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Ivan Schmalhausen

Ivan Schmalhausen is a biology topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Ivan Schmalhausen rather than just read about it. In short: Ivan Ivanovich Schmalhausen (Russian: Ива́н Ива́нович Шмальга́узен; 23 April 1884 – 7 October 1963) was a Russian and Soviet zoologist and evolutionary biologist of German descent. He developed the theory of stabilizing selection, and took part in the development of the modern evolutionary synthesis.

Key takeaways

  • Ivan Schmalhausen belongs to biology; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Ivan Schmalhausen to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Ivan Schmalhausen from memory before moving on to harder problems.

Reference excerpt

Ivan Ivanovich Schmalhausen (Russian: Ива́н Ива́нович Шмальга́узен; 23 April 1884 – 7 October 1963) was a Russian and Soviet zoologist and evolutionary biologist of German descent. He developed the theory of stabilizing selection, and took part in the development of the modern evolutionary synthesis. He is remembered, among other things, for Schmalhausen's law, which states that a population at its limit of tolerance in one aspect is vulnerable to small differences in any other aspect.

Early life and education Ivan Ivanovich Schmalhausen was born in Kiev, Russian Empire (now Ukraine) on April 23, 1884, to Luise Schmalhausen (Luisa Ludwigovna Schmalhausen) and Johannes Schmalhausen (also transliterated as Ivan Fedorovich Schmalhausen, Иван Фёдорович Шмальгаузен). His father was one of the founders of Russian paleobotany. In 1901, Schmalhausen graduated from the First Kiev Gymnasium and enrolled at Kiev University, but was expelled a year later after taking a part in student disturbances. In 1902 he resumed his university studies at Kiev in the faculty of biological science. Around 1902 he became acquainted with the founder of the Russian school of evolutionary morphology, Alexey Severtsov (1866–1936). In 1904, Schmalhausen, under the guidance of Severtsov, completed his first scientific work on the embryonic development of lungs in the grass snake. He graduated from the university in 1909. In 1910, he married Lydia Kozlova, a French language teacher at Kiev Women Gymnasium.

Career In 1912 Schmalhausen became a professor of zoology in Kiev University. From 1920–1930 he was head of the Department of Vertebrate Zoology. During 1930–1941 Schmalhausen was director of Institute of Zoology in Kiev, at the same during 1936–1948 he was director of Institute of Evolutionary Morphology in Moscow and during 1939–1948 - also a head to the Department of Darwinism in Moscow University. The Institute of Zoology in Kiev was later named in his honour the I. I. Schmalhausen Institute of Zoology. He published his most well known book, Faktory Evolyutsii in 1946. This was translated into English by Isadore Dordick and edited by Theodosius Dobzhansky. This translation appeared as Factors of Evolution: The Theory of Stabilizing Selection in 1949. On 23 August 1948, after the August 1948 Session of VASKhNIL, he became victim of order 1208, one of a series signed by Minister of Higher Education in the USSR, Sergei Kaftanov, which led to the mass dismissals of many university professors. This destroyed his career, as it removed his professorship and also decreed the destruction of his books and research projects. This action came about due to accusations of Weismannism and pro-Morganism, and of promoting the neo-Darwinian theory of evolution by natural selection, at a time when Trofim Lysenko and his followers were emphasising a process of heredity that focused on interaction with the environment and the inheritance of acquired characteristics along Lamarckian lines. (Lysenko put his theory into practice in agriculture, claiming to have improved wheat using Lamarckian techniques. Lysenkoism played a major role in Stalin's politics, stressing that hard work led to improvement in future generations.) During these events in 1948 Schmalhausen was removed from the heading positions in Moscow institutions, Institute of Evolutionary Morphology and Department of Darwinism of Moscow University. Until the end of his life he worked in the Zoological Institute in Leningrad as a common senior researcher. In 1955, Schmalhausen was one of the signatories of the "Letter of 300"—a collective letter by 300 scientists denouncing Lysenkoism. He died on October 7, 1963, in Leningrad.

Schmalhausen's law

Schmalhausen's law is a general principle that a population living at the boundary of its tolerance, in extreme or unusual conditions with regard to any aspect of its existence will be more vulnerable to small differences in any other aspect. Therefore, the variance of data is not simply noise interfering with the detection of so-called "main effects", but also an indicator of stressful conditions leading to greater vulnerability.

References

Worked examples

Example 1 — a first encounter with Ivan Schmalhausen

Start with the simplest possible case. Write down what Ivan Schmalhausen claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Ivan Schmalhausen before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Ivan Schmalhausen ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Ivan Schmalhausen

In research
Ivan Schmalhausen appears in biology research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Ivan Schmalhausen in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Ivan Schmalhausen is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1884 births, 1963 deaths, 20th-century Russian scientists, so understanding it makes those chapters shorter.
In everyday life
Look for Ivan Schmalhausen outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.
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How to study Ivan Schmalhausen in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Ivan Schmalhausen means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Ivan Schmalhausen out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Ivan Schmalhausen in simple terms?

Ivan Ivanovich Schmalhausen (Russian: Ива́н Ива́нович Шмальга́узен; 23 April 1884 – 7 October 1963) was a Russian and Soviet zoologist and evolutionary biologist of German descent. He developed the theory of stabilizing selection, and took part in the development of the modern evolutionary synthesi…

Why does Ivan Schmalhausen matter?

Because it connects several biology ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Ivan Schmalhausen?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Ivan Schmalhausen.

Tags

  • 1884 births
  • 1963 deaths
  • 20th-century Russian scientists
  • 20th-century Ukrainian zoologists
  • Evolutionary biologists
  • Full Members of the USSR Academy of Sciences
  • Members of the National Academy of Sciences of Ukraine
  • Modern synthesis (20th century)
  • Russian people of German descent
  • Scientists from Kyiv
  • Soviet zoologists
  • Taras Shevchenko National University of Kyiv alumni

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