Extinction of Species

Extinction of Species


(of plants, animals, microorganisms), a phenomenon that occurs during the process of development of living nature during the earth’s geological history. Extinction of organic forms takes place as a result of natural selection in the presence of essential changes in the external environment in those instances when organisms do not have time to adapt to these changes or when even insignificant changes in the conditions of existence lead to a hindrance of the species’ propagation. Thus, extinction is an important part of the evolution of living nature.

The history of the organic world shows that an enormous number of forms have become extinct. G. Cuvier and his followers tried to explain extinction by the theory of catastrophes. Refuting this theory, J. B. Lamarck asserted that all species that had disappeared had not become extinct but had been regenerated into new ones. In the beginning of the 19th century, the Italian paleontologist G. Brocchi mistakenly supposed that species, like individuals, have a definite life expectancy and die upon reaching a known “age.” Other hypotheses attempted to explain extinction by a change of some single factor in the environment—for example, a general cooling or warming of the climate or a strengthening or weakening of solar radiation.

Only Darwinism explains extinction in accordance with the facts of the history of the organic world. C. Darwin showed that the extinction of organic forms is caused by changes in the surrounding environment, during which not only changes of the abiotic factors of the external environment (those pertaining to the inorganic world) have enormous significance, but so do biotic factors (interspecies relations). A rapid change of environment can be a direct cause of the extinction of species occupying a limited land or water territory. Forms and groups of forms that are widely distributed (such as those living simultaneously in all the oceans or on a majority of the earth’s continents) do not become extinct everywhere. The final extinction of certain species is often prolonged, so that they can be preserved in limited regions because of local favorable conditions (usually biotic). The existence of relict forms is connected with this process. V. O. Kovalevskii developed and extended the Darwinian concept of extinction on the basis of paleontological facts by showing that one of the most important conditions for extinction is inadaptive evolution.

In connection with swift technical progress and the continual growth of population, one of the most important biotic factors that directly or indirectly condition the extinction of many species is the activity of man.


Darwin, C. Soch., vol. 3. Moscow-Leningrad, 1939.
Davitashvili, L. Sh. Istoriia evoliutsionnoi paleontologii ot Darvina do nashikh dnei. Moscow-Leningrad, 1948.
Davitashvili, L. Sh. Prichiny vymiraniiaorganizmov. Moscow, 1969.
Axelrod, D. I. Quaternary Extinctions of Large Mammals. Berkeley-Los Angeles, 1967.


References in periodicals archive ?
The extinction of species by human activity continues to accelerate, fast enough to eliminate more than half of all species by the end of this century.
Mr William Symes, a PhD student from the Department of Biological Sciences at the NUS Faculty of Science, who led the study, said, Increasing our understanding of the drivers of international wildlife trade is critical as unsustainable harvesting of wildlife can lead to population decline and the extinction of species.
Chester Zoo in the Wild: How the Zoo is working in the field to prevent extinction of species around the world, takes place this evening, on the university's Parkgate Road Campus, in the Binks Building, Room CBK 107.
Exceeding this threshold will lead to the sixth mass extinction of species on Earth, LIFE said, quoted by BTA.
Hurricanes, earthquakes, pollution, extinction of species, droughts, all this is a product of the capitalist model and industrialization," he said.
These conditions last for several years, would have caused a collapse of the global food chain, and would have contributed to the extinction of species that survived the immediate effects of the asteroid impact," the study says.
He explains that environmental degradation, the extinction of species, pollution, war, and failing public institutions are all reflections of our relationships with ourselves.
According to the promotional material for Half Earth, Wilson argues that, "In order to stave off the mass extinction of species, including our own, we must move swiftly to preserve the biodiversity of our planet.
The extinction of species alerts us about the future coming problems to our motherland Earth.
The fungus has led to the widespread demise of amphibian populations and the extinction of species.
Humans are the agent behind such factors that affecting water supply food supply pollution extinction of species and climate change(Pokhriyal et al.
He said that Natural Disasters have caused the extinction of species in the past and man-made calamity act as a trigger to the disasters for such extinctions.