charles_darwin

The Reception of Darwin’s Theories, 1859–1920
explanation of the cause of mutation became Neo-Lamarckian
because he could not explain some of the gaps in his theory. For
example, if there were numerous transitional forms between a species
and a variety about to become a new species, why was there no
evidence of these transitional forms in the geological record? In
Chapter IX of the first edition of The Origin of Species, Darwin
argued that the geological record itself was ‘‘extremely imperfect.’’
Even if it was possible to know what the transitional forms between
a parent species and a new one looked like—and Darwin did not
think it was—such a large amount of time had elapsed since some of
the transmutations occurred that the geological evidence had been
destroyed. 8 This answer did not satisfy some naturalists, hence Darwin’s
use of Lamarck’s idea.
Even if the imperfection of the geological record explained the
missing transitional links, there were other, equally difficult, problems
with a theory that relied on numerous small mutations. How
could these mutations produce ‘‘large’’ abilities, such as the instinct
in birds to lay their eggs in the nests of other birds? Or, if a plant
that mutated could become a hybrid, how could small mutations
overcome the sterility of plant hybrids? Using the examples of slavemaking
ants and the comb-building of bees, Darwin showed that
apparently innate instincts were not, in fact, natural. By comparing
the work of Karl G€artner and Joseph K€olreuter (1733–1806) with his
own experiments, Darwin demonstrated that sterility in plants was
caused mainly by interbreeding not by hybridity. 9
Darwin did provide answers to some of the criticisms he anticipated
but, as his theory was so universal, so all-encompassing, his
answers did not and could not satisfy every naturalist. His chapters
on the geographical distribution of species suggested that the orthodox
view of the fixity of species was untenable, but that did not
mean naturalists were bound to accept Darwin’s theory of descent by
modification. Just because oceanic islands have many distinct or
unique species did not mean naturalists had to accept that evolution
had occurred. 10
Seen in this context, the debates about The Origin of Species,
Darwin’s ideas, and Darwinism make sense. With regard to The
Origin of Species, naturalists discussed whether the book was well
argued. When discussing Darwin’s ideas about transmutation and
speciation, naturalists discussed whether descent by modification
was a viable scientific theory. As for the theory of evolution, naturalists
debated whether they should accept Darwin’s theory of
evolution—which Thomas Huxley called Darwinism—or some other
theory. And mixed in with the scientific debates were the questions
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