Gerhard Heilmann

Heilmann lacked a formal training in science although he studied medicine briefly before shifting to art.

The English edition however reached out to a much larger audience and influenced ideas in bird evolution for nearly half a century.

Against the wishes of his family, he quit his medicine studies in 1883 and became an apprentice painter of Franz Schwartz and later P S Krøyer.

In later life he rebelled against religion and in 1940 he wrote a book on Darwinism and devoted the last section to arguing against religious ideas (Univers og traditionen).

[5] Like Thomas Huxley, Heilmann compared Archaeopteryx and other birds to an exhaustive list of prehistoric reptiles, and also came to the conclusion that theropod dinosaurs like Compsognathus were the most similar.

[5] Heilmann's extremely thorough approach ensured that his book became a classic in the field and its conclusions on bird origins, as with most other topics, were accepted by nearly all evolutionary biologists for the next four decades,[7] despite the discovery of clavicles in the primitive theropod Segisaurus in 1936.

Winge's short responses to an eight-page letter of queries and ideas caused much irritation and Heilmann decided to stop writing to him.

It must have been rough on you – who must know birds well, and as a medical doctor must possess some general sense of natural history – to include in the journal the dilettantish mess which occupies most of the issue.

His first paper published in the Danish ornithology journal was however discovered by American paleontologist R. W. Shufeldt, who was able to make sense of it thanks to help from his Norwegian wife.

[3] In 1940, Heilmann published a second book on Darwinian evolution, the Univers og traditionen (Universe and Tradition, in Danish).