Ernst Mayr: biography of this evolutionary biologist

This was the life of Ernst Mayr, one of the most influential biologists and naturalists in history.

Ernst Mayr was a great systematic naturalist and ornithologist, known to have contributed to the synthetic theory of evolution and to have given a definition of what species are that fits the idea of fertile hybridization.

He was a great connoisseur of the work of Charles Darwin and Theodosius Dobzhansky, which allowed him to give a genetic perspective to the evolutionary theory.

Mayr fought for the recognition of biology as an autonomous science, independent from the rest of the natural sciences, demonstrating it in his extensive research career that lasted for 80 years and resulted in numerous books and articles. Here we will take a look at a summary of his life through a biography by Ernst Mayr.

Short biography of Ernst Mayr

Ernst Walter Mayr was born on July 5, 1904 in Kempten, Bavaria, Germany, the second son of Dr. Otto Mayr and Helene Pusinelli.He was the second son of the marriage between Dr. Otto Mayr and Helene Pusinelli. In his family there was always a great interest in nature and Dr. Mayr used to take his children to the countryside to observe nature, something that had a positive influence on the young Ernst Mayr.

Following the family tradition He studied medicine at the University of Greifswald and, after graduating in 1925, left for Berlin to pursue a doctorate in ornithology, which he obtained in 1926.D. in Ornithology, which he obtained in 1926. In the German capital he also had the opportunity to study Systematic Biology.

His love for ornithology had already been nesting in him for some time and, in fact, he published his first studies on birds in 1923, when he was still studying medicine in Greifswald. Long excursions in the countryside with his father had served him to avidly observe all kinds of birds typical of the German landscape, becoming interested in their behavior, ecological relationships and the environment in which they lived.

After completing his training in Germany, Ernst Mayr had the opportunity to spend two years in Germany to observe birds of the German landscape. had the opportunity to spend two years traveling in the Pacific islands, especially New Guinea and the Solomon Islands.. It was a scientific expedition, in which he was investigating and relating endemic species of birds of Oceania, with the intention of finding and establishing genetic and evolutionary laws.

Thanks to his observations during the expedition, Ernst Mayr, whose voyage resembled Charles Darwin's aboard the Beagle, was fully convinced of the correctness of the English naturalist's evolutionary theory. However, despite his conviction with the Darwinist postulates, he had doubts about how it was possible that individuals of the same species, at some point in their evolutionary history, ceased to be part of the same species and gave rise to two or more new and differentiated species.

Later he went to the United States to work at the Museum of Natural History in New York, where he did research in taxonomy.where he did research in bird taxonomy from 1931 to 1935. Shortly thereafter, in 1937, he along with other scientists gave support to the theory of the "modern evolutionary synthesis", which had already been outlined in the book "Genetics and the Origin of Species" by the Russian-American geneticist Theodosius Dobzhansky, a book that was crucial in spreading evolutionary postulates within the international scientific community.

From 1953 to 1975 he taught Comparative Zoology at Harvard University. In 1961 he became the director of the Harvard Museum of Comparative Zoology. Shortly before joining that institution as a docent, Mayr had proposed a new classification for fossils. had proposed a new classification for fossilsincluding those of the hominids that had been documented up to that time. This alternative proposal eventually gained wide acceptance within the paleontological community.

His wife was Margarete Mayr, who died in 1990, with whom he had two daughters. Ernst Walter Mayer died on February 3, 2005, in Bedford, MassachusettsUnited States, after a brief period of age-related illness. At the time of his death he was 100 years old, half a year shy of his 101st birthday and having known five grandchildren and ten great-grandchildren.

The Biological concept of species

Thanks to his detailed and systematic studies on the birds of New Guinea, Melanesia and Polynesia, Ernst Mayr managed to describe 24 species that had never been documented before, as well as 400 subspecies of birds. Thanks to what he observed in these islands and knowing the works of Dobzhansky and Darwin, Mayr elaborated his own theory on the origin of the species, taking many postulates of those evolutionarytaking many of the postulates of these evolutionists.

To understand how species arise, we must first understand what was Mayr's original definition of species. For him, a species is a natural group or groups of individuals, which may or may not be in contact with each other, which, if their individuals interbreed, result in fertile offspring in the vast majority of cases.

For example, a German Shepherd and a Chihuahua are of the same species because, by crossing them, we have fertile mongrel dogs. On the other hand, a mule, a cross between a mare and a donkey, is sterile, proving that the horse and the donkey are different species.

Ernst Mayr is credited with the idea of allopatric speciationwhich has become the most widely accepted mechanism for understanding the emergence of a new species. According to this idea, species arise when two or more groups of individuals of the same species, although still the same, are isolated from each other because of natural barriers, such as mountains, a river, being on different islands or any geographical impediment that prevents the two populations from establishing reproductive contact.

As generations go by, combined with the appearance of mutations in both groups of individuals and, also, the progressive adaptation to their environments, these reproductively isolated groups become more and more different. As time goes on, these two groups of individuals constitute two genetic lineages so different that there comes a time when if two individuals interbreed, one from each population, they will either have sterile offspring or, directly, they will not have a child, meaning that they are already two different species.

Although this idea of how new species arise is the most accepted in the scientific community, it has certain limitations. The first is that this definition of species is not applicable to the fossil organisms found up to that time, nor was it found up to that time, nor was it applicable to organisms that reproduce asexually. In addition, there are many cases of hybridization of two different species whose offspring have turned out to be fertile, as would be the case of the coydog, a hybrid of dog and coyote.

Mayr admitted that his original definition of species does not fit asexual organisms very well, but the idea of fertile hybridization led him to renew his concept of species. He paid special attention to his original ideas of isolation mechanisms in terms of their function as biological properties of individuals that prevent interbreeding of populations.. These mechanisms do not always prevent occasional interbreeding, but they would prevent the complete merger of two species.

To understand this better, let us imagine that two groups of individuals originally of the same species have evolved sufficiently to be considered two distinct species, each with its own ecological niche. It may be the case that the geographic barrier that separated them disappears, allowing the two groups to establish accidental reproductive contact. The isolation mechanisms of each of the two groups would make the probability of two individuals, one of each species, having fertile offspring almost remote, although not impossible.

By means of these isolation mechanisms, even if both groups were to have contact again and even if interspecific copulation were frequent, there would be very few cases of fertile hybrids. and there would even come a time when no matter how much they copulated, there would be no way to fertilize the females of the other species.

In this situation there would be two possible scenarios: one would be that both species, which would have different food sources, would share the same habitat, while the other, in the case of feeding on the same food, would be that one of the two species would end up displacing or extinguishing the other.

Publications and commemorations

The peak of Ernst Mayr's life was the period between 1963 and 1970, when he was working in Comparative Zoology at Harvard University. During these years published several books on species, evolution and population genetics..

Among his most important books we find "Systematics and the Origin of Species" (1942), in which he combines genetic Darwinism, clarifying what the English naturalist could not demonstrate because of the technological limitations of his time, mainly the process of how species originate.

Other of his most important works are:

• "Animal Species and Evolution" (1963).
• "Principles of Systematic Zoology" (1980).
• "Growth of Biological Thought" (1982).
• "This Is Biology" (1997)

Throughout his career he published some 750 scientific articles y recibió varios títulos honoríficos de universidades prestigiosas como Oxford, Cambridge, Harvard, La Sorbona, Uppsala, y Berlín.

Referencias bibliográficas:

• Mayr, Ernst (1942). Systematics and the Origin of Species, from the Viewpoint of a Zoologist. Cambridge: Harvard University Press. ISBN 978-0-674-86250-0.
• Mayr, Ernst (1945). Birds of the Southwest Pacific: A Field Guide to the Birds of the Area Between Samoa, New Caledonia, and Micronesia. New York: Macmillan.
• Mayr, Ernst (1963). Animal Species and Evolution. Cambridge: Belknap Press of Harvard University Press. ISBN 978-0-674-03750-2.
• Mayr, Ernst (1970). Populations, Species, and Evolution. Cambridge: Belknap Press of Harvard University Press. ISBN 978-0-674-69013-4.
• Mayr, Ernst (1976). Evolution and the Diversity of Life. Cambridge: Belknap Press of Harvard University Press. ISBN 978-0-674-27105-0.
• Mayr, Ernst. & William B. Provine, (eds) (1980). The Evolutionary Synthesis: Perspectives on the Unification of Biology, ISBN 0-674-27225-0
• Mayr, Ernst (1982). The Growth of Biological Thought. Cambridge (Mass.): Belknap P. of Harvard U.P. ISBN 978-0-674-36446-2.