BABCOCK, ERNEST BROWN

(b. Edgerton, Wisconsin, 10 July 1877; d. Berkeley. California, 8 December 1954)

botany, genetics.

The son of Emilius Welcome Babcock and Mary Eliza Brown Babcock, Ernest spent his childhood and early youth in Wisconsin; after a year (1895–1896) at Lawrence College in Appleton, Wisconsin, he moved to southern California. There he attended the Slate Normal School, Los Angeles (the parent institution of the University of California, Los Angeles), from which he graduated in 1898. After three years Babcock entered the University of California, Berkeley, from which he received a B.S. degree in 1906 and an M.S. in 1911. He accepted an appointment to the Berkeley faculty in 1907 and remained there until his retirement in 1947. Babcock married Georgia Bowem, a childhood friend, on 24 June 1908; they had no children.

As a young man Babcock was greatly impressed with the contributions that the exact study of inheritance, following Mendelian principles, could make both to the more efficient improvement of cultivated plants and to a deeper understanding of the processes of organismic evolution.

In 1913 Thomas F. Hunt, dean of the College of Agriculture, founded Berkeley’s department of genetics and appointed the thirty-six-year-old Babcock as its first chairman, with the rank of full professor. In 1916 Roy K. Clausen was appointed assistant professor. He and Babcock began the collaboration that led to the publication in 1918 of the textbook Genetics in Relation to Agriculture. The first work to unite these two fields, Genetics became widely popular throughout the United States and appeared in a second edition, revised and enlarged, in 1927. Along with Babcock’s twenty-five years as teacher of the introductory course on principles of plant and animal breeding at Berkeley it firmly established his preeminence as a teacher in his chosen field.

Babcoek’s research proved to be the first successful attempt to unite the disciplines of conventional systematics, plant geography, chromosome cytology, and the genetics of interspecific hybrids into an integrated analysis of species relationships and the origin of species. He selected the large genus Crepis, related to the dandelion in the aster family, because of the low chromosome number of one of its species, C, capillaries, on which Russian investigators, particularly Michael S. Navashin, had already conducted cytogenetic investigations. During the early stages of the project, Navashin spent almost two years at Berkeley to collaborate with Babcock.

Although Babcock originally conceived of cytogenetic research on C. capillaries that would be a plant counte)t of the outstanding investigations of Thomas Hunt Morgan and his associates on Drosophila, he quickly ran into technical difficulties that revealed the impractical nature of this approach At this point his close friend and scientific collaborator. Harvey M. Hall, honorary curator of the herbarium and a leading member of Berkeley’s botany department, suggested that a project designed to analyze cytogenetically the relationships and evolution of the numerous species of Crepis would prove to be exceptionally valuable. Babcock accepted Hall’s advice and revised his plans. With the aid of collaborators and students, he achieved notable success. The joint review of cytogenetics and evolution in Crepis, published in 1930 by Babcock and Navashin, was the first of its kind.

Babcock realized the importance of delimiting the genus Crepis by investigating related genera. To develop this part of the project, he added J. A. Jenkins and G. Ledyard Stebbins, Jr. to the group supported by his research grant. Their collaboration was close for six years. It resulted in two monographs, one on the Asiatic genus Youngia and the other on the endemic American species of Crepis. The latter set forth the concept of the agamic (asexual) complex, which placed in at rational evolutionbased system the relationships between a group of distinct sexual diploid species and the vigorous hybrids formed between them, hybrids that would have been sterile were it not for the fact that they had acquired the capacity to produce seeds by asexual means, parthenogenesis or apomixts.

During the early 1940’s Babcock gathered together all of the knowledge acquired during the previous twenty-two years of investigations. In 1947, his seventieth year, he published his two-volume monograph The Genus Crepis. This monograph still stands as a pioneer analysis. In it a number of varied and specific topics, such as conventional morphological differences, floral anatomy, and chromosomal differences, as well as geographical distribution and its relation to geological changes and plant migrations in general, are all brought to bear on two problems; the phylogenetie relationships of species and species groups, and the cytogenetic processes that underlie the origin of species.

Most of the general principles that emerged from Babcock’s research had already been recognized. Two of them, however, were new: (1) the concept of the agamic complex, already mentioned, and (2) the concept of phylogenetie reduction in chromosome number and size, worked out in collaboration with Navashin. The latter concept has gained renewed interest as DNA has become recognized as the major component of chromosomes. When noncoding or “spacer” DNA was identified as constituting the major portion of this substance in the nuclei of many plant species, an analysis of Crepis species with these facts in mind showed that differences between them involved not active genes but non-coding DNA. In appendix I of part I of his monograph he set forth his ideas about future research on the genus.

Babcock is remembered for his pioneering achievements in teaching genetics in relation to agriculture and in the integration of facts from numerous disciplines into a concerted effort to reveal trends and processes of plant evolution. He belonged to the Genetics Society of America, the American Genetic Association, and the Botanical Society of America, He was elected to the National Academy of Sciences (1946), became vice president of the American Society of Naturalists in 1934, president of the California Botanical Society in 1940, and president of the Society for the Study of Evolution in 1952. The University of California awarded him its highest honor, faculty research lecturer. in 1944.

During his final years (1953–1954) Babcock suffered from cancer: he died of it December 1954.

BIBLIOGRAPHY

I. Original Works. Published works by Babcock include Genetics in Relation to Agriculture (New York. 1918: 2nd ed. rev. and enl. 1927). with Roy E. Clausen: “The Genus Crepis.” in Bibliographia genetica. 6 (1930), I-90, with Michael S, Navashin: The Genus Youngia. Carnegie Institution of Washington Publication no. 484 (1937), with G. Ledyard stebbins, Jr.; The American Species of Crepis: Their Interrelationships and Distribution as Affected by Polyploidy and Apomixis, Carnegie Institution of Washington Publication no. 504 (1938), with G. Ledyard Stebbins. Jr.; The Genus Crepis. 2 vols (Los Angeles. 1947).

II. Secondary Literature. G. Ledyard stebbins, Jr., “Ernest Brown Babcock.” in Biographical Memoirs. National Academy of Sciences, 32 (1958), 50–66

G. Ledyard Stebbins. Jr.