Ernst Mayr was a great naturalist and systematic ornithologist, known for contributing to the synthetic theory of evolution and for providing a definition of which species fit the idea of fertile hybridization.
He was familiar with the work of Charles Darwin and Theodosius Dobzhansky, which enabled him to give a genetic perspective to the theory of evolution.
Mayr fought for the recognition of biology as an autonomous science and independent from the rest of the natural sciences, proving that it was his long research career that spanned 80 years and resulted in numerous books and articles. Here we will see a summary of his life through a biography of Ernst Mayr.
- Related article: “Charles Darwin: biography of this famous English naturalist”
Brief biography of Ernst Mayr
Ernst Walter Mayr was born July 5, 1904 in Kempten, Bavaria, Germany, Being the second child 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, which he positively marked on the young Ernst Mayr.
Follow the family tradition studied medicine at the University of Greifswald and, after graduating in 1925, moved to Berlin to pursue a doctorate in ornithology., Diploma he obtained in 1926. In the German capital, he would also have the opportunity to study systematic biology.
His fondness for ornithology had long been embedded in him and, in fact, he published his first bird studies in 1923, while still studying medicine at Greifswald. The long excursions through the countryside with his father had allowed him to eagerly observe all kinds of birds typical of the German landscape, interested in their behavior, their ecological relations and the environment in which they lived.
After completing his training on German soil, Ernst Mayr had the opportunity to spend two years traveling the Pacific Islands, in particular New Guinea and the Solomon Islands. This was a scientific expedition during which research was carried out on endemic species of birds of Oceania, with the aim of discovering and establishing genetic and evolutionary laws.
Thanks to his observations during the Ernst Mayr expedition, the trip resembled that of Charles Darwin on the Beagle, he was fully convinced of the correctness of the evolutionary theory of the English naturalist. However, despite his conviction of Darwinist postulates, he doubted the possibility for individuals of the same species, at some point in their evolutionary history, to cease to be part of it and to give rise to two or more new and differentiated species. .
He then went to the United States to work at the New York Museum of Natural History, Where he researched the taxonomy of birds from 1931 to 1935. Shortly after, in 1937, he supported with other scientists the theory of “modern evolutionary synthesis, which had already been expounded in the book “Genetics and the Origin of Species” by Russian – American geneticist Theodosius Dobzhansky, a book which has played a crucial role in extending evolutionary postulates within the international scientific community.
From 1953 to 1975, he taught comparative zoology at Harvard University. In 1961, he became director of the Harvard Museum of Comparative Zoology. Shortly before entering this institution as a teacher, Mayr had proposed a new classification of fossils, Including those from hominids that had been documented so far. This alternative proposition came to be widely accepted within the paleontological community.
His wife was Margarete Mayr, who died in 1990, with whom he had two daughters. Ernst Walter Mayer died February 3, 2005 in Bedford, Massachusetts, United States, after a brief period of age-related illness. At the time of his death, he was 100 years old, half a year old at the age of 101, and had met five grandchildren and ten great grandchildren.
The biological concept of species
Through his detailed and systematic studies of birds in New Guinea, Melanesia and Polynesia, Ernst Mayr was able to describe 24 species that had never been documented before, in addition to 400 subspecies of birds. Thanks to what is observed on these islands and the knowledge of the works of Dobzhansky and Darwin, Mayr he developed his own theory on the origin of species, Taking many postulates of these evolutionists.
To understand how species are born, we must first understand what was the definition of species originally proposed by Mayr. For him, a species is a natural group or groups of individuals, in contact or not, which, if crossed by their individuals, result in fertile offspring in the vast majority of cases.
For example, a German Shepherd and a Chihuahua are the same species because when crossing we have fertile crossbreed dogs. On the other hand, a mule, a cross between a mare and a donkey, is sterile, which proves that the horse and the donkey are different species.
An Ernst Mayr the idea of allopatric speciation is attributed to him, Which has become the most 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 always the same, are isolated from each other due to natural barriers, such as mountains, a river, lying in different islands or geographic barriers that prevent the two populations from establishing reproductive contact.
Over the generations, combined with the appearance of mutations in both groups of individuals and also with the gradual adaptation to their environment, these reproductively isolated groups become more and more different. As time goes on, these two groups of individuals form two genetic lines so different that there comes a point when if two individuals crossbreed, one from each population, they will either have sterile offspring or, straight away. , they will not have children, that is to say that they are already two different species.
Although this idea of the emergence of new species is the most accepted in the scientific community, it has certain limitations. The first is that this species definition is not applicable to fossil organisms found up to this point and was also not applicable to asexually reproducing organisms. In addition, there are many cases of hybridization of two different species whose offspring have been shown to be fertile, as would be the case with the hybrid coydog, dog and coyote.
Mayr admitted that his original definition of species didn’t fit asexual organisms very well, but the idea of fertile hybridization led him to renew his concept of species. He paid particular attention to his original ideas of isolation mechanisms according to their function as biological properties of individuals which prevent the crossing of populations. These mechanisms do not always prevent occasional crosses, but they do prevent the complete fusion of two species.
To better understand this, imagine that two groups of individuals from the same species have evolved enough to be considered two different species, each with its own ecological niche. The geographic barrier between them may disappear, causing the two groups to make accidental reproductive contact. The isolation mechanisms of each of the two groups would make the probability that two individuals, one from each species, to have fertile offspring is nearly remote, but not impossible.
By means of these isolation mechanisms, although both groups returned to have contact and, even, interspecies copulation was common, there would be very few cases of fertile hybrids and there would even come a time when no matter how much they copulate, there would be no way to impregnate other people’s females. cash.
Faced with this situation, there would be two possible scenarios: one would be for the two species, which would have different food sources, to share the same habitat, while the other, in case of feeding on the same, would be that one. of the two species end up displacing or extinguishing the other.
Publications and commemorations
The point of Maximum Splendor in Ernst Mayr’s Life was the period between 1963 and 1970, corresponding to when he worked in Comparative Zoology at Harvard University. In those years publish several works on species, evolution and population genetics.
Among his most important books is “Systematics and the Origin of Species” (1942), in which he combines genetic Darwinism, clarifying what the English naturalist was unable to demonstrate due to the technological limitations of his time. , mainly the process of the origin of species. .
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 then published around 750 scientific papers and has received several honorary degrees from prestigious universities such as Oxford, Cambridge, Harvard, the Sorbonne, Uppsala and Berlin.
- Mayr, Ernst (1942). Systematics and the origin of species, from the point of view 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 birds in the region 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 diversity of life. Cambridge: Belknap Press of Harvard University Press. ISBN 978-0-674-27105-0.
- Mayr, Ernst. And William B. Provine, (eds) (1980). Evolutionary Synthesis: Perspectives on the Unification of Biology, ISBN 0-674-27225-0
- Mayr, Ernst (1982). The growth of biological thinking. Cambridge (Mass.): Belknap P. of Harvard UP ISBN 978-0-674-36446-2.