Objections to Origin which Owen and Wilberforce could have used. Why have incipient mammalian forms not arisen from lower vertebrates on islands separated since Miocene period? Knows CD would not derive Eocene Mammalia from higher reptiles, but would bats not be modified into other mammalian forms on an ancient island? This is not the case in New Zealand. Why have island seals not become terrestrial? Assumes rate of change is greatest in mammals. Difficulties are small compared with ability to explain absence of Mammalia in pre-Pliocene islands. Asks about descent of Amblyrhynchus. Believes objections apply equally well to independent creation of animal types, but not if the First Cause is allowed completely free agency.
The grand argument from absence of mammalia & batrachians in Oceanic islands is probably felt to be strong by Owen as he has not ventured to impugn it and therefore declined to bring it into notice.
It is a very telling argument & I think just & true, tho` if I had been
helping Owen & the Bishop I fancy I could have suggested objections but I have
not thought them out yet, & have not therefore troubled you with them, thinking
I remember however it struck me that the putting it even as possible that the Galapagos or Cape de Verds could have been joined to the nearest Continent was dangerous, as in the case (p. 390) they must have retained some of the smaller mammalia. Also if atolls be remnants of sunk continents would not some of the old continental land quadrupeds have survived or have been slowly modified into amphibious & volant species.
Also, if as I believe the Canaries & Madeiras have been islands ever since the Miocene period (& the Azores), would not the theory of Nat. Selection have time to modify any vertebrate animal into the lowest of the Lyencephala in such a lapse of ages. Or if not, does it not give us a sort of scale for the vast geological time required for such a transmutation. No Galapagos saurian, having risen to a mammal. Perhaps you will say that this would be a greater puzzle to the out-&-out progressionists who may be converted by you to transmutation. Bronn, e.g., for you do not believe in that constant advance, as an ever working tendency, & allow for stationary & retrograde movements.
You would prefer I conceive to derive Eocene mammalia from the Microlestes of the Trias
rather from any reptilian of however high a grade e.g. a deinosaurian. You
But if an island be very ancient the bats would be modified into mammalia of other genera & orders long before any bird could be turned into a mammal. Here comes the question, how old is the oldest isolated Oceanic island? The miocene littoral shells of Grand Canary & of Porto Santo give a miocene date to those lands, already in all probability separated from the Continent as now. But there are no bats there.
New Zealand is so large it probably existed from Eocene times as land?? Why did not
bats getting there diverge into a dominant mammalian volant fauna & some lose
their wings & become non-volant mammalia? Or why did not seals & marine
mammalia turn terrestrial in their habits if they had such a geological period as the
post-miocene for nat
If there was time in Galapagos to convert a marine Amblyrhincus into a land species or vice versa. why not a phoca into a land species or other cetaceae into terrestrial. Did the land Amblyrhincus come first into being & of what S. American Saurian was he or his aquatic congener a modification? If all these questions apply equally against independent acts of Creation they will not be very damaging. But when the free agency of the First Cause is allowed to come into play, it may be said that no mammalia were wanted because it was foreseen that Man would come with his attendant train of useful mammals, taking even the camel with success into the Canaries.
- f1 2900a.f1The text of the letter has been taken from a draft, in Mary Elizabeth Lyell's hand, in Lyell's scientific journal. It is also printed in Wilson ed. 1970, pp. 467--9. The copy is headed: `Letter to Darwin from Rudolstadt'. Lyell was travelling on the Continent: from 2 to 8 August 1860 he was in Rudolstadt, Germany (ibid., p. 490 n. 88).
- f2 2900a.f2CD discussed the geographical distribution of Mammalia and batrachians in Origin, pp. 393--5. Lyell refers to Richard Owen's assistance in the writing of Samuel Wilberforce's review of Origin ([Wilberforce] 1860).
- f3 2900a.f3Lyell refers to CD's theory of the origin of coral reefs, according to which coral atolls had been formed as the seabed subsided (see Coral reefs). Apparently Lyell had forgotten that CD no longer believed that groups of atolls indicated the location of a former landmass (see Correspondence vol. 6, letter from Charles Lyell, 17 June 1856, and letter to Charles Lyell, 25 June ).
- f4 2900a.f4According to Richard Owen, Lyencephala, including the monotremes and marsupials, were the most primitive mammals (R. Owen 1859a).
- f5 2900a.f5Heinrich Georg Bronn, who prepared the German translation of Origin, gave his reasons for believing in the progressive introduction of species in Bronn 1858b. See also Junker 1991.
- f6 2900a.f6The bear--whale story in the first edition of Origin, p. 184, was derived from a remark in a book by Samuel Hearne (Hearne 1795).