continually being made to explain the origin of all organic forms by
some system of development or evolution. Buffon had dwelt on the
modifications directly induced by the environment. Lamarck had made much
use of this idea, claiming that such modifications were transmitted to
posterity, and claiming the same for the structural changes produced by
use and disuse. Lamarck's work did not become at all popular while he
lived, chiefly through the overpowering influence of Baron Cuvier, who
had an equally fantastic scheme of his own, which may well be termed a
burlesque on Creation and in which an extreme fixity of "species" was a
cardinal doctrine. Erasmus Darwin and Robert Chambers in England also
tried to make a theory of evolution believable; though their efforts
were but little more successful in gaining the ear of the world.

But to all that had gone before Charles Darwin and A.R. Wallace (1858)
added the idea of "natural selection," or "the struggle for existence,"
to use the respective terms coined by each of these authors, as the
chief means by which the effects of variation are accumulated and
perpetuated so as to build up the modern complexities of the plant and
animal kingdoms. Partly because it was a psychological moment, from the
fact that the uniformitarian geology of Lyell with its graded advance of
existences from age to age seemed absolutely to demand some evolutionary
explanation; partly because artificial selection was a familiar idea of
proved value in selective breeding, and "natural selection" seemed an
exact parallel carried on by nature in the direction of continual
improvement; but perhaps more largely because the abstract idea of
"natural selection" involved so many intricate separate concepts that
for nearly a generation scarcely two naturalists in the world could
state the whole problem of the theory exactly alike;--on all these
accounts the theory of natural selection, or of the "survival of the
fittest," to use the phrase of Herbert Spencer, became in the latter