Biology Reference
In-Depth Information
“In this chapter I have attempted to show that the subordination of
group to group in all organisms throughout all time, that the nature
of the relationship, by which all living and extinct beings are united
by complex, radiating, and circuitous lines of affinities into one
grand system ... all naturally follow on the view of the common
parentage of those forms which are considered by naturalists as
allied, together with their modification through natural selection,
with its contingencies of extinction and divergence of character. In
considering this view of classification, it should be borne in mind
that the element of descent has been universally used in ranking
together the sexes, ages, and acknowledged varieties of the same
species, however different they may be in structure. If we extend
the use of this element of descent — the only certainly known cause
of similarity in organic beings —
we shall understand what is
meant by the natural system: it is genealogical in its
attempted arrangement, with the grades of acquired dif-
ference marked by the terms varieties, species, genera,
families, orders, and classes
”
48
(OS pp. 432-433).
As we can see, Darwin's thinking is very far from Aristotle's. On
the other hand, before analysing genetics, we must emphasise the
extent to which his ideas approach those of Bernard. These two
authors lived at the same time and they both left decisive marks on
their discipline, thrusting it into modernity. It is not usual to con-
sider them together because they concerned themselves with very dif-
ferent subjects, yet they have in common a totally anti-essentialist
vision. We have just discussed Darwin's position in regard to the
species and we have seen that, for his part, Bernard questioned the
objective reality of functions (chapter 6, §6.1.3). His anti-essentialism
led him to formulate a more radical position, since he put the very
notion of the individual organism into perspective in order to
enhance the idea of a biological continuum very close to the notion
of the genealogical line in his analysis of morphogenesis:
48
Original text not in bold.
