Richard Weikart, "A Recently Discovered Darwin Letter on Social Darwinism," Isis 86 (1995): 609-611.
For many decades, historians have debated whether Darwin was himself a social Darwinist, i.e., someone who believed that human beings were and should be subject to the same competitive forces acting on all other living things. The debate is sharpened by the poor standing of social Darwinism, which sanctioned a wide spectrum of abuses. In 1993, historian Richard Weikart (California State University) discovered an 1872 letter from Charles Darwin to Heinrich Fick, a law professor at the University of Zurich, that sheds new light on Darwin's views of the application of his own theory to human beings. "It is the strongest piece of evidence of which I am aware," writes Weikart, "that Darwin himself believed that his biological theory lent support to individualist economic competition and laissez-faire economics" (p. 609). In the letter, Darwin complains that trade unions in England have insisted "that all workmen -- the good and bad, the strong and weak,--sh[oul]d all work for the same number of hours and receive the same wages." But this, Darwin avers, "seems to me a great evil for the future progress of mankind," as it will "exclude competition." Here Darwin departs from his usual circumspection, Weikart argues, to apply his theory directly to the social conditions of humanity.
Stanley L. Miller and Antonio Lazcano, "The Origin of Life -- Did It Occur at High Temperatures?" Journal of Molecular Evolution 41 (1995): 689-692.
Arguably the grandest old man of origin of life studies, Stanley Miller and his Mexican colleague Antonio Lazcano here consider critically the hypothesis that life began at high temperatures -- 90° C or more. The hypothesis is based on the argument that the oldest living things are hyperthermophilic bacteria, which grow optimally at high temperatures. Miller and Lazcano allow that while hyperthermophiles may be ancient, they are certainly not "primitive," and possess metabolic machinery similar to other bacteria (p. 690). Moreover, although higher temperatures give higher reaction rates, possibly favoring primitive (inefficient) enzymes, the price must be paid in "loss of organic compounds by decomposition and diminished stability of the genetic material" (p. 691), due to the greater heat. "RNA and DNA are clearly too unstable to exist in a hot prebiotic environment. The existence of an RNA world with ribose appears to be incompatible with the idea of a hot origin of life. The stability of ribose and other sugars is the worst problem, but pyrimidines and purines and some amino acids are nearly as bad" (p. 691). Miller and Lazcano conclude that the special features of hyperthermophile bacteria, which enable them to survive in high temperature environments, may be secondary adaptations, and therefore not as ancient as believed. On that view, "hyperthermophiles are not the oldest organisms" (p. 693), and a hot origin of life is unwarranted by the evidence.
Carl E. Bauer and Terry H. Bird, "Regulatory Circuits Controlling Photosynthesis Gene Expression," Cell 85 (1996): 5-8.
Purple photosynthesic bacteria know how to make the best of any situation. "Many of these organisms," Bauer and Bird (Biology, Indiana) report, "can obtain cellular energy from light, inorganic compounds, or organic compounds, depending on the chemical and physical conditions of the environment" (p. 5). To do so, however, the bacteria must regulate their alternative modes of energy production to avoid using the wrong system -- and they do so with a complex battery of gene circuits. "Contemporary studies involving Rhodobacter capsulatus [a photosynthetic bacterium] have revealed a remarkably complex circuitry that regulates expression of photosystem genes in response to alterations in oxygen tension and light intensity" (p. 5). This handsomely illustrated review explains the aerobic, anaerobic dim light, and anaerobic high light gene circuits, stressing their interactive complexity: all this in organisms that could easily hold a convention of thousands in the period at the end of this sentence.
Alex Rosenberg, "A Field Guide to Recent Species of Naturalism," British Journal for the Philosophy of Science 47 (1996): 1-29.
Rosenberg, a leading philosopher of biology now at the University of Georgia, explains the centrality of Darwinism for those philosophers of science who have taken "the naturalistic turn." Like the hedgehog in Isaiah Berlin's metaphor of the fox and hedgehog, contemporary philosophical naturalists know one big thing "that makes almost everything else coherent" (p. 3), claims Rosenberg -- and that is Darwinism. "Of all the well-confirmed theories in modern science," he writes, "it is the one with most direct relevance for the human condition, human behavior, and its cognitive causes. If any well-established theory can teach us about ourselves it is Darwin's" (p. 4). Furthermore, "to a large extent, Darwinian theory is to be both the model of scientific theorizing and the guide to philosophical theory because it maximally combines relevance to human affairs and well-foundedness." In addition to Darwinism, Rosenberg anchors naturalism in the fundamental principles of what he calls scientism (science "delivers the goods" [p. 25], he argues) and the rejection of "first philosophy" (i.e., epistemology from self-evident first principles). In Rosenberg's view, all our knowledge must inevitably wind its way back to Darwinian theory. One would like to see Rosenberg grapple with Alvin Plantinga's "evolutionary" argument against naturalism, or with Phillip Johnson's arguments in Reason In the Balance. Both contend that ultimately naturalism -- when grounded in or conjoined with Darwinian evolutionary theory -- is self-refuting, sweeping its feet out from under itself, into complete skepticism and irrationality.
A.H. Brush, "On the origin of feathers," Journal of Evolutionary Biology 9 (1996): 131-142.
"It has been a truism for most of this century," A.H. Brush (Physiology and Neurobiology, University of Connecticut) notes, "that feathers are related to reptilian scales." Yet, he continues, "the molecular evidence questions the simple, direct relation of the specialized structures of birds to reptile scale. I will provide arguments to show that reptile scales and feathers are related only by the fact that their origin is in epidermal tissue. Every feature from gene structure and organization, to development, morphogenesis and tissue organization is different" (p. 132). Feathers appear suddenly in the fossil record, Brush observes, as an "undeniably unique" character distinguishing birds (p. 133). Current approaches to the origin of feathers, Brush worries, tend to focus "on why feathers evolved or where feathers came from. At this juncture neither is as illuminating as to ask how they arose" (p. 133). Brush examines the protein structure of bird feathers and argues that it is "unique among vertebrates," with the "ancestral reptilian epidermal structure...still unidentified" (p. 131). He concludes: "At the morphological level feathers are traditionally considered homologous with reptilian scales. However, in development, morphogenesis, gene structure, protein shape and sequence, and filament formation and structure, feathers are different. Clearly, feathers provide a unique and outstanding example of an evolutionary novelty" (p. 140).
Iris Fry, "Are the Different Hypotheses on the Emergence of Life as Different as they Seem?" Biology and Philosophy 10 (1995): 389-417.
What does one need to assume, as a bare philosophical minimum, to conduct research on the naturalistic origin of life? Iris Fry (Cohn Institute for the History and Philosophy of Science, Tel Aviv University) contends that one cannot assume that life came to be as a cosmic accident or near-miracle, a view held by Jacques Monod, Karl Popper, Ernst Mayr, and Richard Dawkins, among others. "Biologists and chemists who claim today that the origin of life borders on the miraculous," she writes, "...suspend the scientific study of the origin of biological organization and create a barrier between biological evolution and the preceding stages of evolution, as well as between physics and biology" (p. 399). In short, she continues, they open the door to "Hoyle's teleological option" (p. 400), and despite their philosophical commitment to naturalism, imply "in fact, a creationist position." Scientific progress towards a naturalistic explanation of the origin of life is only possible, Fry argues, if one assumes "the continuity thesis," according to which (a) there are no unbridgeable gaps between inorganic matter and life, and (b) the emergence of life was highly probable. The continuity thesis is entirely a philosophical assumption, Fry notes. "The decision to adopt the continuity thesis is a philosophical one...and does not depend on the success of a specific experimental program, nor can it be revoked on the basis of its failure" (p. 393). To abandon the continuity thesis is simultaneously to abandon the search for a naturalistic explanation of the origin of life. Thus, philosophical assumptions and arguments, Fry concludes, go "to the core -- to the very 'right of existence'" (p. 414) of the naturalistic research program in the origin of life.
Daniel W. Fong, Thomas C. Kane, and David C. Culver, "Vestigialization and loss of nonfunctional characters," Annual Review of Ecology and Systematics 26 (1995): 249-68.
Darwin frequently twitted his creationist opponents about the apparently useless structures of many animals and plants. Surely an omnipotent creator could do better than this, he reasoned. Why do some birds have wings too short and small for flight; or cave animals, eyes that see nothing? The same argument has continued in evolutionary reasoning right to the present day. One response, from those favoring design, holds that many apparently useless structures are only apparently useless: careful study reveals their proper functions. One can also argue, however, that some vestiges and non-functional structures are, indeed, non-functional. Loss of complex biological information is far easier to explain, on design principles, than its natural de novo origin (and loss may be expected, given certain environmental changes, such as isolation of a population in a cave). In this useful review, Fong et al. cover a wide of range of examples of the reduction or loss of characters, including flightlessness in birds and insects, eye and pigment reduction in cave animals, loss of hearing, and decay of specific behaviors. While some of the discussion should be approached with caution (Fong et al. discuss the famous 1980 "hen's teeth" experiment, for instance, without noting that the experiment is now held in some doubt), this review helpfully summarizes a large literature.
Copyright © 1996 Paul A. Nelson. All rights
reserved. International copyright secured.
File Date: 11.14.96