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J. Maruani
‘elements’ (states of matter we would say): earth, water, air, and fire, under the action
of two opposed ‘trends’: love and strife (attraction and repulsion we would say). At
the beginning, elements were merged under the sole action of love. Then strife arose
and initiated heterogeneous structures, both inorganic and organic. Afterwards there
came sexes and species. The different parts of the bodies were first built separately
and then gathered at random: only survived those beings that were best fit to their
environment.
A century later Aristotle, to whom Darwin gives credit in his Origin of species,
stated that ‘Nature evolves in a continuous manner from inanimate to animal forms’,
that ‘in plants one finds a progressive ascension to animal life’, and that ‘animal
life involves a gradual differentiation in vitality and motricity’. The same beliefs led
Aristotle to teach that insects can arise from mud or manure, and later Pline claimed
that they can also arise from snow or fire. The belief in ‘spontaneous generation’
went through the Middle Ages with no visible conflict with biblical creationnism. It
was five years after Darwin’s Origin of species that Pasteur magistrally refuted this
millenary belief.
A more relevant precursor of scientific transformism is Erasmus Darwin, the very
grandfather of Charles Darwin, who foresaw Lamarck’s theory and evoked sexual
selection in his Zoonomia. But it was Jean-Baptiste Monet de Lamarck who proposed
the first consistent system of explanation of biological evolution by means of transmissible adaptative variations leading to increased complexity [2]. But Lamarck also
believed in permanent, spontaneous generation and orthogenetic progression on the
scale of life. Although Lamarck greatly contributed to spread transformism, his theory is now viewed as obsolete for being too closely linked to the transmission of
acquired characters. However, it should be noted that Darwin himself, while putting
the stress on natural (and sexual) selection of individual variations [3], attributed
their genesis to the environment and also believed in the transmission of acquired
characters. It was in the light of later discoveries [6–13] that the major importance
of his specific contributions appeared, and it was neodarwinists as Jacques Monod
[17] who expurged the theory of biological evolution of every trace of Lamarckism.
While Lamarck had focused his interest on the evolution through successive eras
(vertical evolution), Darwin first tried to understand how different species emerge in
different areas (horizontal evolution). The divergence between him and Lamarck was
most clearly expressed by Wallace, the codiscoverer of natural selection. In his book
Darwinism (1889), he presented a theory free of the vitalist elements that Darwin had
maintained. But Wallace differed from Darwin—and from Haeckel, a codiscoverer of
sexual selection and a supporter of Lamarck’s theory—on a major point: he refused
to admit that Man is a simple product of natural and sexual selection; the brain and
hand of Man, he wrote, ‘were in advance on the needs of their possessor’.
Other findings improved our knowledge of the living world. (1) Permanence of
hereditary characters and statistical laws of their hybridation by Austrian monk Gregor Mendel (experiments on peas) in 1865. (2) Distinction of soma and germen ‘plasmas’ by German biologist August Weismann in 1892. (3) Spontaneity and heredity
of mutations by Dutch botanist Hugo de Vries in 1903. (4) Chromosome theory of
heredity by American zoologist T. H. Morgan (experiments on drosophiles) in 1910.
J. Maruani
‘elements’ (states of matter we would say): earth, water, air, and fire, under the action
of two opposed ‘trends’: love and strife (attraction and repulsion we would say). At
the beginning, elements were merged under the sole action of love. Then strife arose
and initiated heterogeneous structures, both inorganic and organic. Afterwards there
came sexes and species. The different parts of the bodies were first built separately
and then gathered at random: only survived those beings that were best fit to their
environment.
A century later Aristotle, to whom Darwin gives credit in his Origin of species,
stated that ‘Nature evolves in a continuous manner from inanimate to animal forms’,
that ‘in plants one finds a progressive ascension to animal life’, and that ‘animal
life involves a gradual differentiation in vitality and motricity’. The same beliefs led
Aristotle to teach that insects can arise from mud or manure, and later Pline claimed
that they can also arise from snow or fire. The belief in ‘spontaneous generation’
went through the Middle Ages with no visible conflict with biblical creationnism. It
was five years after Darwin’s Origin of species that Pasteur magistrally refuted this
millenary belief.
A more relevant precursor of scientific transformism is Erasmus Darwin, the very
grandfather of Charles Darwin, who foresaw Lamarck’s theory and evoked sexual
selection in his Zoonomia. But it was Jean-Baptiste Monet de Lamarck who proposed
the first consistent system of explanation of biological evolution by means of transmissible adaptative variations leading to increased complexity [2]. But Lamarck also
believed in permanent, spontaneous generation and orthogenetic progression on the
scale of life. Although Lamarck greatly contributed to spread transformism, his theory is now viewed as obsolete for being too closely linked to the transmission of
acquired characters. However, it should be noted that Darwin himself, while putting
the stress on natural (and sexual) selection of individual variations [3], attributed
their genesis to the environment and also believed in the transmission of acquired
characters. It was in the light of later discoveries [6–13] that the major importance
of his specific contributions appeared, and it was neodarwinists as Jacques Monod
[17] who expurged the theory of biological evolution of every trace of Lamarckism.
While Lamarck had focused his interest on the evolution through successive eras
(vertical evolution), Darwin first tried to understand how different species emerge in
different areas (horizontal evolution). The divergence between him and Lamarck was
most clearly expressed by Wallace, the codiscoverer of natural selection. In his book
Darwinism (1889), he presented a theory free of the vitalist elements that Darwin had
maintained. But Wallace differed from Darwin—and from Haeckel, a codiscoverer of
sexual selection and a supporter of Lamarck’s theory—on a major point: he refused
to admit that Man is a simple product of natural and sexual selection; the brain and
hand of Man, he wrote, ‘were in advance on the needs of their possessor’.
Other findings improved our knowledge of the living world. (1) Permanence of
hereditary characters and statistical laws of their hybridation by Austrian monk Gregor Mendel (experiments on peas) in 1865. (2) Distinction of soma and germen ‘plasmas’ by German biologist August Weismann in 1892. (3) Spontaneity and heredity
of mutations by Dutch botanist Hugo de Vries in 1903. (4) Chromosome theory of
heredity by American zoologist T. H. Morgan (experiments on drosophiles) in 1910.