of Darwinism* by philosopher James Rachels. ECS _______________________________________________________________________________ <28:16>From ahouse@hydra.rose.brandeis.edu Thu Dec 7 10:34:01 1995 Date: Thu, 7 Dec 1995 11:33:56 -0500 To: Darwin-L@ukanaix.cc.ukans.edu (Darwin List) From: ahouse@hydra.rose.brandeis.edu (Jeremy C. Ahouse) Subject: Dennett Ch.10 review (2/2) It trivializes the breadth of Gould's Burgess Shale book to focus on two conclusions. But let's push ahead with Dennett as he focuses on contingency and disparity. Contingency he takes as obvious and not worth raising... implying that Gould is trading in trivialities. You will have to decide if Gould's compilation of progressivist human (male) centric iconography justifies making this point to the audience that would be interested in this book. The second question is; how do we measure and assess the direction of morphological change through time? And when we unpack this; what are the dynamics of variation in the lineages in the tree of life? Mark Ridley in his review complained that Gould has energized this argument with a mistaken criterion; the use of higher taxonomic categories (Ridley 1990). I agree with the point that Ridley has to make. This problem in systematics (what, if anything do grade based higher level taxa mean) is still open. Gould claims to have other criteria (Gould 1991) including raising points about cladograms that use a large number of loss-of-feature character state transitions. In doing so he implicitly raises the thorny issue of character weighting in a cladistic framework. Both sides of this debate are worth spending time with (Gould 1993; McShea 1993; Ridley 1993). Get yourself a copy of the wonderful coffee table book on the Burgess (just out in paper Briggs, Erwin et al. 1994) and see how you would classify this fauna. Dennett does not address this important issue. He does however hammer away at contingency (which, remember, he thinks is a trivial point); "evolution can be an algorithm, and evolution can have produced us by an algorithmic process, without it being true that evolution is an algorithm for producing us" (pg. 308 Dennett 1995). If you are attracted to his use of the word algorithm to mean process then once again he is falling into line with Gould although you wouldn't sense that from the tone. I think it falls to Dennett to show that the lay audience for Gould's books have all long ago rejected any teleological leanings and so don't need to be reminded that humans are not the point of the narrative... even more challenging is that there is no narrative in the traditional sense. This is what Gould, who knows how to tell a good story, must grapple with. How do you deliver in an engaging way the message that there is no simple narrative, no simple moral to be drawn from the history of life? Ironically Gould and Dennett share the desire to remove the comfort of the idea that the world exists solely for us and that humans are the inevitable result of evolution. Though (contra Gould) Dennett may be arguing that some kind of sentience is inevitable. In making the case against teleology Gould insinuates these ideas more gently, without insisting that his religious colleagues are lazy and dishonest; compare "those evolutionists who see no conflict between evolution and their religious beliefs have been careful not to look as closely as we have been looking, or else hold a religious view that gives God what might we call a merely ceremonial role to play" (pg. 310 Dennett 1995). The symbolic and mystical traditions that humans use to find personal (and importantly, social) identity and meaning shouldn't be so summarily dismissed. It is important to recognize that some of Gould's distinctions were intended as therapeutic, designed to pull people from careless habits. Dennett in firm possession of a pristine adaptationism (8) would not formally make any of these mistakes and so may not need the correctives. But he has yet to demonstrate that the larger population of biologists (or Gould's lay audience) had nothing to gain from spandrels, stasis, or contingency. What drives Dennett's narrative? One possibility was offered to me at a seminar. I wondered aloud who this book was for. A computer scientist suggested that maybe it was for the Alife crowd. They enjoy the assumption that the "evolution" that is seen in simulations is deeply representative of what has happened on this planet. This position is much easier to sustain if you strip all the bothersome (intricate) details out of the biological picture and synonymize evolution with a simple selectionism. Mark Ridley's review of "Darwin's Dangerous Idea" (Ridley 1995) makes the point that while "natural selection arguably is the universal explanation for biological adaptation, it is not for evolution." This raises the possibility that Dennett is really more of a Spencerian, enthusiastic about selectionist models and ready to use them whenever and wherever he can? While I share his enthusiasm for the wonderful possibilities that natural selection suggests, the strident and self righteous tone of "Dangerous Idea" will leave this book only the audience of the converted, and they would probably prefer something more nuanced and careful (e.g. Keller and Lloyd 1992; Sober 1994). I don't want to blunt Dennett's enthusiasm for evolutionary biology - champions are to be prized. Though I fear that his enthusiasm is for selectionist theories not for explaining the distribution and abundance of living forms, and this induces him to walk in with a bit too much baggage, he "knows" too much. "The action of thought is excited by the initiation of doubt, and ceases when belief is attained..." (Peirce 1932). Maybe we can make a place safe enough for him to put some of those bags down and luxuriate in the intricacies of the biological world and let a little doubt shine in. ____ Thank you to the list for all the encouragement, please comment heartily. Thank you also to Ron Amundson, Hugh Pendleton, Craig Story, Gary Cziko, and John Barthel for various levels of comment and sparring. ____ (1) It remains a possibility that 'space' (design or morpho) is just Dennett's way of discussing a point set and that there is no need to have any sense of distance (a metric). I think that this move looses an interesting and important intuition. (2) Genetic algorithms (a current vogue in computer science) are used "experimentally" not analytically to solve particular problems. This area is full of questions about how a problem is to be encoded and how the solution landscape is related to the "genetic" operators that are used in the simulation. To get a sense of what is currently happening in the alife community visit http://www.krl.caltech.edu/~brown/alife/, http://alife.santafe.edu:80/~joke/zooland/, or http://alife.santafe.edu:80/alife/. It has been suggested to me that I am not charitable enough to a possible metaphorical reading of algorithm (i.e. that Dennett's use of algorithm is looser and does not entail all that it would technically entail). I will resist granting this (unless Dennett expressly asks for this kind of release) because he seems to trade on our enthusiasm for guaranteed results from algorithms to say that Natural Selection carries a guarantee. (3) "At the beginning you achieve success if you are interesting to a growing audience. If nonexperts at your game begin to use it metaphorically, leading to other interesting conversations, you have success-two. If you get beyond this stage, make a research project out of determining criteria for success." (Pendleton 1995) (4) While there are certainly still creationists in American society and there are many people who know very little about the distribution and abundance of living forms and so don't feel that they need a theory of evolution to explain the world that they see around themselves. But Dennett isn't weighing in on that debate. Is Dennett claiming that Gould's discussion of the adaptationist program, punctuated equilibrium, the Burgess Shale, etc... is a critical part of the armamentarium of creationists? (5) Studying proteins is a dizzying exercise in the complexities of function assignment. This is readily seen after a particular function has been identified (e.g. the fibroblast growth factor receptor) and then it turns out that you can find that molecule interacting with other things than you had imagined when it was named (e.g. novel ligands for the FGF receptor Kinoshita, Minshull et al. 1995). (6) The paralogy and orthology distinction was introduced 25 years ago to distinguish two kinds of homology in proteins (Fitch 1970). While orthology has the traditional meaning of morphological homology, paralogy is meant to cover those situations when a gene duplication allows related proteins to evolve independently within the same linneage. Orthologs are found in different individuals and paralogs can be found in the same individual. These and other important issues in protein evolution are reviewed in the introduction to the proceedings of the Third International Congress of Systematics and Evolutionary Biology (Patterson 1987). (7) You can find a review of punk eek (Prothero 1992) on the net; http://www.skeptic.com/01.3.prothero-punc-eq.html. (8) As I read Dennett I get the sense that he believes that biologists long for a kind of crystal palace of perfect adaptationism. In a previous post I referred to this palace as vapid selectionism. I meant that rather literally. My American Heritage dictionary offers; lacking taste, zest, flavor: vapid beer. This is what I wanted to capture. The biologists I know glory in the exquisite mix of contingency, adaptation and constraint that is in evidence in the uncountable compromises that result in a particular ecosystem on a particular day resulting in (to emphasize the contrast) an epicurean selectionism. ____ Adams, D. (1988). The Long Dark Tea-Time of the Soul. New York, Simon and Schuster. Ahouse, J. J., J. Hagerman, et al. (1993). "Mouse MHC Class I-like Fc Receptor Encoded Outside the MHC." Journal of Immunology 151(11): 6076-6088. Briggs, D. E. G., D. H. Erwin, et al. (1994). The Fossils of the Burgess Shale. Washington, Smithsonian Institution Press. Burmeister, W. P., A. H. Huber, et al. (1994). "Crystal structure of the complex of rat neonatal Fc receptor with Fc." Nature 372: 379-383. Carroll, S. B., S. D. Weatherbee, et al. (1995). "Homeotic genes and the regulation and evolution of insect wing number." Nature 375: 58-61. Cormen, T. H., C. E. Leiserson, et al. (1990). Introduction to Algorithms. Cambridge, MA, MIT Press. Day, S. (1995). "Invasion of the shapechangers." New Scientist 28 October: 30-35. Dennett, D. (1993). "Confusion over evolution: an exchange." New York Review of Books 14 January: 43-44. Dennett, D. C. (1995). Darwin's dangerous idea: evolution and the meanings of life. New York, Simon & Schuster. Fitch, W. M. (1970). "Distinguishing homologous from analogous proteins." Systematic Zoology 19: 99-113. Fleagle, J. G. (1988). Primate adaptation and evolution, Academic Press. Fontana, W., G. Wagner, et al. (1994). "Beyond Digital Naturalism." Artificial Life 1: 211-227. Gottlieb, A. (1995). "We are all cousins: Darwin's Dangerous Idea." The Spectator 275(8724) 23 September: 34-36. Gould, S. J. (1977). Darwin's Untimely Burial. Ever Since Darwin. NY, Norton. Gould, S. J. (1989). Wonderful Life: The Burgess Shale and the Nature of History. NY, W. W. Norton & Co. Gould, S. J. (1991). "The disparity of the Burgess Shale arthropod fauna and the limists of cladistic analysis: why we must strive to quantify morphospace." Paleobiology 17(4): 411-423. Gould, S. J. (1992). "The confusion over evolution." New York Review of Books 19 November: 47-54. Gould, S. J. (1993). "Confusion over evolution: an exchange." New York Review of Books 14 January: 44. Gould, S. J. (1993). "How to analyze the Burgess Shale disparity - a reply to Ridley." Paleobiology 19(4): 522-523. Gould, S. J. (1994). "Common Pathways of Illumination: Humans and squid may literally look at things the same way." Natural History(December): 10-20. Gould, S. J. (1994). "Tempo and mode in macroevolutionary reconstruction of Darwinism." PNAS 91: 6764-6771. Gould, S. J. and N. Eldredge (1993). "Punctuated Equilibrium comes of age." Nature 366: 223-227. Gould, S. J. and R. C. Lewontin (1979). "The spandrels of San Marco and the Panglossian Paradigm: a critique of the adaptationist programme." Proceedings of the Royal Society of London B 205: 581-598. Gould, S. J. and E. S. Vrba (1982). "Exaptation - a missing term in the science of form." Paleobiology 8: 4-15. Gray, R. (1992). Death of the Gene: Developmental Systems Strike Back. Trees of Life. P. Griffiths. Netherlands, Kluwer Academic: 165-209. Halder, G., P. Callaerts, et al. (1995). "New perspectives on eye evolution." Current opinion in Genetics & Development 5: 602-609. Holt, J. (1995). "Bookshelf: Wholly DNA: Defending natural selection." The Wall Street Journal 4 August: 6 (sec. A). Kandil, E., M. Noguchi, et al. (1995). "Structural and Phylogenetic Analysis of the MHC Class I-Like Fc Receptor Gene." Journal of Immunology 154: 5907-5918. Keller, E. F. and E. A. Lloyd, Eds. (1992). Keywords in Evolutionary Biology. Cambridge, MA, Harvard University Press. Kinoshita, N., J. Minshull, et al. (1995). "The Identification of Two Novel Ligands of the FGF Receptor by a Yeast Screening Method and Their Activity in XenopusDevelopment." Cell 83(17): 621-630. Lewin, R. (1995). "Disrobing the Naked Ape." Los Angeles Times 14 May: 3 (sec BR). Lufkin, T., M. Mark, et al. (1992). "A Homeotic Transformation of the Occipital Bones of the skull by ectopic expression of a homeobox gene." Nature 359(6398): 835-841. Masters, J. (1995). "The Rules of the Game." Book World 16 July: 8. Maynard-Smith, J. (1995). "Genes, Memes, & Minds." New York Review of Books 30 November: 46-48. McShea, D. W. (1993). "Arguments, tests, and the Burgess Shale - a commentary on the debate." Paleobiology 19(4): 399-402. Murphy, E. A. (1979). "Quantitative Genetics: A Critique." Social Biology 26(2): 126-141. Nijhout, H. F. (1990). "Metaphors and the role of genes in development." Bioessays 12: 441-446. Papineau, D. (1995). "Natural Selections." The New York Times Book Review 14 May: 13 (sec 7). Patterson, C. (1987). Introduction. Molecules and morphology in evolution: conflict or compromise? C. Patterson. Cambridge, Cambridge University Press. Peirce, C. S. (1932). Collected Papers. Cambridge, MA, Harvard University Press: 2.113. Pendleton, H. (1995). personal communication. Pollock, R. A., S. Tadru, et al. (1995). "Gain of function mutations for paralogous Hox genes: Implications for the evolution of Hox gene function." Proceedings of the National Academy of Sciences of the United States of America 92: 4492-4496. Prothero, D. R. (1992). "Punctuated Equilibrium at Twenty: a Paleontological Perspective." Skeptic 1(3): 38-47. Quiring, R., U. Walldorf, et al. (1994). "Homology of the Eyeless gene of Drosophila to the Small Eye Gene in Mice and Aniridia in Humans." Science 265(5173): 785-789. Raup, D. and J. J. Sepkoski (1982). "Mass Extinction in the Marine Fossil Record." Science 215(19 March): 1501-1503. Ray, T. S. (1994). "An Evolutionary Approach to Synthetic Biology: Zen and the Art of Creating Life." Artificial Life 1: 179-209. Ridley, M. (1990). "Dreadful Beasts: a review of Wonderful Life by Stephen Jay Gould." The London Review of Books(28 June): 11-12. Ridley, M. (1993). "Analysis of the Burgess Shale." Paleobiology 19(4): 519-521. Ridley, M. (1995). "Here, there, everywhere." Nature 375(6531): 457-458. Rorty, R. (1995). "Cranes and Skyhooks." Lingua Franca(July/August) : 62-65. Salvini-Plawen, L. and E. Mayr (1977). "On the evolution of photoreceptors and eyes." Evolutionary Biology 10: 207-263. Sober, E., Ed. (1994). Conceptual Issues in Evolutionary Biology. Cambridge, MA, MIT Press. Weigel, D. and E. M. Meyerowitz (1994). "The ABCs of Floral Homeotic Genes." Cell 78: 203-209. _______________________________________________________________________________ <28:17>From ahouse@hydra.rose.brandeis.edu Thu Dec 7 10:33:11 1995 Date: Thu, 7 Dec 1995 11:32:57 -0500 To: Darwin-L@ukanaix.cc.ukans.edu (Darwin List) From: ahouse@hydra.rose.brandeis.edu (Jeremy C. Ahouse) Subject: Dennett Ch.10 review (1/2) "For about a minute Dirk remained sitting motionless in his car a few yards away from his front door. He wondered what his next move should be. A small, cautious one, he rather thought. The last thing he wanted to have to contend with at the moment was a startled eagle." (pg. 211 Adams 1988) Over the last couple of months there has been some discussion of Daniel Dennett's characterization of Stephen Jay Gould as someone longing for miraculous explanations, out of touch with Darwinian explanations, and trying to push a political not a scientific agenda (ch. 10 Dennett 1995). These conclusions were clearly chosen for their rhetorical punch and by themselves might be enough to dismiss Dennett's project. I have said as much on this list and have tracked the reviews of Dennett's book waiting for someone to resist his contentious style and empirically unencumbered arguments. I recently listed all of the reviews I had uncovered (Gottlieb 1995; Holt 1995; Lewin 1995; Masters 1995; Maynard-Smith 1995; Papineau 1995; Ridley 1995; Rorty 1995), along with an anti-Gould sentiment from John Maynard-Smith's review. My comments at this point provoked Dennett. He wrote to me and asked that rather than "badmouthing" his efforts I should "try to show, in some detailed way, where my [his] analysis is unfair, mistaken, or even misleading." This note to Darwin-List is an explicit attempt to do what he requests. I hope that having flushed him out once, he will embrace the debate and we will hear more from him. Any of you who wish to return to the earlier discussions will find the Darwin-L logs archived at http://rjohara.uncg.edu/darwin/logs/. Dennett's position regarding Gould is curious. His disdain and dismissal of Gould is tied not to the work itself (in Dennett's estimation "a mild corrective to orthodoxy at best" (pg. 263 Dennett 1995)) but to the control that Gould seems to exert over Dennett's critics. These foes have rejected or resisted Dennett's work and rubbed his face in the claim that 'Gould has shown that Darwinism is a crock' and so any appeals to Darwinism are hopeless. If Dennett's arguments are not evaluated on their own merits by his colleagues and he sees Gould as the patron saint of those who would deny him, then we can understand his desire to bring Gould down. But I want to distinguish the belief that Darwinism has been gutted of explanatory force (what Dennett views as the "Gould-myth") from what Gould has actually done or attempted. I will be criticizing Dennett's misunderstanding of theories he ascribes to Gould and not second guessing the motives of Dennett's critics. This may already put us at cross-purposes. I find it odd to be an apologist for Gould, he can certainly fend for himself. I will not try to simulate him for the Darwin-L. My lack of appreciation for baseball (sorry, I am a basketball fan) rules me right out of contention as Gould's understudy. I will try to comment as we go along when I differ with positions Gould has articulated. If I have a position on the topic of the current state of evolutionary theory, it is that evolutionary biology is many leveled, complicated, and is carried on an ever shifting and expanding empirical base that when not attended to results in caricature. We can see one example of this caricature in Dennett's book. ____ I will begin by looking at some terminology that Dennett introduces early in the book, then move through the various arguments that Dennett touches on in the Gould chapter, and finish by speculating on who the audience for this book is and what may motivate Dennett's position. Dennett makes a distinction between skyhooks and cranes. Just so that you don't forget; skyhooks = miracles = bad and cranes = Darwinism = good. This analogy is supposed to help us make some of the distinctions that were traditionally captured in the struggle about teleology and to reemphasize that evolution must constantly work with what it currently has; cranes can be used to build bigger cranes but you can't hope for ropes to hang from the sky. Though Dennett is quite proud of the crane analogy it has the unfortunate feature of inviting lay readers to imagine a crane driver. We should be cautious about a metaphor that invites such goal directedness. It is ironic that someone who claims to have no allegiance to externalist teleology should deploy metaphors of skyhooks and cranes (What are they building? Who is driving?). I am certain that Dennett would reject this reading of his image, but I want to offer my reservations about the metaphor. Dennett sees evolution as a process of exploring "design space" an abstract (possibly platonic) multidimensional space that has designs in it. I will prefer 'morphospace' leaving designs and all of the functionalism that they imply as hypotheses that should be deployed critically (this is, after all, the point of the Spandrels paper (Gould and Lewontin 1979), see below). You can imagine an individual organism moving on a trajectory through morphospace during development. A population is a cloud in morphospace, when we add development the cloud gets bigger. Design space sounds so end-directed and final. Concentrating on a design space takes for granted part of what selectionist theories are meant to explain. If everything selected is "designed" and selection is then used to explain design we have the kind of trivial conclusion that we depend on philosophers to save us from. A change to 'morphospace' takes some of the shine off the skyhook/crane analogy but redirects us to a more important question; what variation is there for selection to act on. Universal selectionist are not usually making claims about the distribution of variation. But their (appropriate) emphasis on precisely that variation that is available to selection in a local population (a charitable reading of the admonition - "no skyhooks") can give the impression that they imagine some kind of normally distributed variance over all morphological variables. The traditional picture of bell curves with selection acting to shift the population mean reinforces this notion. But as is generally acknowledged the neighborhood in morphospace that is actually explored by a given population is due to a complicated mix of mutations, translocations, inversions and other genetic events that have anything but uniform effects on morphology as they affect different regulatory and structural genes (a dichotomy that sounds more absolute than it is (compare Nijhout 1990)). These, in turn, participate in developmental systems that facilitate and resist changes in morphospace and are have norms of reaction that can result in very different morphologies in different environmental contexts (another dichotomy, environmental/physiological, that implies a divide that isn't easy to sustain on close examination (this is a large literature, but see Gray 1992)). Given this, what is the variance for each trait? This is a major project in quantitative genetics (a good introductory discussion is Murphy 1979), and no amount of armchair biology will stand in for it. The design-space that Dennett asks us to imagine arises from hypotheses that are made about structures (and behaviors - much of the preceding paragraph can be applied to an abstract behavioral space). The core problem of something like a design space is that the appeal of a 'space' metaphor comes from the sense that there is a meaningful way to unpack the intuition of distance. A space has some kind of metric that lets me say A is closer to B than it is to C. If we don't really know what designs are close to others or if we are continuously surprised by how accessible one design is to another then our space will have an unusable metric and we will prefer to make an exhaustive list (1). Dennett's self claimed contribution to evolutionary theory is that natural selection is an algorithm. I have sympathies with the attempt to view biological processes computationally. But he manages to dilute the term so much that in his own estimation, "... are there any limits at all on what may be considered an algorithmic process? I guess the answer is No; if you wanted to, you could treat any process at the abstract level as an algorithmic process" (pg. 59 Dennett 1995). So he gets marks for honesty. At the same time, he misses a crucial part of thinking about algorithms; the importance of "data structures" - what is the universe over which an algorithm works. What bridge principles allow me to add 1 apple to 1 apple and get 2 apples while adding 1 sand pile to 1 sand pile can result in 1 sand pile? Dennett wants this algorithmic conception to lend an aura of guaranteed results to selectionism. Not so fast. There do exist algorithms that have provably guaranteed results; some examples can be found in any introductory text (Cormen, Leiserson et al. 1990). It isn't clear what is guaranteed by a selectionist algorithm (2) if we don't include a lot of information about what kind of variance is possible and what the basis of selection is. As artificial life models become more elaborate it may be that we will get a sense of both what is guaranteed and over what kinds of data types selectionist algorithms illustrate those guarantees (Fontana, Wagner et al. 1994). There has a been rush to embrace computer models as an alternate laboratory for evolutionary questions (an interesting laboratory is described in Ray 1994). It is important not to assume that we have reached this goal, as the journey has just begun. Dennett has an opportunity to discuss these issues at length after he introduces Conway's "Life" game and though he acknowledges the skyhook nature of the rules that govern this game, I really hoped for a more intense light to be shown on the question of what the patterns perceived by Dennett as he watches the rules being iterated mean. He talks about 'gliders' being annihilated by 'eaters' - but what do we learn about the kind of referent Dennett believes a model should have from this willingness to trade in very abstract entities. What should alife models be modeling? (There is a wonderful discussion to be had on this topic.) How do you measure success (3)? Understanding what kind of variation is possible and at what level selection occurs over those variations are what has driven the conversation about evolutionary biology at least since Darwin. In his narrative, Dennett gets the story of evolutionary biology all wrong. He places his emphasis on a divide between evil skyhook believers and righteous crane trusters. This kind of divide was current in the 1860's (my historian friends tell me that it was overblown even then. Did Darwin really, single handedly refute the Genesis creationists?) not in the 1960's or 1990's (4). The discussion in evolutionary biology is actually (to use Dennett-speak) how are the "cranes" made (in detail!) and what is the accessible neighborhood from a particular point in morphospace. In these debates Gould and others have weighed in. I entered Dennett's book via the chapter on Gould. I was trying to understand Dennett's manic attack (Dennett 1993) on Gould's review of Cronin's book in the NYR (Gould 1992; Gould 1993). I had been told by a member of Darwin-L that I could find Dennett's thoughts on Gould in his new book (Dennett 1995). While I did find some thoughts I was more confused than when I started. This chapter is full of what seems to me to be at best uncharitable and at worst willful misreadings of Gould's writings. He paints Gould as some kind of anti-Darwinian throughout (compare Gould 1977). I can't imagine Gould agreeing to this characterization. Gould gets kudos for his 20+ year education of the American public and his anti-creationist stance. Ah, but his prolific educating is but a way to fulfill his various agendas. One of these is Gould's resistance to ultra-Darwinism which Dennett synonymizes with "his" no-skyhooks Darwinism. We find that Gould goes from one revolution to the next "crying wolf" (defying the moral of Aesop's fable). This all amounts to the idea that Gould rejects "the very idea that evolution is, in the end an algorithmic process." Given Dennett's attenuated all-inclusive sense of algorithm, what does this mean? "The 'no skyhooks-allowed' Darwinism I have presented is, by Gould's lights, hyperDarwinism, an extremist view that needs overthrowing" (pg. 264 Dennett 1995). This sentence implies that Gould's description is pro-skyhooks, that hyper-Darwinism is identical with Dennett's previous presentation of neo-Darwinism, and that Gould buys this arrangement of the furniture. I don't think that Gould would agree with or most fair readers would find in Gould a sky-hooks-allowed or -encouraged philosophy. Are we really to believe that neo-Darwinism is so free of empirical content that a priori no-skyhooks selectionism is all there is to it? Is Gould really tilting at a careful no just-so stories, contingency aware, adaptation for only some things Darwinism? I doubt it. He makes his targets clear. Dennett may think that he has been unfairly placed into the bullseye but if in fact he isn't a Panglossian then why is he so nervous? "After I began to notice that many of the most important contributions to evolutionary theory have been made by thinkers who were fundamentally ill-at-ease with Darwin's great insight, I could begin to take seriously the hypothesis that Gould himself is one of these." (pg. 267 Dennett 1995) If Dennett means that Gould is one of the important contributors to evolutionary theory who is interested in more than a priori selectionism then I suspect that even Gould would thank him for the compliment. But it isn't meant that way - and probably won't be taken as a praise. What is it that Dennett thinks all of those important contributors are doing with their time? We have to (at least formally) allow that maybe their discomfort is with the kind of universalized Darwinism that Dennett wants to synonymize with what is presented in Darwin's work as seen through the eyes of Dawkins. Dennett challenges the spandrels of San Marco paper (Gould and Lewontin 1979). This is Gould and Lewontin's forceful statement against explaining every feature as an adaptation. Dennett insists that none of the befuddled biologists who use this paper as a corrective for their students know what they are talking about (pg. 267-282 Dennett 1995). Poor Dennett, even his ally Maynard-Smith allows that "By and large, I think their paper had a healthy effect. There are plenty of bad adaptive stories... Their critique forced us to clean up our act and to provide evidence for our stories." (Maynard-Smith 1995) So contra Maynard-Smith Dennett claims that Gould was preaching to the converted and no "good" evolutionists ever went to the excesses that the Panglossian adjective implied. How could Dennett get it so wrong? Maybe the path of the argument will help. We are treated to a long explanation of how domes can be placed on walls without forming spandrels (which it turns out aren't even really called 'spandrels'). And it goes on and on - only to end by claiming that in fact not all features are adaptations; "Natural selection could still be the 'exclusive agent' of evolutionary change even though many features of organisms were not adaptations." This simply moves the goal post. If we synonymize 'evolutionary change' with 'natural selection' then sentences like the above are not very interesting. Dennett's discussion of the Spandrels paper shows a pattern of an obsessive attention to the wrong details. The spandrels paper is used and taught often because people do make the "adaptations everywhere" mistake. Dennett's treatment of Gould and Vrba is curious, because he seems to buy (completely) the notion of appropriation of features that weren't designed for their current use. In fact, his no skyhooks rule requires this of him. He seems to be saying that since you can go back to a time when "you will find that every adaptation has developed out of predecessor structures each of which had some other use or no use at all" (pg. 281 Dennett 1995) that there is no useful category for features not evolved under natural selection for their current use. Does allowing this formal notion (everything is an exaptation) gut the word of any utility? Most of the molecular evolutionist I know don't seem to think they need this word. But they certainly have the situation arise. Let me illustrate with an example from protein evolution (others have had plenty to say about organ-level exaptations (Gould and Vrba 1982)). A protein involved in (5) transporting soluble antibodies from mother's milk across the lumen of the gut (FcRn) is a heterodimer. The heavy chain of FcRn is related to the MHC class I proteins (paralogously) (6). There is some circumstantial evidence that these proteins diverged around the time of the ancestor to lizards and mammals(Ahouse, Hagerman et al. 1993). One of the domains of Ameiva lizard MHC class I is slightly more similar to part of the mouse FcRn heavy chain than the same domain from the MHC of other mammals. This conclusion has recently received support from a group who has examined the genomic structure of the mouse gene (Kandil, Noguchi et al. 1995). It turns out that FcRn uses a very different part of the molecule to bind its ligand (the antibody) that the MHC molecule does to bind its ligand (a peptide) (Burmeister, Huber et al. 1994). Importantly the binding is not near the MHC peptide binding groove. Is this an example of what Gould and Vrba call 'exaptation'; "=8Afeatures of organisms are non-adapted, but available for useful cooptation in descendants" (Gould and Vrba 1982)? The domain that is coopted for the function of binding in FcRn may be critical for the function of MHC - just not used for binding and subsequently appropriated. In this context it could have a coherent use, since we aren't really ready to move back to the ancestor of all MHC extracellular domains. Dennett tells us that Gould has complained that the target of his criticism is moving (pg. 281 Dennett 1995). Gould's frustration that the neoDarwinian synthesis doesn't sit still, adsorbing and embracing new ideas as they make themselves known shouldn't get too much sympathy. At the same time, being able to rapidly cleave to new ideas is not the same as always having stood for them yourself. Dennett repeatedly belittles Gould's contributions by claiming that they were always there. Priority is important and no one likes to be grabbed by the collar and told passionately how important it is to believe what one already believes. So Dennett will need to argue more convincingly that all of Gould's mild correctives were an extant and vivid part of the synthesis to bring me on board. Dennett then moves to a discussion of punctuated equilibrium (7). He does what he can to confuse a straightforward central claim; morphological stasis is found throughout the fossil record. Adaptive gradualism does not lead us to expect this. That's the main point. Dennett confuses the issue (as others have) by focusing on the punctuations not the equilibrium. It is stasis that is surprising in a gradualist all features varying world. How would you explain stasis if you don't let yourself appeal to constraints in variation? You would depend on stabilizing selection - as people have. But claiming that all stasis is due to stabilizing selection is a controversial move. Is it discussed as such by Dennett? Nope. He offers us the idea that species are intrinsically conservative, that species are tracking stable environments, and that it is due to a purely theoretical explanation (that we aren't told about) and from this we are to conclude that, "It is quite clear, then, that equilibrium is no more a problem for the neo-Darwinian than punctuation" (pg. 294 Dennett 1995). Gould and others have taken the observation about stasis to make plausible species sorting as an explanation in macroevolutionary dynamics (Gould and Eldredge 1993; Gould 1994). The discussion regarding species selection is ongoing and enthusiasm for or against it seems to have everything to do with what scale you are examining. In explaining the diversity and abundance of various forms at a particular time and place we press a number of explanatory machines into service. Dennett, it seems, would insist that every (evolutionary?) feature of distribution and abundance is best explained by local adaptation. Is this true? Certainly not. We are then left with the issue of deciding what features to foreground as we tell the story of life. Parts of that story invite highlighting adaptationism (the changes in primate limb structure (Fleagle 1988)) others macroevolutionary dynamics (extinctions in the marine fossil record (Raup and Sepkoski 1982)). What do we know about variation and the accessible morphological neighborhood? The last few years have yielded a bounty of information. Much of this work has come as thanks to years of Drosophila genetics (let us bow our heads in thanks to all those technicians and post-docs who maintained inbred lines for all those years!). One of the important parts of the adaptationist tale has been the idea that similar environments can generate similar solutions (convergence or parallelism). Examples that are often marched out involve the similar forms of marsupial and placental mammals (the marsupial cat and dog and the placental rabbit that moves just like a kangaroo) or the streamlining that is shared by dolphins and tuna. Not bad examples. The other side offers long lists of organisms that don't have convergent partners, my favorite is the woodpecker. So what happens when one of the favorite examples from one column is yanked into the other... The evolution of the eye stood for years as an example of independent evolution fulfilling the same need. Vertebrates and mollusks have single lens eyes (though the photoreceptive cells under the lens have opposite orientation) while insects have compound eyes. These differences had been taken to imply that the eye evolved (independently) numerous times (Salvini-Plawen and Mayr 1977). Now it looks (pun!) as if the large morphological differences share a common developmental pathway for eye morphogenesis. The evidence for homology in the developmental pathways comes from looking at the orthologous protein in mammals and flies. The original paper claiming homology between mouse (Pax-6) and fly (eyeless) was in 1994 (Quiring, Walldorf et al. 1994). Subsequent work in the same lab showed that misexpression of the eyeless protein could give rise to eyes on wings and legs. This story was reviewed in Natural history in December of that year (Gould 1994) and a nice review recently came out in Current Opinion in Genetics & Development this year (Halder, Callaerts et al. 1995). What do we take from this deep homology? Does this mean that there is no selection - of course not! But it does sensitize us to the importance of the lineage and suggests that at a minimum if there is even the slightest backdrop that can be used in a new context this developmental path has been followed and more challengingly maybe selection doesn't have the latitude that we might want to give it. If the Pax-6 cascade hadn't been extant in the lineage that led to insects, chordates and mollusks would there have been eyes in these lineages? Can the variation that selection operates on include a visit to the past? Anyone interested in animal development these days will find themselves learning about a group of genes called the Hox genes. These genes originally identified because their mutant forms resulted in transformations of body segments are fascinating. These mutants underline the ability of small genetic changes to have profound morphological consequences (not news - but underlined nonetheless). Even more fascinating is recent work showing that changes in some Hox genes can result in ancestral morphologies reemerging. The ancestral condition for the mammalian ear ossicles is a single bone homologous to the stapes (stirrup). The familiar malleus (hammer) and incus (anvil) are derived from the articular (lower jaw) and quadrate (upper jaw). Scrambling the Hoxa-2 gene in mice changes the pharyngeal arches during development resulting in the ancestral condition (Lufkin, Mark et al. 1992). A similar thing is seen in Hoxb-8 and Hoxc-8 manipulations where rib and vertebral atavisms are seen (Pollock, Tadru et al. 1995). The ancestral one wing per segment can be seen in manipulations of insect Hox genes (Carroll, Weatherbee et al. 1995). The hypothesis that flowers derived from leaf tissue is lent support by plant mutants that show whole flower structures where anthers, stamens, petals and sepals can be replaced by leaf tissue (Weigel and Meyerowitz 1994). This should not be taken to imply that the intricate derived states (getting the four whorls of flower tissue from leaf tissue) are only a couple of mutations away from the ancestral condition, rather these mutations emphasize that certain (surprising?) forms are close to extant forms and evolutionary dynamics may be dependent on the possibilities that are "stored" in these developmental pathways. (see also Day 1995) I raise the examples of deep homology and atavism to remind you where one of the foci of current discussion in evolutionary biology rests. The argument is not in some kind of tension between mystics and realists. To read Dennett you wouldn't get the sense that any of this was happening. How misleading is it to write a book that avoids the current intellectual activity in the discipline? Dennett ends his chapter on Gould with a discussion of Gould's Burgess Shale book (Gould 1989). Dennett writes, "Gould speaks here not just of unpredictability but of the power of contemporary events and personalities to "shape and direct the actual path" of evolution. This echoes exactly the hope that drove James Mark Baldwin to discover the effect now named for him: somehow we have to get personalities - consciousness, intelligence, agency - back in the driver's seat. If we can just have contingency - this will give the mind some elbow room so it can act, and be responsible for its own destiny, instead of being the mere effect of a mindless cascade of mechanical processes! This conclusion, I suggest, is Gould's ultimate destination, revealed in the paths he has most recently explored." - (pg. 300 Dennett 1995) This doesn't resonate with my take on Gould's project. I leave it to you to put this analysis somewhere on the spectrum from on-target to uncharitable to misleading. Jeremy C. Ahouse Biology Department Brandeis University Waltham, MA 02254-9110 ph: (617) 736-4954 fax: (617) 736-2405 email: ahouse@hydra.rose.brandeis.edu _ _ /\\ ,'/| "Truly speaking, _| |\-'-'_/_/ it is not instruction, __--'/` \ but provocation, / \ that I can receive / "o. |o"| from another soul." | \/ - R.W. Emerson \_ ___\ `--._`. \;// ;-.___,' / ,' _-' _______________________________________________________________________________ Darwin-L Message Log 28: 1-17 -- December 1995 End