Species

186 Species

An example of this is the vestigial hind limbs in the Greenland whale.^119 So

Weismann was not exactly the panadaptationist he is sometimes made out to be,^120

and he also allowed for the existence of neutral characters. However, he rejected

outright the views of those who thought that isolation was a precondition to new spe-

cies and that the characters that formed them were in any way neutral. In discussing

variation, he notes that

... there are very variable species and very constant species, and it is obvious that

colonies which are founded by a very variable species can hardly ever remain exactly

identical with the ancestral species; and that several of them will turn out differently,

even granting that the conditions of life be exactly the same, for no colony will contain

all the variants of the species in the same proportion, but at most only a few of them,

and the result of mingling these must ultimately result in the development of a some-

what different form in each colonial area.^121

This is in some ways an early forerunner of the “founder effect” conception of
the origin of new species proposed by Mayr and developed further by Hampton
Carson.^122 What is most striking about this is that Weismann is effectively ascrib-
ing speciation in this case to stochastic sampling. This is something that, as the
strict selectionist Romanes held him to be, he should not have adopted. Weismann
opposed, though, an exclusivist position such as that of Wagner’s that all species had
to be formed in this way.

Bibliography

Amundson, Ron. 2005. The Changing Role of the Embryo in Evolutionary Biology: Structure
And Synthesis, Cambridge Studies in Philosophy and Biology. New York: Cambridge
University Press.
Barlow, Nora, ed. 1967. Darwin and Henslow: The Growth of an Idea; Letters, 1831–1860.
London: Murray for Bentham-Moxon Trust.
Beatty, John. 1985. Speaking of species: Darwin’s strategy. In The Darwinian Heritage,
edited by David Kohn. Princeton PA: Princeton, University Press.
Bernardi, G. et al. 2002. Species boundaries, populations and colour morphs in the coral reef
three-spot damselfish (Dascyllus trimaculatus) species complex. Proceedings of the
National Academy of Sciences of the United States of America 269 (1491):599–605.
Burkhardt, Frederick, ed. 1996. Charles Darwin’s Letters: A Selection, 1825–1859.
Cambridge/New York: University of Cambridge.
Burma, Benjamin H., and Ernst Mayr. 1949. The species concept: A discussion. Evolution 3
(4):369–373.
Campbell, George J. D., Duke of Argyll. 1884. The reign of law. 18th ed. London: Alexander
Strahan. Original edition, 1866.
Carlon, D. B., and A. F. Budd. 2002. Incipient speciation across a depth gradient in a sclerac-
tinian coral? Evolution; International Journal of Organic Evolution 56 (11):2227–2242.

(^119) Op. cit., vol. II, 313.
(^120) For example, by Gould 2002, 198ff.
(^121) Weismann 1904, 286.
(^122) Mayr 1954, Carson 1957, 1971, Coyne 1994.