CHAPTER X. ON THE IMPERFECTION OF THE GEOLOGICAL RECORD.
4. ON THE ABSENCE OF NUMEROUS INTERMEDIATE VARIETIES IN ANY SINGLE FORMATION. (continued)
It has been asserted over and over again, by writers who believe in the
immutability of species, that geology yields no linking forms. This
assertion, as we shall see in the next chapter, is certainly erroneous. As
Sir J. Lubbock has remarked, "Every species is a link between other allied
forms." If we take a genus having a score of species, recent and extinct,
and destroy four-fifths of them, no one doubts that the remainder will
stand much more distinct from each other. If the extreme forms in the
genus happen to have been thus destroyed, the genus itself will stand more
distinct from other allied genera. What geological research has not
revealed, is the former existence of infinitely numerous gradations, as
fine as existing varieties, connecting together nearly all existing and
extinct species. But this ought not to be expected; yet this has been
repeatedly advanced as a most serious objection against my views.
It may be worth while to sum up the foregoing remarks on the causes of the
imperfection of the geological record under an imaginary illustration. The
Malay Archipelago is about the size of Europe from the North Cape to the
Mediterranean, and from Britain to Russia; and therefore equals all the
geological formations which have been examined with any accuracy, excepting
those of the United States of America. I fully agree with Mr. Godwin-
Austen, that the present condition of the Malay Archipelago, with its
numerous large islands separated by wide and shallow seas, probably
represents the former state of Europe, while most of our formations were
accumulating. The Malay Archipelago is one of the richest regions in
organic beings; yet if all the species were to be collected which have ever
lived there, how imperfectly would they represent the natural history of
the world!
But we have every reason to believe that the terrestrial productions of the
archipelago would be preserved in an extremely imperfect manner in the
formations which we suppose to be there accumulating. Not many of the
strictly littoral animals, or of those which lived on naked submarine
rocks, would be embedded; and those embedded in gravel or sand would not
endure to a distant epoch. Wherever sediment did not accumulate on the bed
of the sea, or where it did not accumulate at a sufficient rate to protect
organic bodies from decay, no remains could be preserved.
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