3 The New York Years (1931–1953)

History of Biology 341
plan, however, did not materialize. He took the topic of territory up again in New
York when, during the early 1930s, he cooperated with young field ornithologists,
members of the Linnaean Society (see p. 109). In conjunction with this work
he wrote his first strictly historical article on “Bernard Altum and the territory
theory” (1935c). In 1868, Altum had clearly recognized that many male birds set up
a territory which they defend against conspecific males (this, incidentally, had been
established independently already by Aristotle, by Adam von Pernau in Germany
during the early 18th century and was again discovered by British ornithologists
during the early 20th century).
Early historical studies. When in 1946 the Academy of Natural Sciences of Philadelphia
awarded Mayr the Leidy medal for his book Systematics and the Origin of
Species (1942e) he compared, in his acceptance speech, the activities of the naturalists
of the 19th and 20th centuries. Hundred years ago natural history was largely
descriptive and analytical, he said, building a vast store of facts. Today, increasingly
often “How?” and “Why?” questions are being asked and naturalists attempt
to interpret the gathered facts and to correlate them with those from neighboring
sciences like zoogeography, ecology, genetics, and ethology. Mayr here spoke for
the first time of the “non-dimensional species” of the naturalist, non-interbreeding
entities in a local area (in sympatry) and at a single time level, and called attention
to the conceptual shift from the typological (morphological) to the biological
species concept. Species (taxa) are two-dimensional and often polytypic (species
and subspecies). Allopatric forms are difficult to handle taxonomically but have
helped to solve the problem of geographical speciation.
Mayr’s (1954i) review of W. Zimmermann’s book, History of Evolution (1953)
is intriguing because he outlined here how a history of the modern evolutionary
synthesisoughttobewrittenandgave,sotospeak,ablueprintofhislaterhistorical
handbook (1982d). At the same time he stated why he thought that the evolutionary
synthesis was truly a synthesis:
“If I were to write a history of this field, I would try to show how growing maturity
in the contributing fields eventually permitted this synthesis. After an introductory
chapter devoted to the period before Darwin, I would try to demonstrate how the
publication of the Origin of Species stimulated an unprecedented amount of fact
searching and theory building in biology. […] Nearly every theory was partly
right, and partly wrong, and, by discarding the ‘wrong’ parts, it became possible
to synthesize the theory that is now almost universally held among evolutionists.”
Many historical aspects of the study of individual and geographical variation
in animals are discussed in conjunction with his book projects (1942e, 1953a,
1963b). A penetrating analysis followed of the theoretical views on biological
species and speciation of the entomologist Karl Jordan (1861–1959) who, around
the turn of the 20th century, discussed the gist of the new or population systematics
and, with Edward Poulton (1856–1943), promoted the biological species concept
and geographical speciation (Mayr 1955e, 1990g). This article on the work of
K. Jordan (and E. Poulton) was one of Mayr’s earliest attempts to point out how great
a contribution systematists had made (see also Mayr 1973i) to the evolutionary