Ernst Mayr (born July 5, 1904) is one of the 20th century's leading evolutionary biologists. His work contributed to the conceptual revolution that led to the synthesis of Mendelian genetics and Darwinian evolution, and to the development of the biological species concept. His theory of allopatric speciation has become widely accepted as the standard mode of speciation, and is the basis of the theory of punctuated equilibrium. Furthermore, his writings reflect not only a technical expertise in biological subjects, but a broad and penetrating understanding of the deeper philosophical issues involved.
He was born in Kempten, Germany.
As a traditionally trained biologist with little mathematical experience, Mayr was often highly critical of early mathematical approaches to evolution such as those of J. B. S. Haldane, famously calling in 1959 such approaches "bean bag genetics". He continues to reject the view that evolution is the mere change of gene frequencies in populations, maintaining that other factors such as reproductive isolations have to be taken into acccount. In a similar fashion Mayr is also to this day quite critical of molecular evolutionary studies such as those of Carl Woese.
In many of his writings, Mayr has rejected reductionism in evolutionary biology, arguing that evolutionary pressures act on the whole organism, not on single genes, and that genes can have different effects depending on the other genes present. He advocates a study of the whole genome rather than only isolated genes.
Books by Ernst Mayr include: