Ernst Mayr

Ernst Walter Mayr (July 5, 1904, Kempten, Germany – February 3, 2005, Bedford, Massachusetts U.S.), was one of the 20th century's leading evolutionary biologists. He was also a renowned taxonomist, tropical explorer, ornithologist, historian of science, and naturalist. 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.

Mayr's theories on speciation remain the leading view of how new species evolve from common ancestors via Darwinian principles, and he provided the theoretical underpinning for the theory of punctuated equilibrium. Apart from biology, his prolific writings include influential works on the philosophy and history of science, and of biology in particular.

Mayr was an atheist, stating that "there is nothing that supports the idea of a personal God" (Shermer and Sulloway 2000).

Biography

1904 to 1930: Early life and expeditions in New Guinea and Pacific islands

Mayr was born in Kempten, Germany in 1904 and completed his high school education in Dresden. He planned to become a physician and undertook pre-clinical studies. However, he also was attracted to ornithology, the study of birds. Hull (1988) states that "officially he was enrolled as a medical student, but his true love was ornithology." Mayr was introduced to Erwin Stresemann, a well-known ornithologist at Berlin's Zoological Museum, as a result of Mayr's claimed sighting of red-crested pochards in Germany—a species that had not been seen in Europe for 77 years. After a tough interrogation, Stresemann accepted and published the sighting as authentic. Stresemann offered him a position with the Berlin Museum and the prospect of bird-collecting trips to the tropics on the condition that he completed his PhD studies in 16 months. Mayr completed his PhD in ornithology at the University of Berlin in June 1926 at the age of 21, while also completing (in 1925) his pre-clinical studies at medical school (Diamond 2001). Mayr then accepted the position offered to him at the Museum.

At the International Zoological Congress at Budapest in 1927, Mayr was introduced by Stresemann to banker and naturalist Walter Rothschild (Lord Rothschild's Museum), who asked him to undertake an expedition to New Guinea on behalf of himself and the American Museum of Natural History in New York. There was a desire to "clean up" the outstanding ornithological mysteries of New Guinea, by tracking all of the birds of paradise known only from specimens collected by natives and not yet traced to their home ground (Diamond 2001). In New Guinea, Mayr collected several thousands bird skins (he named 26 new bird species during his lifetime) and, in the process also named 38 new orchid species. Mayr did thorough bird surveys of New Guinea's five most important north coastal mountains. In the process, he was officially reported to have been killed by local tribes; survived severe cases of malaria, dengue, dysentry, and other diseases; and had a forced descent down a waterfall and nearly drowned in an overturned canoe (Diamond 2001). Nonetheless, he succeeded in his mission by reaching the summits of all five mountains and amassing large collections (Diamond 2001). None of the findings were the mysterious missing birds of paradise, leading Stresemann to conclude later that they were thus hybrids between known species (Diamond 2001).

During his stay in New Guinea, Mayr was invited to accompany the Whitney South Seas Expedition to the Solomon Islands. With this expedition, Mayr participated in surveys of birds in several islands in the Pacific.

1931 to 1975: Professional career as curator, professor, and author

Mayr received a telegram in 1930 to return to the American Museum of Natural History to identify the tens of thousans of birds specimens collected by the Whitney Expedition (Diamond 2001). In 1931, he accepted a curatorial position at the American Museum of Natural History, where he played the important role of brokering and acquiring the Walter Rothschild collection of bird skins, which was being sold in order to pay off a blackmailer, an unknown woman.

During his time at the museum, Mayr produced numerous publications on bird taxonomy, and in 1942, he published his first book, Systematics and the Origin of Species, a text that was renowed for completing the modern evolutionary synthesis.

After Mayr was appointed as curator at the American Museum of Natural History, he influenced American ornithological research by cultivating mentoring relationships with young birdwatchers. Mayr organized a monthly seminar under the auspices of the Linnaean Society of New York. This society, under the influence of J. A. Allen, Frank Chapman, and Jonathan Dwight concentrated on taxonomy and later became a clearing house for bird banding and sight records. There were a group of eight young birdwatchers from the Bronx and later became the Bronx County Bird Club, being led by Ludlow Griscom. Mayr was surprised at the differences between American and German Birding Societies. He noted that the German society was more scientific and concerned with life histories and reports on recent literature. Mayr also encouraged his Linnaean Society seminar participants to take up a specific research project of their own. One of Mayr's seminar participants was Joseph Hickey and under Mayr's influence went on to write A Guide to Birdwatching (1943). Hickey remembered later: "Mayr was our age and invited on all our field trips. The heckling of this German foreigner was tremendous, but he gave tit for tat, and any modern picture of Dr E. Mayr as a very formal person does not square with my memory of the 1930's. He held his own." Mayr's said of his own involvement with the local birdwatchers: "In those early years in New York when I was a stranger in a big city, it was the companionship and later friendship which I was offered in the Linnean Society that was the most important thing in my life."

Another person that Mayr greatly influenced was Margaret Morse Nice. Mayr encouraged her to correspond with the European ornithologists of the time, and helped her in her landmark study on Song Sparrows.

Mayr joined the faculty of Harvard University in 1953, where he also served as director of the Museum of Comparative Zoology from 1961 to 1970. He retired in 1975 as professor of zoology, showered with honors. He continued, however, for many years on the staff of the museum as professor emeritus.

1975 to 2005: Final 30 years of life, innumerable publications and awards

Following his retirement, Mary went on to publish more than 200 articles, in a variety of journals—more than some reputable scientists publish in their entire careers. Indeed, 14 of his 25 books were published after he was 65. Mayr was 97 years old when he published What Evolution is, and even as a centenarian, he continued to write books. On his 100th birthday, he was interviewed by Scientific American magazine.

Mayr received innumerable awards during his career, including the National Medal of Science, the Balzan Prize, the Sarton Medal of the History of Science Society, and the International Prize for Biology. In 1939, he was elected a Corresponding Member of the Royal Australasian Ornithologists Union. He was never awarded a Nobel Prize, but he noted that there is no Prize for evolutionary biology, and that Darwin would not have received one, either. Mayr did win a 1999 Crafoord Prize. That prize honors basic research in fields that do not qualify for Nobel Prizes and is administered by the same organization as the Nobel Prize.

Mayr was co-author of six global reviews of bird species new to science (listed below).

Mayr's ideas

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 maintained that factors such as speciation#reproductive isolation had to be taken into account. In a similar fashion, Mayr was also quite critical of molecular evolutionary studies such as those of Carl Woese.

In many of his writings, Mayr 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 advocated a study of the whole genome rather than of isolated genes only. Current molecular studies in evolution and speciation indicate that although allopatric speciation seems to be the norm in groups such as birds (possibly those groups with greater mobility), there are numerous cases suggestive of sympatric speciation in many invertebrates (especially in the insects).

Mayr was an outspoken defender of the scientific method, and one known to sharply critique science on the edge. As a notable recent example, he criticized the search for aliens as conducted by fellow Harvard professor Paul Horowitz as being a waste of university and student resources, for its inability to address and answer a scientific question.

Hull noted in 1988 that "Mayr was—and still is—an outgoing man who is very much at home at professional meetings and conferences, where he vigorously and tirelessly defends his views. He makes no distinctions between august experts and hesitant graduate students. He is as willing to spend time setting one straight as the other."

Modern synthesis

Between 1937 and 1947, neo-Darwinism or the modern evolutionary synthesis integrated Charles Darwin's theory of evolution by natural selection, Gregor Mendel's theory of genetics as the basis for biological inheritance, and mathematical population genetics. This was one of the most significant, overall developments in evolutionary biology since the time of Darwin. Bowler (1988) stated that there is "a sense in which the emergence of the modern synthetic theory can be seen as the first real triumph of Darwinism."

Essentially, neo-Darwinism introduced the connection between two important discoveries: the units of evolution (genes) with the mechanism of evolution (natural selection). By melding classical Darwinism with the rediscovered Mendelian genetics, Darwin's ideas were recast in terms of changes in allele frequencies. Neo-Darwinism thus fused two very different and formerly divided research traditions, the Darwinian naturalists and the experimental geneticists.

Mayr's 1942 work, Systematics and the Origin of Species, was one of the four canonical works of the modern evolutionary synthesis, joining those of G. G. Simpson (Tempo and Mode in Evolution), G. Ledyard Stebbins (Variation and Evolution in Plants), and Theodosius Dobzhansky (Genetics and the Origin of Species). Mayr himself places the key dates for the development of the synthesis between 1937, with Dobzhansky's work, and an international symposium at Princeton, New Jersey, January 2-4, 1947, which marked the formal completion of the synthesis (Hull 1988; Mayr 1982). The modern synthesis remains the prevailing paradigm of evolutionary biology.

Hull (1988) claimed that Mayr wrote his work "in white-hot indignation," in response to Richard Goldschmidt's The Material Basis of Evolution (1940).

"Species problem"

Charles Darwin's famous book "On the Origin of Species ..." presented an explanation for how species evolve and change over time. Although Darwin did not provide details on how a new species arises, he viewed speciation as a gradual process. If Darwin was correct, then when new incipient species are forming there must be a period of time when they are not yet distinct enough to be recognized as species. Darwin's theory suggested that there was often not going to be an objective fact of the matter, on whether there were one or two species.

Darwin's book triggered a crisis of uncertainty for some biologists over the objectivity of species, and some came to wonder whether individual species could be objectively real - i.e. have an existence that is independent of the observer.

While neither Darwin nor anyone else in his time knew the answer to the "species problem": how multiple species could evolve from a single common ancestor, Ernst Mayr approached the problem with a new definition for the concept 'species'.

Ernst Mayr's 1942 book was a turning point for the species problem . In it he wrote about how different investigators approach species identification, and he characterized these different approaches as different species concepts. 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 of organisms get isolated, the sub-populations will start to differ by genetic drift and natural selection over a period of time, and thereby evolve into new species. The most significant and rapid genetic reorganization occurs in extremely small populations that have been isolated.

Mary argued strongly for, what came to be called, a Biological Species Concept (BSC), which is that a species consists of populations of organisms that can reproduce with one another and that are reproductively isolated from other such populations. Mayr was not the first to define "species" on the basis of reproductive compatibility. Many others before Mayr had suggested this idea, as Mayr makes clear in his book on the history of biology . For example Mayr discusses how Buffon proposed this kind of definition of "species" in 1753. The idea of shared reproduction within species is even contained in the Biblical myth of Noah's ark, in which each species was preserved by saving a reproductive pair.

Theodosius Dobzhansky was a close contemporary of Mayr's and the author of a classic book, that came out a few years before Mayr's, that was about the evolutionary origins of reproductive barriers between species . Many biologists credit Dobzhansky and Mayr jointly for emphasizing the need to consider reproductive isolation when studying species and speciation .

After articulating the biological species concept in 1942, Mayr played a central role in the species problem debate over what was the best species concept. After Mayr's 1942 book many more species concepts were introduced. About two dozen species concepts have been identified or proposed since Mayr's 1942 book, and many articles and several books have been written on the species problem. Some, such as the Phylogenetic Species Concept (PSC), where designed to be more useful than the BSC for actually deciding when a new species should be described. However not all of the new species concepts were about identifying species, and some concepts were mostly conceptual or philosophical.

Mary staunchly defended the biological species concept against the many definitions of "species" that others proposed. Mayr was persuasive in many respects and from 1942 until his death in 2005 he and the biological species concept (BSC) played a central role in nearly all debates on the species problem. For many, the Biological Species Concept was a useful theoretical idea because it leads to a focus on the evolutionary origins of barriers to reproduction between species. But the BSC has been criticized for not being very useful, because it is not very much for deciding when to identify new species. It is also true that there are many cases where members of different species will hybridize and produce fertile offspring when they are under confined conditions, such as in zoos. One fairly extreme example is that lions and tigers will hybridize in captivity, and at least some of the offspring have been reported to be fertile. Mayr's response to cases like these is that the reproductive barriers that are important for species are the ones that occur in the wild. But even so it is also the case that there are many cases of different species that are known to hybridize and produce fertile offspring in nature.

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.

References

ISBN links support NWE through referral fees

• Bowler, P.J. 1988. The Non-Darwinian Revolution: Reinterpreting a Historical Myth. Baltimore, MD: The Johns Hopkins University Press.

• Diamond, J. M. 2001. Forward. In E. Mayr, What Evolution Is. New York: Basic Books. ISBN 0465044255.

• Dobzhansky, T. 1937. Genetics and the Origin of Species. New York, NY: Columbia University Press.

• Hull, D. L. 1988. Science as a Process: An Evolutionary Account of the Social and Conceptual Development of Science. Chicago: University of Chicago Press. ISBN 0226360504.

• Barrow, Mark V. 1998. A Passion for Birds: American Ornithology after Audubon. Princeton University Press. ISBN 0-691-04402-3
• Coyne, Jerry. 2005. Ernst Mayr (1904-2005). Science 307:1212-1213.
• Diamond, Jared. 2005. Obituary: Ernst Mayr (1904−2005). Nature 433:700-701.
• Milner, Richard. 1990. The Encyclopedia of Evolution Facts on File, New York. ISBN 0-8160-1472-8
• Schilthuizen, Menno. 2001. Frogs, Flies, and Dandelions: Speciation-The Evolution of New Species. Oxford ISBN 0-19-850393-8
• Kutschera, Ulrich. 2006. Dogma, not faith, is the barrier to scientific enquiry Nature 443, 26.

Bibliography

Books

• 1942 Systematics and the Origin of Species. Columbia University Press. New York. ISBN 0-674-86250-3 [one of the founding books of the neo-darwinian synthesis]
• 1963 Animal Species and Evolution. Harvard University Press. ISBN 0-674-03750-2 [another major evolutionary work]
• 1970 Populations, Species and Evolution. Harvard University Press. ISBN 0-674-69013-3
• 1976 Evolution and the Diversity of Life: Selected Essays. Harvard University Press. ISBN 0-674-27105-X
• 1982 The Growth of Biological Thought: Diversity, Evolution and Inheritance. Harvard University Press. ISBN 0-674-36446-5 [a major history of evolutionary thought]
• 1988 Toward a New Philosophy of Biology: Observations of an Evolutionist. Harvard University Press. ISBN 0-674-89666-1
• 1991 with P Ashlock Principles of Systematic Zoology revised ed. McGraw-Hill, NY. ISBN 0-07-041144-1
• 1991 One Long Argument: Charles Darwin and the Genesis of Modern Evolutionary Thought. Harvard University Press, Cambridge, Massachusetts. ISBN 0-674-63906-5
• 1997 This is Biology: The Science of the Living World. Harvard University Press. ISBN 0-674-88469-8
• 2001 with Jared Diamond. Birds of Northern Melanesia: Speciation, Ecology and Biogeography. Oxford University Press, NY. ISBN 0-19-514170-9
• 2001 What Evolution Is. Basic Books. New York. ISBN 0-465-04426-3 [excellent introductory account]
• 2004 What makes biology unique? Considerations on the Autonomy of a Scientific Discipline. Cambridge University Press. New York. ISBN 0-521-84114-3

Global reviews of species new to science

• Zimmer, J. T. & E. Mayr (1943) New species of birds described from 1938 to 1941 The Auk Vol. 60 pp. 249-262
• Mayr, E. (1957) New species of birds described from 1941 to 1955 Journal for Ornithology Vol. 98 pp. 22-35
• Mayr, E. (1971) New species of birds described from 1956 to 1965 Jour. f. Ornith. Vol. 112 pp. 302-316
• Mayr, E. & F. Vuilleumier (1983) New species of birds described from 1966 to 1975 Jour. f. Ornith. Vol. 124 pp. 217-232
• Vuilleumier, F. & E. Mayr (1987) New species of birds described from 1976 to 1980 Jour. f. Ornith. Vol. 128 pp. 137-150
• Vuilleumier, François, Mary LeCroy & Ernst Mayr (1992) New species of birds described from 1981 to 1990 Bulletin of the British Ornithologists' Club Vol. 112A pp. 267-309

Other notable publications

• 1923 "Die Kolbenente (Nyroca rufina) auf dem Durchzuge in Sachsen." Ornithologische Monatsberichte 31:135-136
• 1923 "Der Zwergfliegenschapper bei Greifswald." Ornithologische Monatsberichte 31:136
• 1926 "Die Ausbreitung des Girlitz (Serinus canaria serinus L.) Ein Beitrag zur Tiergeographie." J. fur Ornithologie 74:571-671
• 1927 "Die Schneefinken (Gattungen Montifringilla und Leucosticte)" J. für Ornithologie 75:596-619
• 1929 with W Meise. Zeitschriftenverzeichnis des Museums fur Naturkunde Mitteilungen aus dem Zoologischen Museum in Berlin 14:1-187
• 1930 (by Ernst Hartert) "List of birds collected by Ernst Mayr." Ornithologische Monatsberichte 36:27-128
• 1930 "My Dutch New Guinea Expedition." 1928. Ornithologische Monatsberichte 36:20-26
• 1931 Die Vogel des Saurwagedund Herzoggebirges (NO Neuginea) Mitteilungen aus dem Zoologischen Museum in Berlin 17:639-723
• 1931 "Birds collected during the Whitney South Sea Expedition. XII Notes on Halcyon chloris and some of its subspecies." American Museum Novitates no 469
• 1932 "A tenderfoot explorer in New Guinea" Natural History 32:83-97
• 1935 "Bernard Altum and the territory theory." Proceedings of the Linnaean Society of New York 45, 46:24-38
• 1940 "Speciation phenomena in birds." American Naturalist 74:249-278
• 1941 "Borders and subdivision of the Polynesian region as based on our knowledge of the distribution of birds." Proceedings of the 6th Pacific Scientific Congress 4:191-195
• 1941 "The origin and history of the bird fauna of Polynesia." Proceedings of the 6th Pacific Scientific Congress 4:197-216
• 1943 "A journey to the Solomons." Natural History 52:30-37,48
• 1944 "Wallace's Line in the light of recent zoogeographics studies." Quarterly Review of Biology 19:1-14
• 1944 "The birds of Timor and Sumba." Bulletin of the American Museum of Natural History 83:123-194
• 1944 "Timor and the colonization of Australia by birds." Emu 44:113-130
• 1946 "History of the North American bird fauna" Wilson Bulletin 58:3-41
• 1946 "The naturalist in Leidy's time and today." Proceedings of the Academy of Natural Sciences of Philadelphia 98:271-276
• 1947 "Ecological factors in speciation." Evolution 1:263-288
• 1948 "The new Sanford Hall." Natural History 57:248-254
• 1950 The role of the antennae in the mating behavior of female Drosophila. Evolution 4:149-154
• 1951 Introduction and Conclusion. Pages 85,255-258 in The problem of land connections across the South Atlantic with special reference to the Mesozoic. Bulletin of the American Museum of Natural History 99:79-258
• 1951 with Dean Amadon, "A classification of recent birds." American Museum Novitates no. 1496
• 1953 with E G Linsley and R L Usinger. Methods and Principles of Systematica Zoology. McGraw-Hill, New York.
• 1954 "Changes in genetic environment and evolution." Pages 157-180 in Evolution as a Process (J Huxley, A C Hardy and E B Ford Eds) Allen and Unwin. London
• 1955 "Karl Jordan's contribution to current concepts in systematics and evolution." Transactions of the Royal Entomological Society of London 107:45-66
• 1956 with C B Rosen. "Geographic variation and hybridization in populations of Bahama snails (Cerion)." American Museum Novitates no 1806.
• 1957 "Species concepts and definitions." Pages 371-388 in The Species Problem (E. Mayr ed). AAAS, Washington DC.
• 1959 "The emergence of evolutionary novelties." Pages 349-380 in The Evolution of Life: Evolution after Darwin, vol 1 (S. Tax, ed) University of Chicago.
• 1959 "Darwin and the evolutionary theory in Biology." Pages 1-10 in Evolution and Anthropology: A Centennial Appraisal (B J Meggers, Ed) The Anthropological Society of Washington, Washington DC.
• 1959 "Agassiz, Darwin, and Evolution." Harvard Library Bulletin. 13:165-194
• 1961 "Cause and effect in biology: Kinds of causes, predictability, and teleology are viewed by a practicing biologist." Science 134:1501-1506
• 1962 "Accident or design: The paradox of evolution." Pages 1-14 in The Evolution of Living Organisms (G W Leeper, Ed) Melbourne University Press.
• 1964 Introduction, Bibliography and Subject Pages vii-xxviii, 491-513 in On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life, by Charles Darwin. A Facsimile of the First Edition. Harvard University Press.
• 1965 Comments. In Proceedings of the Boston Colloguium for the Philosophy of Science, 1962-1964. Boston Studies in the Philosophy of Science 2:151-156
• 1969 Discussion: Footnotes on the philosophy of biology. Philosophy of Science 36:197-202
• 1972 Continental drift and the history of the Australian bird fauna. Emu 72:26-28
• 1972 Geography and ecology as faunal determinants. Pages 549-561 in Proceedings XVth International Ornithological Congress (K H Voous, Ed) E J Brill, Leiden, The Netherlands.
• 1972 Lamarck revisited. Journal of the History of Biology. 5:55-94
• 1974 Teleological and teleonomic: A new analysis. Boston studies in the Philosophy of Science 14:91-117
• 1978 Tenure: A sacred cow? Science 199:1293
• 1980 How I became a Darwinian, Pages 413-423 in The Evolutionary Synthesis (E Mayr and W Provine, Eds) Harvard University Press, Cambridge, Massachusetts.
• 1980 with W B Provine, Eds. The Evolutionary Synthesis. Harvard University Press.
• 1981 Evolutionary biology. Pages 147-162 in The Joys of Research (W. Shripshire Jr, Ed.) Smithsonian Institution Press.
• 1984 Evolution and ethics. Pages 35-46 in Darwin, Mars and Freud: Their influence on Moral Theory (A L Caplan and B Jennings, Eds.) Plenum Press, New York.
• 1985. Darwin's five theories of evolution. In D. Kohn, ed., The Darwinian Heritage, Princeton NJ: Princeton University Press, pp. 755-772.
• 1985. How biology differs from the physical sciences. In D. J. Depew and B H Weber, eds., Evolution at a Crossroads: The New Biology and the New Philosophy of Science, Cambridge MA: The MIT Press, pp. 43-63.
• 1988. The why and how of species. Biology and Philosophy 3:431-441
• 1992. The idea of teleology. Journal of the History of Ideas 53:117-135
• 1994. with W.J. Bock. Provisional classifications v. standard avian sequences: heurisitics and communication in ornithology. Ibis 136:12-18
• 1996. What is a species, and what is not? Philosophy of Science 63 (June): 262-277.
• 1996. The autonomy of biology: the position of biology among the sciences. Quarterly Review of Biology 71:97-106
• 1997. The objects of selection Proc. Natl. Acad. Sci. USA 94 (March): 2091-94.
• 1999. Darwin's influence on modern thought Crafoord Prize lecture, September 23, 1999.
• 2000. Biology in the Twenty-First Century Bioscience 50 (Oct. 2000): 895-897.
• 2001. The philosophical foundations of Darwinism Proceedings of the American Philosophical Society 145:488-495
• 2002. with Walter J Bock. Classifications and other ordering systems. Zeitschrift Zool. Syst. Evolut-Forsch. 40:1-25

External links

• "80 Years of Watching the Evolutionary Scenery" - by Ernst Mayr, Science.
• Mayr on Eldredge and Gould's punctuated equilibria.
• Ernst Mayr obituary in the Times
• Ernst Mayr obituary in the Economist
• Ernst Mayr and the Evolutionary Synthesis

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