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The Birth of the Genetic Theory of Evolution
in the Soviet Union in the 1920s
Theodosius Dobzhansky
When Darwin's On the Origin of Species was published in 1859, Russia
was entering a period of political reforms and a ground swell of radicalism
among its intelligentsia. The coincidence was fortuitous, but it left an
impress on the intellectual tradition. Evolution was accepted not only as
a scientific theory but also as a part of the liberal world view. Chernyshevsky
and Pisarev, standard bearers of the radical youth, proclaimed
that a valid personal philosophy must rest on a solid base of
natural science, and evolution was a pivotal part of that. Professor Kutorga
had lectured on Darwin's theory at Moscow University in 1860 and
published an account of it in 1861. A Russian translation of Darwin's
classic appeared in 1864. In 1865 Timiriazev, who was as effective an exponent
of Darwinism in Russia as Huxley in England or Haeckel in Germany,
published a collection of essays on evolution, which went through
seven editions by his death in 1920.
Politically conservative circles took a dim view of Darwin's work because
of its alleged political implications rather than evolution as a biological
theory. As Danilevsky, one of Darwin's critics, indicates, the
issue was taken extremely seriously: "It is clear how vitally important not
only for zoologists and botanists, but for any moderately intelligent person
is the issue whether Darwin is or is not right. It is so important that I
am firmly convinced that no equally important problem exists either in
any other field of knowledge or in any realm of practical life. Indeed, this
is the problem of 'to be or not to be' in the strictest and broadest sense."
The Orthodox church was never very active in its opposition to evolutionism,
and nothing like laws prohibiting the teaching of evolution or a
Tennessee "monkey trial" occurred in Russia. The polemics of the debate
were published neither in scientific nor in religious periodicals, but mostly
in general literary and sociopolitical journals intended for broad circles
of educated readers. This public did not usually have much understanding
of biology as a science, but its bearings on human problems were considered
important. When I was in my middle teens, a conservative lady
of our acquaintance asked me: "Do you really believe in this horrid
theory of Darwin?" I could have replied that those who do not credit this
horrid theory seem to me rather dull-witted.
Critics and Defenders of Darwinism
Among those who accepted evolution as a part of the new gospel, some
had reservations about certain parts of Darwin's theory. The struggle for
existence seemed to have particularly undesirable connotations; already
Chernyshevsky held the Lamarckian "transformism" superior to Darwin's
natural selection. Kropotkin's attempt to give primacy as an evolutionary
force to mutual aid, instead of competition and struggle, is
sufficiently well known, because his essays were published in an English
periodical (1902), while Kessler's "The Law of Mutual Aid" (1880), published
in Russian, was virtually ignored. The checkered career of neoLamarckism
in Russia has recently been well analyzed by Gaisinovich
(1968) and Bliakher (1971). The polemics about Lamarckism versus Darwinism
and genetics became a caricature of scientific discussion when the
problem was taken over by Marxist philosophers in the 1920s and early
1930s. The Timiriazev Institute was working on "the study and propaganda
of the scientific foundations of dialectical materialism." The Communist
Academy had a Section of Natural and Exact Sciences. The Faculty
of Medicine of Moscow University had a Society of Materialist
Physicians. The criterion of validity of theories of evolution was their
congruity with dialectical materialism as construed by different authorities.
I remember the frustration I felt discussing some problem of genetics
or evolution with Serebrovsky, an excellent geneticist and a convinced
Marxist, in 1926 or 1927. His clinching argument to me was, "Your reasoning
is undialectical." The debates among the high priests of dialectics
were often impassioned but inconclusive. Both Lamarckians and
Darwinians claimed to be faithful dialecticians. These polemics had however
a wholly unintended effect: they prepared the ground for Lysenko's
simplistic brand of dialectics, which for almost a generation swept away
much of biology in Russia.
Most evolutionists in Russia were, of course, busy doing biological research
rather than philosophizing. All approaches to evolutionary problems
explored in other countries had their proponents in Russia. One
tendency was particularly widespread and characteristic- a preoccupation
with the organic diversity and the congruity of organic structures
with the ways of living in different environments. Russia has a variety of
climates from arctic to subtropical, vast plains and high mountains, forests
and steppes, great rivers, lakes, and seas. Exclusively laboratory
workers who neither possess nor wish to have any knowledge of living
beings in nature were and still are a minority. Zoological and botanical
systematics, comparative anatomy, phylogenetic studies on fossil and
living forms, and later genetics were pursued in universities, as well as in
museums and laboratories under the aegis of the Academy of Sciences. It
was this tradition that yielded such evolutionists as Kovalevsky, Pavlov,
and Mechnikov in the 1800s and Berg, Chetverikov, Karpechenko, Levitsky,
Philipchenko, Schmalhausen, Severtzov, Vavilov, and many others
during the first third of the 1900s. Some of the numerous amateur naturalists
became very competent scientists. Genetics started tardily, but
developed with great elan once it did start. The first course of genetics
was given in the University of St. Petersburg by Philipchenko in 1913. I
never had a course of genetics at the University of Kiev, although my
teacher, Kushakevich, was an excellent cytologist and adherent of the
chromosome theory of heredity. At that time I was an entomologist specializing
in the taxonomy of Coccinellidae (lady beetles). Mendel's laws
were occasionally mentioned, though not in evolutionary context.
The theory of natural selection reached the nadir of its repute among
evolutionists in the early twentieth century. Russia was no exception, despite
the aging Timiriazev thundering against what he believed reactionary
forces bent on discrediting Darwinism. Perhaps the chief among the
panoply of arguments advanced against natural selection was the absence
of a clear correspondence between the organic diversity and the
diversity of the environments. In particular, the characteristics that distinguish
related species, and are utilized in taxonomic keys, appear to be
neither useful nor harmful to their possessors. In other words, those characteristics
are neutral traits, which natural selection can neither promote
nor eradicate. Identical arguments, now in vogue among the so-called
non-Darwinian evolutionists, who find no sense in the amino acid sequences
in the proteins of different forms of life, are to me distinctly deja
vu. The eminent systematist and zoogeographer Semenov-Tian-Shansky
compared nature to an artist who creates aesthetically appealing forms
for no reason other than their beauty. If a viable organism can be built
this way as well as that way, both kinds of organisms will exist. Natural
selection can only interdict what is inviable. The concept of mutation was
still rather unfamiliar to at least the older generation of biologists in the
1920s, even though the theories of de Vries and of his Russian anticipator
Korzhinsky were not unknown. However, in 1919 and 1922 Philipchenko
published in Priroda, a journal analogous to Science or to Nature,
excellent reviews of the works of the Morgan school on the genetics
of Drosophila. To me these reviews were a revelation. To most senior
biologists Drosophila mutants were a collection of monstrosities, of no
significance for evolution.
Neo-Lamarckism
To criticize the theory of natural selection was easy; to put something
better in its place very difficult. Some of the critics embraced neo-Lamarckism,
the inheritance of acquired traits. Smirnov, a brilliant young
zoologist at Moscow University, engineered in 1926 the invitation to
Kammerer to come to Russia to head a laboratory in which they would
have worked to establish the validity of Lamarckism, about which they
had not the slightest doubt to begin with. The plan came to naught owing
to Kammerer's suicide. The Lamarckists were a small minority among
biologists (though not, for a time, among philosophers and politicians).
(See Gaisinovich, 1968; Bliakher, 1971.)
The most widespread view was that evolutionary changes are induced
by the environments in which the organisms live. But the evolutionary
responses to the environment occur neither via natural selection nor via
the inheritance of acquired traits. It is rather by means of direct influences
of the "geographical landscape" on the germ plasm of the inhabitants
of a given territory. Berg gave a most articulate exposition of this
view, which he accepted as a subsidiary to his nomogenesis theory. The
geographical landscape subsumes "the external environment in the widest
sense, physical as well as biotic factors united in one harmonious
whole." The geographical landscape "affects organisms in an imperative
manner, compelling all the individuals, so far as the organization of the
species permits, to vary in a determined manner. There is no place here
for chance: consequences follow with the same fatal constancy as chemical
reactions or physical phenomena." Just how the "harmonious whole"
changes the genotype was left quite vague. Those who attempted to explicate
this puzzle (Berg was not one of them) postulated direct alteration
of the genetic materials by environmental factors, rather than somatic or
parallel inductions favored by the Lamarckians. Evidence that could be
quoted in support was scanty in the extreme: the now discredited experiments
of Tower on the beetle Leptinotarsa, and the also discredited induction
of inheritable eye defects by antibodies in rabbits, alleged by
Guyer and Smith. Muller's discovery of gene and chromosomal mutations
in Drosophila induced by ionizing radiations was, of course, a
firmly established demonstration of genetic changes by an environmental
agency, but hardly relevant to the geographical landscape theory.
Nomogenesis
More interesting was Berg's theory of nomogenesis (1922). A man of
splendid intellect and great personal charm. Berg developed his views in
a book marshaling an abundance of evidence comparable to Darwin's
On the Origin of Species. For a year or two after reading Berg's work I
was close to becoming a partisan of nomogenesis. To Berg the phylogeny
is basically similar to the ontogeny - the development follows paths predetermined
by causes internal to the organism. The environment and
natural selection permit or prohibit the survival of a new form but are
not competent to bring it into existence. Evolutionary changes are subject
to laws analogous to, and perhaps consubstantial with, those of embryonic
development. With impeccable honesty. Berg admits that his putative
"laws" leave unexplained the adaptedness of organisms to their environments.
He postulates that adaptedness is an immanent property of
living matter. Nomogenesis was attacked from all sides. Dialectical
Marxists rightly saw that nomogenesis borders on vitalism. Lamarckians
were displeased that Berg not so much denied as ignored acquired traits
and somatic induction. His book has no reference to Kammerer's works
being hotly debated at that time. Genetics also receives inadequate attention,
which is hardly surprising because Berg wrote his book mostly
before biological literature published abroad since 1914 had reached the
blockaded Russia.
The Rise of Genetics
Scientists in Russia had an extraordinary experience of being almost
wholly isolated from world science for about seven years, and then obtaining
access at once to what was accomplished during this period by
their colleagues abroad. To those interested in genetics and evolution this
amounted to a sudden revelation. The review of the work of the Morgan
school on Drosophila published by Philipchenko in 1922 was an eyeopener
to many. Muller visited Russia in 1922 and left a fair number of
cultures of Drosophila mutants at Koltsov's Institute of Experimental
Biology in Moscow the seed from which grew the Russian school of
Drosophila genetics. Moscow geneticists were generous with the gift; I
was enabled to start working with Drosophila mutants in Kiev early in
1923, as were other converts to Drosophila studies elsewhere. I myself
left Russia on the morning of December 4, 1927, having received a postgraduate
fellowship to work one or two years in Morgan's laboratory. I
did not suspect at all, when I left, that I might stay on after the expiration
of the fellowship.
There were three nuclei of genetics research in the 1920s. By far the
largest were the Institute of Applied Botany headed by Vavilov, with
headquarters in Petrograd (later Leningrad), Koltsov's Institute of Experimental
Biology in Moscow, and Philipchenko's department of genetics
at the University of Leningrad. Vavilov, soon joined by Karpechenko,
Levitsky, and numerous other botanical and agricultural geneticists,
maintained his familiarity with current ideas and research in genetics and
evolution, despite what to almost anybody else would have been a crushing
load of administrative responsibilities. Koltsov's personal interests
were in cell biology, in what later became molecular genetics, and finally
in eugenics. Two of the several sections in his Institute of Experimental
Biology were headed by Chetverikov and Serebrovsky. They attracted a
number of talented young researchers, some of whom became eventually
leading figures in evolutionary biology in Russia and abroad. Among
them were Timofeeff-Ressovsky, Astaurov, Romashov, and Dubinin.
Sergei Chetverikov
Chetverikov's classic paper (1926) showed that evolution is brought
about by natural selection acting on a store of genetic variability generated
by mutation. Between 1930 and 1932, the same theory was expounded
with greater mathematical refinements by Fisher, Wright, and
Haldane. The four "founding fathers" thus provided the cornerstone of
what later became the biological, or synthetic, theory of evolution. Chetverikov's
work would have received much greater renown had it not
been published in Russian in a journal with limited distribution abroad.
As it was. Fisher, Wright, and Haldane were simply unaware of Chetverikov's
contribution. It did, however, stimulate a great deal of research
activity in Russia and eventually abroad. As a background against which
to see the crosscurrents in evolutionary biology in Russia in the 1920s
and 1930s, brief sketches of some of the personalities involved in the apparently
sudden blossoming of evolutionary studies may be useful.
Chetverikov started as a naturalist working on systematics and ecology
of Lepidoptera. He had a contemplative turn of mind and, although
he was a steady worker, he published little. His interest in the expansions
and contractions of the populations of various species in time led to the
publication in 1905 of "Waves of Life," a rather short but allusive article.
His great 1926 essay is only 52 pages long, although it contains enough
material to make an at least medium-sized book. Chetverikov was at his
best in face-to-face discussions with colleagues and students. His sharp
and rigorous analysis of evolutionary problems was accompanied by
constructive ideas and suggestions for research. He shared his ideas with
his interlocutors with complete selflessness. Trying to establish his priority
seemed to him unworthy of a scientist.
I had the privilege of several visits with him in his laboratory in Moscow.
Though at that time I was only a bit more than half as old as he
was, Chetverikov was unstinting with his time and inspiring with his advice.
He disliked writing letters, however, which proved to be a blessing
in disguise for me. Otherwise I might have shared the fate of Timofeeff-Ressovsky
in Germany, instead of coming to work with Morgan in the
United States. Chetverikov was an experimentalist as well as a theoretician.
Even before the publication of his 1926 theoretical paper, he initiated
a study of what later became known as genetic loads, in natural
populations of Drosophila tnelanogaster. The results were reported
briefly in a paper read in 1927 at the International Genetics Congress in
Berlin, and in a very short paper published in Russian in 1928. In 1929
Chetverikov was exiled, because, it was rumored, he was denounced to
the political police by one of his students. This incident occurred before
Stalin's terror reached its peaks of brutality. Although Chetverikov was
never able to develop the work begun so auspiciously with his many students
in Moscow, he remained alive until 1959. Recognition, in the form
of the Darwin medal award by the German Academy Leopoldina,
reached him shortly before he died at the age of seventy-nine.
Alexander Serebrovsky
Serebrovsky accepted Chetverikov's theory of evolution. His own work
developed quite independently and in somewhat different directions,
however. He was an adherent of the now almost forgotten presenceabsence
theory, originated chiefly by Bateson in England, which for reasons
beyond my comprehension seemed to Serebrovsky particularly
congenial with Marxist dialectics. This theory postulated that most mutations
are minute deficiencies, little holes in the chromosomes. Serebrovsky
attempted to measure the size of the assumed "hole," by estimation
of the map distance in centimorgans between two marker genes on both
sides of a mutant in Drosophila melanogaster. Together with his student
Dubinin, he interpreted the so-called step allelism at the gene locus of
scute in Drosophila in terms of overlapping deficiencies in a series of
linearly arranged subgenes.
Of more lasting interest and significance are Serebrovsky's studies on
gene geography, first published in Russian in 1927. Chicken populations
in the Caucasus (Dagestan) are highly polymorphic, and the gene frequencies
differ considerably in nearby mountain valleys, as well as elsewhere
in the Soviet Union. This led Serebrovsky to formulate the concept
of the gene pool, which he called the gene fund ("genofond"). His
interest in the human gene pool landed him in trouble. Independently
from Muller, Serebrovsky advanced a plan of improvement of human
populations by means of artificial insemination of women with the semen
of eugenically desirable donors. This plan was too much for the then poet
laureate Demian Bedny (eventually himself destroyed in Stalin's terror).
Serebrovsky was blasted and ridiculed in Pravda and elsewhere by totally
ignorant hacks. When Lysenko became the ruler of biology, Serebrovsky
turned to applied genetics and put forward the idea of pest control by
means of release of masses of individuals that would produce sterility or
lethality in the recipient populations. This idea was surely ahead of his
time, but he had no opportunity to make even small-scale tests of its applicability.
When genetics, particularly Drosophila genetics, was
banned, Serebrovsky, the ardent believer in communism and dialectical
materialism, died a forlorn and embittered man, just when Lysenko
reached the peak of his glory.
Juri Philipchenko
Philipchenko built a school perhaps smaller than those of Chetverikov
and Serebrovsky, but his impact on the evolutionary and genetical
thought in Russia was, if anything, greater. He wrote six textbooks and
numerous review articles on various aspects of genetics and evolution
that were used in institutions of higher learning until Lysenko's pogrom.
The first course of genetics in Russia was given by Philipchenko from
1913 until he was forced to resign his professorship at the University of
Leningrad a year before his death in 1930. His books and lectures were
didactically flawless: the depth and breadth of his scholarship were as
admired by his students and colleagues as they were feared by his opponents.
And yet this man of superb intellect fell short of fulfillment of his
capabilities, in part because of his untimely death, and in part because of
the skeptical and overcritical turn of his mind. He was always able to see
a host of alternative explanations for any phenomenon and to poke holes
in any theory. Yet while a deficiency of critical ability is fatal to a scientist,
its excess may be frustrating; life is too short to test every alternative,
and one has to accept the most probable one, subject, of course, to
possible falsification.
Philipchenko welcomed Chetverikov's mutation-natural selection
theory, but stressed that it might be only a part, and a rather minor part
of the story. The genes and the Mendelian inheritance may be pertinent
only to superficial traits, distinguishing individuals within a species or
species within a genus; fundamental features, those of orders, classes,
and phyla, may be inherited and changed by quite different and as yet
unknown mechanisms. This view was a minority position but scientifically
quite respectable in the 1920s. Similar opinions were held, for example,
by the Danish geneticist Johannsen. Though a zoologist by training,
in the last decade of his life Philipchenko worked on the genetics and
ontogeny of certain characteristics in species of wheat and other grasses.
The results were neither in accord with his expectations nor flatly contradictory.
Had he lived longer he might well have changed his evolutionary
credo. As it was, he still played a most useful role not only as a teacher
but also as a stimulant of critical thought and research in evolutionary
biology.
Between 1924 and 1927 I was the counterpart of an assistant professor
in Philipchenko's department in Leningrad. Moscow is just a night railway
journey away, so I visited there rather frequently. At that time at
least, the second-class tickets were reasonably cheap. I did not, however,
participate in the actual work done at the Koltsov Institute. When I
visited there, I looked at what they were doing but I cannot claim the
honor of having been one of Chetverikov's students. The subject of my
own research in Philipchenko's laboratory in the years 1924-1927 was the
effect of pleiotropic genes in Drosophila. However, I never lost my interest
in Coccinellidae.
As an entomologist I had read On the Origin of Species, I believe in
1915, when I was all of fifteen years old. I also read German entomological
literature because my main foreign language then was German. One
of my beloved books was that of Standfuss, describing experiments on
butterflies and moths. The transition from that to Drosophila was very
easy. Berg's nomogenesis was a temporary infatuation: it sounded very
remarkable and it took me some time to recover my independent judgment.
Berg was a very impressive and certainly brilliant man.
The Great Institutes
Vavilov headed the Institute of Applied Botany (later the Institute of
Plant Industry, still later the Lenin Academy of Agricultural Sciences).
Koltsov was the director of the Institute of Experimental Biology. In its
heyday Vavilov's institute had local sections and experiment stations in
all parts of the Soviet Union and included among its research workers, if
only on a part-time basis, nearly every geneticist and cytologist working
with plants as materials. Koltsov's institute was not quite so large, but it
had a powerful group of both young and old research workers. Research
and thinking of the then avant-garde evolutionary biology were active in
both institutions.
Vavilov and Koltsov were eminent scientists in their own right. As administrators,
they necessarily sacrificed much of their personal research
potentials for the sake of furthering the work of others. In a sense, their
greatest discoveries were the outstanding creative scientists whom they
chose as their colleagues and leaders of various research projects. In 1922
Vavilov established the law of homologous series in genetic variabilities.
Notably in related species of cultivated plants, but also in wild species,
the mutation process generates alleles of homologous genes that produce
phenotypically similar variants. Artificial and natural selections then
choose from this assortment the genotypes suitable for survival and exploitation.
Some overenthusiastic reporters went so far as to compare
this law with the periodic system of chemical elements. Vavilov's other
major contribution, based on his extensive familiarity with cultivated
plants of the world, was locating the geographic "centers of origin" of the
domesticated forms. He was inclined to equate these centers with regions
of maximum genetic variability in the respective species. For a few years
preceding his arrest and death in prison, Vavilov was stripped of administrative
work and devoted his time to studies of the evolution of cultivated
plants; his publications of that period seem to lack much of his
former ardor.
Levitsky and Karpechenko were two outstanding evolutionary cytogeneticists
among Vavilov's cohorts. Levitsky, originally professor of
botany at the Faculty of Agriculture in Kiev, published The Material
Basis of Heredity (1924) and Cytological Basis of Evolution (1939). Karpechenko
obtained fertile allopolyploid hybrids of radish and cabbage, a
classic example of emergence of a full-fledged new species, by doubling
the chromosomal complements in otherwise sterile interspecific hybrids.
Both Levitsky and Karpechenko were articulate speakers and writers and
stimulated a great deal of genetic and evolutionary research among botanists,
not only in Leningrad but elsewhere in the far-flung system of Vavilov's
experiment stations. Inevitably they ran afoul of Lysenkoism,
were arrested in 1941, and died in prisons or concentration camps.
Koltsov was a man of multifarious interests and knowledge, of imposing
presence, and with the eloquence of a spellbinding orator. His public
lectures were events memorable to his peers and to beginners alike. His
main field of research was cell biology; some Russian writers claimed
that Koltsov discovered the main features of the genetic code
[see Ref.1], although
he believed (as did biologists in general in his time) that the genetic information
is stored in proteins rather than in the nucleic acids. He realized
clearly the basic importance of Mendelian genetics for the elucidation of
evolutionary processes and gave full support to Chetverikov, Serebrovsky,
and other geneticists working in his institute and elsewhere. One of
the Koltsovians, Timofeeff-Ressovsky, had a remarkable life; for about
two decades after leaving Koltsov's institute he worked with great success
in Germany, then spent some years in Soviet prisons, and finally
emerged the most eminent evolutionary geneticist in the Soviet Union.
Eugenics seemed to be an important application of genetics to Koltsov.
He was the organizer and the moving spirit of the Russian Eugenics Society
and of its periodical, a perilous undertaking in the Soviet Union,
especially when eugenics was among the slogans of the waxing Nazism in
Germany. No matter how much effort Koltsov and Philipchenko made
to separate their eugenics from the racist teachings of the Nazis, they
were easy marks for the accusations of the Lysenkoists that all eugenics,
and in fact all genetics, are pernicious inventions of the capitalists. The
last years of Koltsov's life, though he avoided arrest and imprisonment,
were poisoned by unceasing harassments. He was lucky to die of a sudden
heart attack; his wife committed suicide within a few hours after his
death.
The Flourishing State of Russian Genetics
One of the most impressive aspects of Russian genetics in the 1920s was
the size of the genetics establishment. In England, few were interested in
evolutionary genetics besides Bateson, Fisher, Haldane, Huxley, and
Ford. In Germany, there was some interest in physiological genetics, but
aside from Baur there was no population geneticist until Timofeeff-Ressovsky
arrived from Russia.
In contrast, three schools flourished in Russia, each with numerous
investigators. Numerically the largest school, of course, was that of Vavilov,
although much of its research was applied. Chetverikov's group
consisted in 1927 of twelve people doing Drosophila research, as well as
five visitors to the group (Zhivago, a cytologist, Frolova, Serebrovsky,
Sacharov, and Koltsov). Serebrovsky had his own group that included
Dubinin among others. Frolova has the distinction of having discovered
the difference between European Drosophila obscura and U.S. "obscura."
When she was unable to cross the two stocks, she examined the
chromosomes and found them to be quite different. She and Astaurov
described the American sibling species as D. pseudoobscur a.
It is sometimes remarked that Russian geneticists seemed to be much
more of the naturalist type than pure experimentalists, perhaps because
of the great size and environmental diversity of the country. New and
unusual animals and plants were steadily collected and brought for study
in university laboratories, zoological and botanical museums, and marine
institutes. Most biologists had experience working in the field and
observing living beings in their habitats. Most young biologists traditionally
spent a year or more abroad in "postdoctoral" work (although there
were no doctorates in our sense), usually including visits to Naples' marine
zoological station or similar institutions. It was taken for granted
that a biologist must know animals or plants, or both.
Severtsev and Schmalhausen
Severtsev and Schmalhausen were evolutionary morphologists, working
on comparative anatomy and embryology of vertebrates. Severtsev's interests
centered on the relationships between phylogeny and ontogeny,
and led him to conclusions in many ways resembling those of Rensch and
Simpson published two decades later. Severtsev viewed the mechanisms
that bring about evolution in the light of classical Darwinism; he regarded
natural selection the leading agent and considered the inheritance
of acquired traits neither proved nor completely ruled out. He was certainly
not opposed to the genetical theories of evolution being developed
by Chetverikov and others, but rather felt that geneticists should do their
business while he and his collaborators were doing theirs. To enthusiastic
young geneticists in the mid-1920s this attitude seemed narrow-minded if
not outright retrograde. Philipchenko was among those who pointed out
that the narrow-mindedness was more likely the foible of the young enthusiasts
because evolutionary biology is multidimensional, not only a
specialized branch of genetics.
Schmalhausen was one of Severtsev's pupils, but by the late twenties
while a professor of zoology in Kiev, he became interested in the genetic
factors bringing about evolutionary changes. As Severtsev's successor as
director of the Institute of Evolutionary Morphology in Moscow, Schmalhausen
published a series of books on evolution that belong to the period
of the emergence of the synthetic theory rather than to its incipience.
Schmalhausen's analysis of the varieties of natural selection is fully modern
and has in no way lost its significance today. As could have been expected,
Schmalhausen was attacked by Lysenkoists and expelled from
the directorship of his institute, but fortunately avoided the arrest and
imprisonment that then commonly befell biologists who refused to compromise
their scientific and personal integrity. In his last years Schmalhausen
became interested in cybernetics and its applications to evolutionary
biology.
The Emergence of a Paradigm
In his essay on the Russian school of evolutionary genetics, Adams
(1968) remarks: "The Russian school is important both because of what it
ended and what it began. Many authors have alluded to the estrangement
between two traditions in biology which characterized its history in
the early decades of this century: the experimentalist' and the naturalist'
traditions. It is significant, then, that the Russian school is one of the earliest
to draw from both traditions in order to clarify the evolutionary
process." Russian biologists habitually viewed the evolutionism in two
contexts: that of its philosophical implications, and in the light of life as it
exists in pristine nature. To be acceptable, a paradigm had to pass scrutiny
from these points of view, in addition to being valid on purely factual
grounds.
Why had such a paradigm emerged when it did and not earlier or later?
Interest in evolutionary problems was traditional among Russian biologists
since the nineteenth century. Except for the years during World War
One and the subsequent revolutionary upheaval, Russia was not a scientific
backwater. Current scientific literature in major European languages
was not only available but it was read rather more systematically than is
the foreign-language literature now in the United States. Acquaintance
with the experimental work of the Morgan school, and with the findings
of other geneticists in Europe and in the United States, became possible
only in about 1921. However, this exposure would have been insufficient
without Chetverikov's insight and without the experiments on the genetics
of natural populations that he promptly undertook to test the validity
of his theoretical construct.
It now seems almost unbelievable that quite authoritative biologists in
the 1920s and 1930s in Russia as well as in Europe and the United States
contended that the phenomenon of mutation has no bearing whatever
on evolution. Drosophila mutants described by the Morgan school were
monstrosities, and they were all found in laboratory bottles, not in natural
populations, products of some kind of disruption of hereditary
materials in highly artificial environments. The claim of de Vries and his
followers that new species arise by single mutational leaps seemed incompatible
with everything that systematists and paleontologists had learned
about species in living and fossil forms. It was therefore quite logical and
necessary that the experimental work of Chetverikov and his collaborators
and students was directed toward testing for the presence of mutants
in natural populations of Drosophila. They explicitly considered
their work to be the decisive test of the validity of the theory, and the
results of the test turned out to be positive. After Chetverikov ran afoul
of the political police and was banished from Moscow, the work went
ahead under the direction of Timofeeff-Ressovsky in Germany, and by
Dubinin, Romashov, and others in the Soviet Union.
It is tempting to represent a scientific discovery of a given person or of
a group of persons at a given time too neatly as an automatic consequence
of a certain scientific tradition. After all, the basic features of the
mutation-natural selection theory of evolution were discovered almost
simultaneously and certainly quite independently from Chetverikov by
Fisher, Wright, and Haldane. The personal backgrounds and the scientific
traditions of this Anglo-American trinity were quite different from
Chetverikov's, as well as from each other. It is well known that Mendelism
and genetics in general were, by a singular miscomprehension, regarded
as contradictory to Darwin's theory of natural selection in the
early decades of the twentieth century. The short but important theoretical
paper by Hardy in 1908 should have dispelled this miscomprehension,
and in fact it served as a point of departure for Chetverikov as well
as for the other founding fathers (the parallel work of Weinberg was not
then considered). By the 1920s the mutation-natural selection theory was
definitely in the air, and four persons independently seized it. Analogously,
in the thirties and forties, what we now call the synthetic theory
was in the air, a logical complement to the Chetverikov-Fisher-Wright and Haldane
theoretical base, and at least eight biologists of different backgrounds
and traditions have brought it down to earth. Some of them,
fortunately, are still alive in the 1970s and can tell their stories.
References
Because of Dobzhansky's death before his selection had been fully prepared for
publication, there is no list of references such as appears after the other selections.
Many of the books and articles cited by Dobzhansky appear, however, in
other chapters of this book [Ernst Mayr etc. The Evolutionary Synthesis
Perspectives on the Unification of Biology, 1980; The second edition 1998], and complete information is given there. Eds.
References
Ref1. (Yury Neretin) ... some Russian writers claimed
that Koltsov discovered the main features of the genetic code.
Simon Shnoll claims that the idea that genetics is based on duplication of long moleculas was firstly
formulated by Koltsov . Later it became well-known in Europe due to Timofeeff-Resovsky.
A quotation
Этот парадокс — малое число молекул и множество
признаков — впечатался а сознание Кольцова. Он думал о нем
многие годы, пытаясь разрешить разными способами. Он
опубликовал свое решение в 1927 году в докладе на 3-м
Всесоюзном съезде зоологов, анатомов и гистологов, т.е. через
34 года. Ответ этот звучит торжественно. Сущность его такова:
признаки, передаваемые по наследству, определяются линейным
расположением мономеров в полимерных молекулах. (Кольцов
думал, что это последовательность аминокислот в
полипептидах.) Эти гигантские полимерные молекулы (их в самом деле
мало в клетке) размножаются по принципу матриц:
свободные мономеры из раствора сначала выстраиваются вдоль
«родительской» молекулы — матрицы, выстраиваются в
соответствии с последовательностью мономеров в этой матрице. А
затем образуются химические связи, сшивающие прилипшие
к матрице мономеры с образованием точной «дочерней»
копии. Эти полимерные молекулы размножаются как кристаллы.
Читателю ясно, что это — формулировка самой главной
идеи биологии XX века.
Идея матричного синтеза была забыта не понявшими ее
современниками. Забыта не всеми. В 1925 году учеников
Н.К.Кольцова и С.С.Четверикова — супругов Тимофеевых-Ресовских по рекомендации Н.К.Кольцова и Н.А.Семашко
советское правительство командировало для работы в
Германию, в институт профессора Фогта. Громогласный,
энциклопедически образованный Н.В.Тимофеев-Ресовский
рассказывал об этой идее на своих ставших знаменитыми
семинарах в Берлин-Бухе, в своих многочисленных докладах
на конференциях, семинарах, съездах в разных странах, в
том числе на семинарах Нильса Бора в Копенгагене.
Идея матричного синтеза особенно легко усваивалась
физиками. Это можно понять. «Нет пророка в своем
(биологическом) отечестве». Пророк — биолог в отечестве
физиков — тут ему внимают с почтением и доверием. Да и по
существу — главные доводы в пользу матричной концепции
из области физики. Совершенно невероятно выстраивание в
правильной последовательности мономеров в полимерной
цепи в обычных химических реакциях...
Когда великий физик Эрвин Шредингер читал свои
лекции (по теоретической биологии!) в университете, его
предметом и был взгляд на биологию с точки зрения
физика. Он основывал свои взгляды на представлениях об
одномерном кристалле, на термодинамике и матричной
концепции, полагая, что она, эта концепция, общепринята
у биологов. Когда его лекции были опубликованы в виде
знаменитой книги «What is Life? The Physical Aspect of the
Living Cell», Дж.Б. Холден откликнулся на нее статьей в
«Nature»: концепция не общепринята в биологии, а
принадлежит великому российскому биологу Кольцову!