1 The Birth of Science - MSRI

5.6 Botany and Zoology 139
in fossils that can be documented today on the part of Theophrastus and
Eratosthenes was presumably shared by other authors.
We have seen, then, that the bases of modern evolutionism, namely the page 181
notions of mutation and natural selection, were both present in Hellenistic
thought. 62 Did these notions lead to full-fledged evolutionary theories?
The almost complete loss of zoological and botanical works precludes a
definite answer, but it should be noted that general ideas about evolution
in nature predate ideas about natural selection and mutations; they are
repeatedly brought up (and criticized) by Aristotle, who attributes them
once to Speusippus and to “some Pythagoreans” and again, more vaguely,
to his own contemporaries. 63 Moreover, a rationalist explanation for animal
evolution seems to be present already in Anaxagoras, who remarked
that man owes his intelligence to his hands. 64 Prescientific versions of biological
evolution were expounded by various pre-Socratic thinkers, from
Anaximander 65 to Empedocles; the latter imagined, for example, that once
there had lived on earth monstrous beings formed by the random combination
of disjoint animal limbs. 66 Lucretius seems to be referring scientific
objections to Empedocles’ idea when he writes:
That there were many seeds of things on the ground
at the time when the earth first produced animals
does not at all mean that beasts could have arisen
mixed among themselves, nor combined animal limbs,
because the species that even now populate the land
— of herbs, of fruit, of luxuriant plants —
cannot be created in confusion with each other,
“petrified Indian cane” ( ; De lapidibus, 38), as well as by references
to petrification made by Pliny and others.
62 Regarding selection mechanisms, we see already in Plutarch the important observation that in
the struggle for survival a species is placed in opposition not to its predators but to its competitors,
those that would eat the same food. Plutarch also makes an interesting analogy with economic
competition (De fraterno amore, 486B).
63 Aristotle, Metaphysica, XII, 1072b, 30 – 1073a, 3; XIV, 1091a, 31–36; 1092a, 11–17. See also [Pop-
per: OSE], note 11 to chapter 11.
64 This important observation of Anaxagoras is reported by Aristotle (De partibus animalium, IV,
687a, 8–10), Plutarch (De fraterno amore, 478D–E) and Galen (De usu partium, iii, 5). Aristotle, who
just before this passage had noted the relationship between the use of hands and an erect posture,
rejects Anaxagoras’ thesis and states that, contrariwise, nature gave hands to humans because,
being intelligent, they would be able to use them. Both Plutarch and Galen crib Aristotle’s opinion.
65 We know through Aetius that Anaximander maintained, in particular, that life started in the
water ([DG], 430).
66 Fragments 6–7 in [Empedocles/Gallavotti] = frs. 35, 57–61 in [Diels: FV], vol. I, pp. 326–328,
333–334. (Gallavotti’s edition contains a conjectural partial reconstruction of Empedocles’ Physical
poem assembled from fragments that were transmitted in isolation.) The concept of chance, in particular,
seems clearly expressed in the verse ¥ (fr. 59
in Diels).
Revision: 1.9 Date: 2002/09/14 19:12:01