Crampton, Henry Edward
CRAMPTON, HENRY EDWARD
Crampton was the son of Henry Edward Crampton, Sr., a physician, and Dorcas Matilda Crampton (née Miller). He attended the College of the City of New York, switching to Columbia University, where he received his A.B. in 1893 and his Ph.D. in zoology in 1899. While pursuing graduate studies, he served as an assistant in biology at Columbia (1893–1895) and as instructor at the Massachusetts Institute of Technology (1895–1896). He married Marion M. Tully on 27 October 1896; they had one daughter and one son.
Crampton resumed teaching at Columbia in 1897 and remained there for the rest of his career, primarily instructing women at Barnard College. He achieved the rank of professor in 1904 and retired in 1943. Crampton taught the embryology course at the Marine Biological Laboratory in Woods Hole (1895–1902) and was in charge of embryology at the Cold Spring Harbor Lahoratoiics (1903–1906). He also served as curator for invertebrate zoology at the American Museum of Natural Histor (1909–1920) and was associated with the Carnegie Institution of Washington and the Bishop Museum (Honolulu). Crampton was a fellow of the New York Academy of Sciences and served as its president in 1926. He also served as vice president of the American Society of Naturalists (1921), vice president of the American Society of Zoologists (1911), and secretary-treasurer of the Eugenics Society of the United States (1922–1925).
Crampton’s career and its development serves as a fine epitome of general trends within evolutionary biology during his lifetime, from the strong interest in embryology that pervaded late-nineteenth-century work to the rediscovery of Mendelism and the nonadaptationist consensus (for differences among geographic variants and closely related species) that prevailed into the 1940’s, before the Modern Synthesis reasserted the shaping power of selection at these scales. But Crampton was no passive reflector of these trends: his three massive, meticulously detailed, and beautifully illustrated monographs on the land snail genus Partula from Pacific Islands (1917, 1925, 1932) were primary documents in the development of this consensus.
Crampton studied at Columbia when its biology department, led by H. F. Osborn, E. B. Wilson, B. Dean, and A. Willey was a center for embryological and evolutionary studies, the two foci of Crampton’s career. Crampton’s early research was predominantly embryological; he also taught embryology at Woods Hole and Cold Spring Harbor. He performed important experiments on cleavage in isolated blastomeres of gastropods and on crossspecies fusion in insect larvae and pupae. C. B. Davenport, in nominating Crampton (unsuccessfully) for the National Academy of Sciences, wrote that “nobody has been quite so successful in grafting insect larvae as [Crampton].”
In 1899 Crampton began a series of selection experiments on pupae of cynthia moths (published in Biometrika in 1904 and in the Journal of Experimental Zoology in 1905). He followed the work of Bumpus and Weldon in focusing upon selective elimination and differences in character means between pupae that died and those that survived to produce an imago. He was puzzled that he could demonstrate selection, but on characters that could not have influenced mortality directly (for example, on antennae not used by the pupae). He decided that selection must work for a harmonious pattern of correlation among characters, not usually on individual traits themselves, and that internal factors of development are as important to success as the match of traits to environmental dictates. He wrote in 1905: “Selection is not regarded as in any way originative but only as judicial, so to speak. As the members of any species present themselves at the bar,’ selection’ decides the question of survival or destruction on the basis of the condition of correlation that is exhibited.” This balance of emphasis on internal and external forces was characteristic of late-nineteenth-and early-twentieth-century evolutionary thought.
Crampton became dissatisfied with a purely laboratory approach to evolution and decided to study a case of diversification and speciation in nature. Beginning in 1906 and extending through the mid-1930’s Crampton undertook numerous expeditions to islands of the Pacific, where he studied the protean and prolific land snail Partula (primarily on Tahiti and Moorea), Partula presented many advantages for such work: it exhibits remarkable variation in color and coiling, often with distinct local races in each valley; and parents brood offspring, which can be dissected out, facilitating the understanding of inheritance in shell traits.
Crampton’s three monographs on Partula. published by the Carnegie Institution, are among the greatest works of twentieth-century American natural history, Following themes established by J. T. Gulick in his 1905 monograph (also published by the Carnegie Institution) on Hawaiian land snails of the genus Achatinella. Crampton explored the roles of environment, isolation, mutation. and selection in the origin of species and geographic races. In his first monograph on Partula in Tahiti (published in 1917, though the title page reads 1916), Crampton studied and presented statistical summaries (all done by hand or with the simplest calculating machines) for data on 80, 000 adult shells from more than 200 valleys.
Against Lamarckism (then current among many naturalists), Crampton decided that environment plays no originative role in the evolution of new variants. But since Crampton could find no correlations between shell variation and environment, he also concluded that natural selection is not an originative force, but can only act to eliminate inadaptive features. Adaptation, which Crampton regarded as universal (see his popular books of 1911 and 1931), is not built gradually by natural selection at these small scales, but arises fortuitously and “congenitally” (Crampton’s favorite term) and is then preserved by selection acting in an eliminative role. Crampton therefore emphasized the primary roles of isolation, as a precondition for divergence (geography produces nothing directly but establishes a situation in which new features can spread), and mutation, as a source of fortuitous variation that can then become established in isolated populations.
The resulting pattern of differences among valleys is largely nonadaptive. Every local race must avoid elimination by natural selection (and is adapted in this sense), but its particular features represent but one among hundreds of workable possibilities, and the initiation of one or another among the numerous possible solutions is set by isolation and congenital variation (mutation), not by natural selection. This nonadaptive interpretation of small-scale variation represented a consensus among field taxonomists before the 1940’s, and Crampton’s monographs provided powerful support, “Therole of the environment.” Crampton wrote, “is to set the limits to the habitable areas or to bring about the elimination of individuals whose qualities are otherwise determined, that is, by congenital factors” (1917, p. 299).
Crampton regarded his views as within the Darwinian orbit. He wrote two popular books extolling the Darwinian world view (1911 and 1931). Still, his insistence that natural selection can be only an eliminative force, and that everything about the origin of entire new traits (not only of small-scale favorable mutants) must be ascribed to “congenital factors,” placed him outside the stricter Darwinism of the Modern Synthesis as it developed during the 1940’s and 1950’s. In his last monograph Crampton summarized his notion of natural selection; “Congenital variation must not be eliminative” is the correct statement of the categorical imperative of organic differentiation, and I do not regard it as contradictory to the contentions of Darwin in any essential respect” (1932, p. 188). Nonetheless, Crampton’s vision of natural history, with its large role for nonadaptive differences among local races and species, lost its popularity late in his lifetime, and Crampton himself became a forgotten figure. This eclipse is most unfortunate because Crampton’s Partula monographs were very influential and represent an important era in evolutionary thought. Moreover, many of his ideas are getting a rehearing during renewed modern debates about evolutionary mechanisms. W. Provine, for example, demonstrates how important Crampton’s views were to Sewall Wright as he developed his shifting balance theory of evolution (Sewall Wright and Evolutionary Biology, 1986). Students of land snails (the author of this article is one) continue to hold Crampton’s work in highest regard— and to use his numerical data, surely a sign of ultimate respect for a scientist.
The crux of Crampton’s career and the source of his importance lie in his three great monographs on Partula. published by the Carnegie Institution of Washington, Studies on the Variation, Distribution, and Evolution of the Genus Partula. I. The Species Inhabiting Tahiti (1917), II. The Species of the Mariana Islands, Guam, and Saipan (1925), and III, The Species Inhabiting Moorea (1932). Crampton set out his views on evolution in two books intended for general audiences: The Doctrine of Evolution: Its Basis and Scope (New York, 1911) and The Coming and Evolution of Life (New York, 1931). See also “Experimental and Statistical Studies upon Lepidoptera.” in Biometrika, 3 (1904), 113–130: and “On a General Theory of Adaptation Selection,” in Journal of Experimental Zoology, 2 (1905), 425–430.
Stephen Jay Gould