Hugo de Vries

Dutch botanist

• Born: February 16, 1848; Haarlem, Netherlands
• Died: May 21, 1935; Lunteren, Netherlands

Working in the late nineteenth and early twentieth centuries, Dutch botanist Hugo de Vries was instrumental in rediscovering geneticist Gregor Mendel’s laws of heredity. In addition, de Vries helped establish the modern science of genetics with his theory of intracellular pangenesis, and his mutation theory paved the way for debates about the nature of evolutionary change.

Primary field: Biology

Specialties: Botany; genetics; evolutionary biology

Early Life

The oldest son of Gerrit de Vries and Maria Everardina Reuvens, Hugo de Vries was born into a family of scholars, lawyers, religious figures, and statesmen. After working as a lawyer for some time, Gerrit was appointed to the Council of State and moved his family to The Hague; he later became prime minister of the Netherlands, serving from 1872 to 1874.

During his childhood, de Vries attended a private Baptist grammar school in Haarlem and later attended the local gymnasium, or secondary school. He spent his free time and his longer vacations exploring the countryside, searching for plants to fill his herbarium. Due to his burgeoning interest in botany, he built numerous herbariums, occasionally winning prizes for them. After the family moved to The Hague, the young de Vries occasionally spent time in Leiden, where he met the botanist Willem Suringar. Suringar asked de Vries to help him classify the plants kept by the Netherlands Botanical Society.

In 1866, de Vries entered Leiden University. Under the influence of Julius Sachs’s 1868 botany textbook Lehrbuch der Botanik, de Vries developed an interest in plant physiology. During these years, he also discovered Charles Darwin’s treatise On the Origin of Species (1859), which piqued his interest in evolution.

Life’s Work

In 1870, de Vries moved to Germany’s Heidelberg University to study chemistry with Wilhelm Hofmeister. Six months later, in the spring of 1871, he moved to Würzburg, Germany, where he studied with Julius Sachs and worked in his laboratory and contributed to Sachs’s journal by writing a number of reports on his experimental work. Although he taught natural history at the First High School in Amsterdam from 1871 to 1878, de Vries returned in the summers to Sachs’s laboratory at Würzburg in order to continue his experiments in plant physiology. Over the course of these seven years, de Vries produced a number of monographs on red clover, potatoes, and sugar beets, and his articles on cell growth in plants attracted wide attention. His article on the mechanism that causes tendrils to curve in plants prompted Darwin’s admiration for de Vries and the two men began a long correspondence.

De Vries moved to the University of Amsterdam in 1878, becoming the equivalent of a tenured professor in 1881. It was there that he conducted his famous experiments on protoplasm, plasmolysis, and plant osmosis. Through these experiments, he discovered that the inner lining of the cell wall, the protoplast, consisted of three layers, not two, as most plant physiologists believed at the time. He also determined that vacuoles, small cavities containing fluid in the cell, have their own linings, and he performed research on protoplasm in insectivorous plants.

Late in the 1880s, de Vries’s interests, influenced by his deep reading of Darwin, shifted to questions regarding inheritance and variability. In his book Intracellular Pangenesis (1889), de Vries argued that hereditary traits of living organisms are independent units (pangenes) that reside in cells’ nuclei. De Vries used this theory to explain how a cell develops into an organ, how metamorphosis occurs, and how offspring develop and maintain uniformity with parents. He argued that hereditary traits of a genus can be traced to large aggregates of pangenes that remain unchanged in the offspring; extraordinary changes during the division of cells, however, result in the creation of a different pangene, which results in a new characteristic of an organism. Thus, according to de Vries, evolution proceeds by this pangenetic mechanism. Twenty years later, Danish botanist Wilhelm Johannsen shortened de Vries’ term pangenes to genes.

In order to support his own work on pangenesis, de Vries conducted numerous experiments involving the hybridization of several plant species. Through such experiments and his reports on them, he rediscovered Mendel’s 1866 paper on the experiments with peas that led to Mendel’s formulation of his genetic laws. Following de Vries’s rediscovery of Mendel’s laws, many other scientists took up Mendel’s ideas regarding hybridization and genetics. However, de Vries believed that hybridization failed to account for the appearance of new species, and rather than building on Mendel, he set out to explore the phenomenon of mutation, which he thought provided the details for and advanced the theory of evolution.

Beginning his experiments with a species of evening primrose in 1886, de Vries noticed new variants in the species. Amongst a garden plot in which the parent primrose grew, a number of offspring grew that were distinct enough to be single variations of the parent and for de Vries to call mutants. He hypothesized that during its evolutionary life, a species produces mutants over isolated and relatively short periods of time. Sometimes permutation periods, during which the hereditary traits are formed, precede the periods of mutation. De Vries developed his ideas at length in a two-volume work, Mutation Theory (1900–1903), which became the foundation of an evolution theory that proposed that abrupt periods of mutations were responsible for propelling evolution, rather than a gradual, continuous process of adaptation and selection.

In May 1905, de Vries was elected Foreign Member of the Royal Society of London. He also acted as a correspondent for and member of various other societies, including the Russian Academy of Sciences, the Prussian Academy of Sciences, and the Academia dei Lincei in Rome, Italy. He retired from the University of Amsterdam in 1918 to his estate in Lunteren, where he continued to conduct experiments in his vast experimental gardens until his death in 1935.

Impact

While de Vries may be best known today for his rediscovery of Mendel at the end of the nineteenth century, his work on mutation theory and evolutionary biology continues to have significant and lasting ramifications for the subject. While numerous scientists posit that evolution develops through a gradual process of adaptation and the inheritance of adaptive traits, others argue that evolution advances by jumps or macromutations, a theory known as saltationism. De Vries was one of the first saltationist geneticists to advocate for mutations as the mechanism that drives the evolutionary process.

De Vries’s ideas about the genetic basis of mutation, including his isolation of the pangene as the unit in which mutation occurs, anticipate much modern scientific work on the genetic basis of evolution. The mutation researchperformed by de Vries and other early geneticists provided the foundation for work by later evolutionary biologists such as Richard Dawkins. De Vries’s work may also have influenced American geneticist T. H. Morgan, who, with a group of other scientists, conducted experiments on the genetics of fruit flies (Drosophila) that became the foundation for the modern chromosome theory of heredity.

Bibliography

Bowler, Peter J. Life’s Splendid Drama: Evolutionary Biology and the Reconstruction of Life’s Ancestry, 1860–1940. Chicago: U of Chicago P, 1996. Print. Offers an account of how various scientists have used de Vries’s ideas about mutation as the basis for evolutionary theory in contemporary debates about the history of evolution.

Ridley, Matt. The Agile Gene: How Nature Turns on Nurture. New York: Harper, 2004. Print. Provides an account of genes as the foundation of an evolutionary theory of behavior, proceeding from de Vries’s early theory of genetics.

Ruse, Michael, and Joseph Travis, ed. Evolution: The First Four Billion Years. Cambridge, MA: Harvard UP, 2009. Print. Contains short essays on major scientists who have made an impact on the study of evolution, including a brief introduction to de Vries’s work and his role in shaping the conversation about evolution.