Ernst Mayr

Ernst Mayr bigraphy, stories - German-American evolutionary biologist

Ernst Mayr : biography

July 5, 1904 – February 3, 2005

Not to be confused with Ernst Mayer, Ernst Meyer or Ernest May.

Ernst Walter Mayr (July 5, 1904 – February 3, 2005) was one of the 20th century’s leading evolutionary biologists. He was also a renowned taxonomist, tropical explorer, ornithologist, and historian of science.Rennie, J. (1994) Profile: Ernst Mayr – Darwin’s Current Bulldog, Scientific American 271(2), 24-25. His work contributed to the conceptual revolution that led to the modern evolutionary synthesis of Mendelian genetics, systematics, and Darwinian evolution, and to the development of the biological species concept.

Although Charles Darwin and others posited that multiple species could evolve from a single common ancestor, the mechanism by which this occurred was not understood, creating the species problem. Ernst Mayr approached the problem with a new definition for the concept of species. In his book Systematics and the Origin of Species (1942) he wrote that a species is not just a group of morphologically similar individuals, but a group that can breed only among themselves, excluding all others. When populations within a species become isolated by geography, feeding strategy, mate selection, or other means, they may start to differ from other populations through genetic drift and natural selection, and over time may evolve into new species. The most significant and rapid genetic reorganization occurs in extremely small populations that have been isolated (as on islands).

His theory of peripatric speciation (a more precise form of allopatric speciation which he advanced), based on his work on birds, is still considered a leading mode of speciation, and was the theoretical underpinning for the theory of punctuated equilibrium, proposed by Niles Eldredge and Stephen Jay Gould. Mayr is sometimes credited with inventing modern philosophy of biology, particularly the part related to evolutionary biology, which he distinguished from physics due to its introduction of (natural) history into science.


Mayr was the second son of Helene Pusinelli and Dr. Otto Mayr. His father was a jurist (District Prosecuting Attorney at Würzburg)Haffer 2007:12 but took an interest in natural history and took the children out on field trips. He learnt all the local birds in Würzburg from his elder brother Otto. He also had access to a natural history magazine for amateurs, Kosmos. His father died just before he was thirteen. The family then moved to Dresden and he studied at the Staatsgymnasium (“Royal Gymnasium” until 1918) in Dresden-Neustadt and completed his high school education there. In April 1922, while still in high school, he joined the newly founded Saxony Ornithologists’ Association. Here he met Rudolf Zimmermann, who became his ornithological mentor. In February 1923, Mayr passed his high school examination (Abitur) and his mother rewarded him with a pair of binoculars.Haffer 2007:22

On March 23, 1923 on the lakes of Moritzburg, the Frauenteich, he spotted what he identified as a Red-crested Pochard. The species had not been seen in Saxony since 1845 and the local club argued about the identity. Raimund Schelcher (1891–1979) of the club then suggested that Mayr visit his classmate Erwin Stresemann on his way to Greifswald, where Mayr was to begin his medical studies. After a tough interrogation, Stresemann accepted and published the sighting as authentic. Stresemann was very impressed and suggested that, between semesters, Mayr could work as a volunteer in the ornithological section of the museum. Mayr wrote about this event, "It was as if someone had given me the key to heaven." He entered the University of Greifswald in 1923 and, according to Mayr himself, "took the medical curriculum (to satisfy a family tradition)."Mayr & Provine, 1998:p. 413 Mayr was endlessly interested in ornithology and "chose Greifswald at the Baltic for my studies for no other reason than that…it was situated in the ornithologically most interesting area." Although he ostensibly planned to become a physician, he was "first and foremost an ornithologist." During the first semester break Stresemann gave him a test to identify treecreepers and Mayr was able to identify most of the specimens correctly. Stresemann declared that Mayr ‘was a born systematist’.Haffer 2007:23 In 1925 Stresemann suggested that he give up his medical studies and join the Berlin Museum with the prospect of bird-collecting trips to the tropics on the condition that he completed his doctoral studies in 16 months. Mayr completed his doctorate in ornithology at the University of Berlin under Dr. Carl Zimmer, who was a full professor (Ordentlicher Professor), on June 24, 1926 at the age of 21. On July 1 he accepted the position offered to him at the Museum for a monthly salary of 330.54 Reichsmark.Haffer 2007:35