Owen's Vertebral Archetype and Evolutionary Genetics-A Platonic Appreciation

OWEN'S VERTEBRAL ARCHETYPE AND EVOLUTIONARY GENETICS—A PLATONIC APPRECIATION SCOTT F. GILBERT* I Sir Richard Owen (1804-1892) is often cast as evolutionary biology's foremost villain. A believer in the successive emergence of organic life, he has been seen as a traitor to the idea of natural selection, a concept which he came close to formulating himself. Thus, he is presented, as his career rapidly declines, as a jealous man whispering antievolutionary calumnies into the anxious ear of Bishop Wilberforce [I]. Owen's demise at the hands of Darwin and Huxley was a public spectacle , and it is usually this aspect of his career which is given attention. But Owen's own theory of species formation, for which he fought so hard and in which he invested so much of himself, is fascinating in its own right. He was both a scientist and a philosopher, an English adherent to Germanic naturphilosophie whose theory concerning the origin of species represents a deftly integrated synthesis of paleontology, comparative anatomy, and Christian Platonism. It was this majestic aesthetic system which was one of the first casualties of Darwinism; for natural selection explained all too well the phenomena upon which Owen based his theories. Although resembling evolutionism in its advancement of the concept of successive speciation, it was in most other ways its opposite . Indeed, if Darwinism represents the replacement of type thinking by population thinking, Owen's theory was the epitome of the former. It was perhaps the culmination ofthat typological thinking ("essentialism") which Ernst Mayer has called the hardest obstacle that Darwinism faced [2]. ?Department of Zoology, University of Wisconsin, 1117 W. Johnson Street, Madison, Wisconsin 53706. I thank Dr. Camille Limoges for introducing me to the work of Sir Richard Owen. This essay was submitted to the second Perspectives Writing Award for Authors under 35 contest. O 1980 by The University of Chicago. 0031-5982/80/2303-0135$01.00 Perspectives in Biology and Medicine · Spring 1980 | 475 Owen's theory of the vertebral archetype can be seen as bridging the gap between the last modifications of the Great Chain of Being and the first statements of natural selection. Moreover, his way of thinking may have reentered modern biology—for his theories exhibit some remarkable "homologies" to current hypotheses for the molecular basis for evolution. When Owen published On the Archetype and Homologies ofthe Vertebrate Skeleton (1848), he found it necessary to place his work in the context of those continental "philosophical anatomists" whose work preceeded his own. Using his general introduction and historical critique to launch into his own theories, Owen placed himself as the heir to the traditions of Cuvier (his acknowledged master whose view of nature he wished to expand) and of those interpreters of nature, Goethe, Geoffroy St. Hilaire, Vicq d'Azyr, and Lorenz Oken. It is in this introduction to comparative anatomy that Owen best summarizes his own position. Without venturing into the evidence that Owen calls upon, we may state his conclusions below. First, he defines two terms critical to his discussion. "Homologue," which he had expanded from G. St. Hilaire's discussions (and to which St. Hilaire refers us back to "la philosophie Allemande"), pertains to "the same organ in different animals under every variety of form and function" [3, p. 6]. From this, he distinguishes the "analogue," that "part or organ in one animal having the same function as another part or organ in a different animal" [ibid]. For instance, "the hard parts of the leg of a Crab or an Insect may be analogous to the bones of the limb of a quadruped," Owen declared, "but they are not homologous with them." However, he would triumphantly conclude that "the arms and legs in Man, the fore- and hind-limbs of Beasts, the wings and legs in Bats and Birds, and the pectoral fins and ventral fins of Fishes ... all are homologous." Next, Owen describes the three types of homologies evident in the vertebrates: I. Special homology: the "correspondency of a part or organ, determined by its relative position and connections, with a part or organ ofa different animal; the determination of which homology indicates that such animals are constructed on...