Seeds of Hierarchy 225
But at that time [after the Malthusian insight of 1838 and his composition
of the sketches of 1842 and 1844] I overlooked one problem of great
importance; and it is astonishing to me, except on the principle of
Columbus and his egg, * how I could have overlooked it and its solution.
The problem is the tendency in organic beings descended from the same
stock to diverge in character as they become modified. That they have di-
verged greatly is obvious from the manner in which species of all kinds can
be classed under genera, genera under families, families under suborders,
and so forth (in F. Darwin, 1887, vol. 1, p. 84; the carriage statement
directly follows).Darwin (loc. cit.) then epitomizes the solution that he named "the principle of
divergence" and ranked with natural selection as a foundation of his theory: "The
solution, as I believe, is that the modified offspring of all dominant and increasing
forms tend to become adapted to many and highly diversified places in the
economy of nature."
Darwin's principle of divergence has puzzled many biologists: why did
Darwin rank the concept so highly, and as a principle separate from natural
selection? May we not view divergence as a logical consequence or simple spin-off
from natural selection itself? Yet when one considers the issue in Darwin's terms,
both his separation of divergence from natural selection, and his joy in resolution,
make excellent sense. Natural selection, as formulated under the Malthusian
insight of 1838, states a principle of anagenetic change within phyletic lines—an
argument about adaptation to local circumstances (biotic and abiotic). This
principle says nothing, by itself, about diversification, or splitting of one lineage
into two or several descendant
*The reference to Columbus and his egg puzzled me. The line is often quoted by
Darwin scholars, but never explained—so either everyone (but me) knows the old tale, or
else most people share my ignorance, and pass the issue by in embarrassed silence. Darwin
apparently cites the story as a standard motto, or a schoolboy tale taught to everyone. But
modern Americans (of my generation and younger) do not know the story—at least in my
informal, but reasonably obsessive, survey. I asked several older Europeans, and caught a ray
of light because some recalled such a tale from their distant educational pasts, but couldn't
dredge up the details. Finally, the letters column of the New York Times came through. The
old chestnut—this one I do know—about balancing an egg at the Spring equinox received an
ample airing in 1989, both in editorials and letters. A Mr. Louis Marck unwittingly submitted
this lovely resolution of Darwin's puzzling line in a letter of March 26 entitled "Columbus
also had a way with eggs":
In "It's Spring. Go Balance an Egg" (editorial March 19), you say that cheaters "crack the
shell to create a flat bottom." According to a tradition strangely unknown in this country,
one person who did that very thing, not as a cheater, but to prove a point, was Christopher
Columbus.
My German dictionary of quotations places the apocryphal incident in 1493, at a
banquet given in honor of Columbus by Cardinal Mendoza. When the difficulty of his
voyage of discovery was put into question, Columbus challenged his interlocutors to
balance an egg. When they failed, he did it by cracking the shell.
In German, as well as Spanish, "the egg of Columbus" has become proverbial for
solving a difficult problem by a surprisingly simple knack or expedient.