Mr. Belloc says he has not (“Argument from Evidence”). He says it
very emphatically (“Crushing Argument from Evidence”--to adopt the
phraseology of his cross-heads). Let me refer him to a recent lecture
by Sir Arthur Keith (Royal Society of Medicine, Nov. 16, 1925) for a
first gleam of enlightenment. He will realise a certain rashness in his
statement. I will not fill these pages with an attempt to cover all
the changes in the average man that have gone on in the last two or
three thousand years. For example, in the face and skull, types with
an edge-to-edge bite of the teeth are giving place to those with an
overlapping bite; the palate is undergoing contraction, the physiognomy
changes. And so on throughout all man’s structure. No doubt one can
find plentiful instances to-day of people almost exactly like the
people of five thousand years ago in their general physique. But that
is not the point. The proportions and so forth that were exceptional
then are becoming prevalent now; the proportions that were prevalent
then, now become rare. The average type is changing. Considering that
man only gets through about four generations in a century, it is a
very impressive endorsement of the theory of Natural Selection that he
has undergone these palpable modifications in the course of a brief
score of centuries. Mr. Belloc’s delusion that no such modification has
occurred may be due to his presumption that any modification would have
to show equally in each and every individual. I think it is. He seems
quite capable of presuming that.