CHARLES ROBERT DARWIN (1809-1892)

Charles Darwin was born in Shrewsbury, England. Charles Darwin's grandfather was the naturalist, philosopher and doctor Erasmus Darwin, who had published a four volume treatise containing his own views on the development of the species. Charles Darwin's father was also a physician, and wanted his son to carry on the family tradition. At 16, Darwin was sent to Edinburgh University to study medicine. Darwin was more interested in his zoology and geology classes. Eventually, his father withdrew him from Edinburgh and sent him to Cambridge to study divinity.

In 1831, Darwin was invited by Captain Fitz-Roy to be the science officer on the H.M.S. Beagle on an exploratory survey. During the next five years, the Beagle toured the South American coasts, the Galapagos Islands, New Zealand, Australia and South Africa. The voyage was an eye-opening experience for Darwin. He collected, sketched and made notes of fossils, and a wide assortment of living organisms. Based on what he saw, Darwin believed that life evolved, and could be traced through fossils and living examples. In this he was influenced by what he knew of geology and the stratification of rock layers. Darwin concluded that the adaptations and changes in many of the species he saw, especially the finches and tortoises on the Galapagos Islands, came about through a process of natural selection.

On his return to England in 1836, Darwin did not immediately publish his theory on evolution. He spent time sorting and cataloguing his collection of material, and publishing popular accounts of his voyage on the Beagle. In 1857, a young biologist, Alfred Russel Wallace, sent Darwin a letter outlining the "theory of evolution through natural selection." Wallace wanted Darwin's opinion and possible endorsement for presentation of the theory to the Linnean Society of naturalists. Darwin recognized the similarity of his work to Wallace's, and actually offered to burn his own work to avoid being thought of as an idea stealer. In the end both Darwin and Wallace presented the theory to the Linnean Society. It was Darwin's book however, On the Origin of Species, published in 1859, which garnered all the attention and the controversy. The book had a profound impact on the social, religious, political and scientific thinking of the general public and the scientific community. Darwin himself was uncomfortable with all the controversy and avoided it whenever possible.

Darwin wrote and published books and papers on other subjects relating to natural history, The Variation of Animals and Plants under Domestication (1868), The Descent of Man (1871). Darwin never forgot Wallace's contributions to the natural selection theory. Darwin died in 1882 and is buried in Westminster Abbey.

GEORGE HARRISON SHULL (1874-1954)

George Shull was born on a farm in Clark County, Ohio, and his knowledge of plants and hybrids came at an early age. Shull's father was a farmer and his mother was an amateur horticulturist. Being needed on the farm, Shull's early formal education was sporadic. However, it was supplemented by intense home study such that by 1892, he was teaching public school, and attending Antioch College.

In 1901, he graduated from Antioch, and went to the University of Chicago to do graduate work. With his knowledge of botany and experience with farming practices, Shull passed a Civil Service exam, and was appointed as Botanical Assistant at the U. S. National Herbarium. He also worked at the U. S. Bureau of Plant Industry as a Botanical Expert examining the flora and fauna of Chesapeake Bay and Currituck Sound. The data he collected during this time was to comprise his Ph.D. thesis. However, Shull had become interested in the statistical analysis of variation in plants. He contacted Charles Davenport at the Station of Experimental Evolution, and in 1904 was appointed to be in charge of plant work at the Station. Shull published his uncompleted Ph.D. thesis as a paper, and went to Cold Spring Harbor.

At Cold Spring Harbor, Shull studied and bred a large variety of plants, for example, the evening primrose (Hugo de Vries' favorite species), shepherd's purse, corn and peas. He published many papers on his observations of plant traits and inheritance. In 1905, he began work on corn, maize, with the intent of examining the quantitative inheritance of corn traits. Following Mendel's example, Shull obtained pure-bred lines of corn through self-pollination. The pure-bred lines were less vigorous and productive, but when he crossed the pure-bred lines, the hybrid yields were better than any of the parents or those pollinated in the open fields. He immediately recognized the potential for using this strategy to improve crop yields. By the 1930's and 40's, most farms were growing the hybrid stocks, and improved yields contributed greatly to the war effort and the rehabilitation of post-war Europe.

In 1915, Shull accepted a professorship at Princeton University. At his instigation, Princeton University Press began the publication of a new journal, Genetics. Shull was the managing editor for ten years. Genetics is still one of the top international science journals.

Shull retired in 1942. He and his wife spent most of their twilight years with their children and grandchildren.