In mid-nineteenth century Britain the possibility of
evolution and particularly the evolution of man from apes
was vigorously contested. Among the leading anti-evolutionists
was the celebrated anatomist and paleontologist, Sir Richard
Owen and among the leading defenders of evolution was
T. H. Huxley.
In his argument against the evolution of humans from
apes and, more generally, against the possibility of organic
evolution, Owen claimed that the human brain was fundamentally
different from that of the ape brain and therefore the
transmutation of one species into the other was impossible.
The uniqueness of the human brain, he claimed, was that
only it had a "hippocampus minor". This structure, today
termed the "calcar avis" is in fact, a rather small indentation
in the wall of the lateral ventricle of the brain.
Huxley set out on a systematic campaign to disprove Owen's
claim of the uniqueness of the human brain. His purpose
was not merely to correct Owen's supposed anatomical error,
but to portray him as dishonest and incompetent and therefore
to eliminate him as a credible critic of Darwin's theory
of evolution. Huxley and his allies proceded to demonstrate
(and exaggerate) the existence of a hippocampus minor
in a great variety of primate species. In the course of
his anatomical studies Huxley discovered and named the
calcarine sulcus. The controversy over the hippocamus
minor evoked widespread interest in the lay media. Huxley
used it to help transfer power from the dominent Oxbridge
clergyman-naturalists to the new professional scientists,
at the center of which were Huxley and his allies.
At this time little was known about the functions of
the brain structure. Owen's stress on the importance of
ventricular anatomy derived from the central position
of the brain ventricles in Galen's system of physiology
which had dominated physiology and medicine from the second
century into the nineteenth.
This tale illustrates both the extraordinary persistence
of ideas in biology and the role of the political and
social matrix of science. It also exemplifies the continuing
attempt of humans to differentiate themselves from the
rest of the animal kingdom.
