Encyclopedia of Evolution.pdf - Online Reading Center

diately afterward, he attended the University of Kiev and
graduated with a degree in biology. He taught genetics at the
Polytechnic Institute in Kiev until 1924 when he joined the
genetics department at the University of Leningrad (now St.
Petersburg). Dobzhansky’s wife, Natalia Sivertzev, was also a
geneticist, and they conducted some joint research. Dobzhansky
was familiar with the work of Thomas Hunt Morgan at
Columbia University in New York. Like Morgan, Dobzhansky
decided to study the effects of genes and their interaction in the
fruit fly, which is still one of the major experimental organisms
in genetic studies (see DNA [raw material of evolution]).
In 1927 Dobzhansky had the opportunity to travel to
New York and work in Morgan’s lab. He went with Morgan
to the California Institute of Technology and received a faculty
appointment there. This proved fortunate for him, as it allowed
him to escape from the upheaval that was occurring in Russian
genetics. Mendelian genetics, which was universally accepted
by modern scientists, was being forcibly replaced by a version
of Lamarckism that was favored by the Soviet government (see
Lysenkoism). Dobzhansky remained in California until 1940,
when he returned to New York for a faculty appointment
at Columbia University. In 1962 he joined the faculty of the
Rockefeller Institute (now Rockefeller University), from which
he retired in 1970. Until his death in 1975, Dobzhansky taught
part-time at the University of California at Davis.
Dobzhansky did not confine his biological interests to
the laboratory. He loved to hike, and this brought him in
contact with the populations of natural species. This allowed
him to recognize the tremendous genetic variation that occurs
not just in laboratory populations of fruit flies but in every
natural population. He understood that mutations, which
produced genetic diversity, were usually numerous and had
small effects, and that these mutations were acted upon by
natural selection. Natural selection among these small mutations
was what produced new species (see speciation). In
this, he differed from the mutationist view, which prevailed
when he started his career. The mutationist view, championed
by prominent geneticists (see DeVries, Hugo), claimed
that mutations were large and that they produced new species.
Other architects of the modern synthesis were also biologists
who had observed the extensive variation of individuals
within wild populations (see Mayr, Ernst; Stebbins, G.
Ledyard). Dobzhansky’s book, Genetics and the Origin of
Species, published in 1937, was one of the most important
books in the modern synthesis.
Dobzhansky also applied his genetic insights to an understanding
of human evolution. Appalled by the racism that
had gripped Europe during the 20th century, Dobzhansky
defended the idea that there was more genetic variation within
races than between them, which meant that racial genetic differences
were not important in human evolution or in modern
society. He expressed these views in influential books such
as The Biological Basis of Human Freedom (1954), Mankind
Evolving: The Evolution of the Human Species (1962), and
Genetic Diversity and Human Equality (1973).
Dobzhansky was also a religious man, who maintained
his participation in the Russian Orthodox Church. He also
Dubois, Eugène
believed that the evolutionary process had allowed humans
to transcend mere physical existence, entering into the realm
of spiritual awareness. He expressed this view in yet another
important book, The Biology of Ultimate Concern (1967).
One of Dobzhansky’s most important contributions
to modern education is his insight that “nothing in biology
makes sense except in the light of evolution.” This is one of
the most often-quoted lines in modern biological education.
Everything from the components of the cell, to the structure
of genes, to the anatomy of the human body, to the function
of ecosystems, seems confusing when looked at from the
viewpoint of design by a Supreme Being (see intelligent
design) but makes sense only as the product of an evolutionary
process. Had Dobzhansky lived to see biology at the
beginning of the 21st century, he might have been astounded
at how correct his statement had proved to be (see DNA [evidence
for evolution]; ecology; eukaryotes, evolution
of; selfish genetic elements; noncoding DNA; symbiogenesis).
He died December 18, 1975.
Further Reading
Adams, M. B., ed. The Evolution of Theodosius Dobzhansky: Essays
on His Life and Thought in Russia and America. Princeton, N.J.:
Princeton University Press, 1994.
Ayala, Francisco J. “Theodosius Dobzhansky: A man for all seasons.”
Resonance, October 2000, 48–60.
Dobzhansky, Theodosius. “Nothing in biology makes sense except
in the light of evolution.” American Biology Teacher 35 (1973):
125–129.
Dubois, Eugène (1858–1940) Dutch Physician, Anthropologist
Marie Eugène François Thomas Dubois was the
discoverer of the original Java man specimens (see Homo
erectus). He was the first man to actually go looking for
fossils of human ancestors. Earlier discoveries of human
ancestors had been accidental (see Neandertals).
Born January 28, 1858, Dubois was a Dutch physician
who became passionately interested in the study of human
evolution. The only ancient human specimens that had been
found were Neandertals, and these were similar enough to
modern humans as to be classified in the same genus, Homo.
Dubois decided to find some more ancient ones. In 1887 he
set out for Sumatra. Early in the 19th century Buffon (see
Buffon, Georges) had speculated that Asia was where
humans originated, even though his theory was not evolutionary.
Sumatra was part of the Dutch territory in Indonesia,
so Dubois could travel there without difficulty.
Dubois joined a hospital staff and searched for fossils in
his spare time. His first two years produced no results, but
in 1889 he heard that a human-like fossil had been found on
the nearby island of Java. Excited, Dubois went to investigate,
only to find that the specimen was of a modern human.
He decided to remain and look for fossils himself on Java. He
established a camp near Trinil. In 1890 he found a molar and
a skullcap that had features that appeared to be intermediate
between apes and humans. In particular, the skullcap was
low and flat on top, having housed a small brain, and had