Ornithology, Evolution, and Philosophy 123

30 1 Childhood and Youth
The three-volume magnum opus of the renowned ornithologist Ernst Hartert on
the birds of the Palearctic fauna (1903–1922) had just been completed. However,
Hartert was mainly a practical taxonomist. The above letter of the 19-year-old
Ernst Mayr shows his early interest in theoretical analyses of taxonomic data
and his ability to synthesize critically the results derived from studies in widely
different fields, capacities which characterize many of his publications in later
decades. It is evident that already in the spring of 1924 he was familiar not only
with writings of the leading ornithologists Stresemann, Hartert, Kleinschmidt,
etc., but also with the basic concepts of evolution, genetics and systematics through
a close reading of textbooks and specialized articles, as shown by his reference to
Erwin Baur’s “modifications” and the theory of inheritance of acquired characters.
His concern with genetics probably goes back to the volume on human heredity
(Menschliche Erblichkeitslehre, 1923) by E. Baur, E. Fischer and F. Lenz which
greatly impressed the student in Greifswald (notebook). Mayr’s course in genetics
was rather traditional consisting largely in exercises demonstrating the “Mendelian
Laws”; the emphasis was on mutation and physiological genetics. The connection
between genetics and evolution was not dealt with at all.
Heavily occupied with the manuscript for his large volume on Aves and many
other projects, Stresemann was not able to follow up on Mayr’s suggestions. However,
he was so much impressed by his enthusiasm and knowledge that he wrote
to his fatherly friend Ernst Hartert a few weeks later (12 July 1924):
“I have discovered […] a rising star, a young Studiosus med[icinae] by the rare
name of Mayr, of fabulous systematic instinct. Unfortunately, he will probably have
to wither away as a medical doctor. If only one could always place the right man in
the right position!” (transl.)
At this moment, neither Stresemann nor Hartert could have imagined that this
young man, less than 8 years hence, would be proposed to be Hartert’s successor
at Lord Walter Rothschild’s private museum in Tring (see p. 96, footnote) and
actually became the curator of the Rothschild Collection at the American Museum
of Natural History.
In 1925, Mayr entered the following remarks into his notebook:
“Theses regarding the dispute between Darwinism and Lamarckism.
1. The controversy in evolutionary theory today does not concern the question
of selection. Selection is also acknowledged by the Lamarckian.
2. The controversy relates to the cause of variability (which Darwin accepts as
given).
3. Varieties [heritable] originate according to De Vries by random mutations. The
mode of life of an organism is determined by the structures thus originating.
This seems to be the view of some evolutionists, particularly of experimental
zoologists and geneticists.
4. The Lamarckian, on the other hand, claims that new variants originate under
the influence of the mode of life [Lamarck] or of the environment [Geoffroy].
5. The Lamarckian has the right to interpret the laws and findings of genetics in
his sense; this refers both to mutations and Dauermodifications; cumulative
aftereffect–Alverdes.