It was Georges Cuvier, Professor of Zoology at the Muse´um d’Histoire Naturelle in Paris, who began to establish some fundamental principles for the study of fossils see Famous Geologist
Trang 1Palaeontology and Comparative
Anatomy
Organic fossils had been known for centuries and by
the eighteenth century few doubted that they were
former living organisms Fossil collecting became a
popular, and even lucrative, pastime, especially when
large specimens of ammonites, ichthyosaurs, ancient
fishes, mammoths, etc., were discovered Many
collec-tions, in private or public hands, were initiated It was
Georges Cuvier, Professor of Zoology at the Muse´um
d’Histoire Naturelle in Paris, who began to establish
some fundamental principles for the study of fossils (see
Famous Geologists: Cuvier) He started by trying to
reassemble collections of mastodon bones from
Amer-ica They were manifestly creatures rather similar to
modern elephants, so he used the known arrangement
of elephant bones for purposes of comparison, in order
to reconstruct the mastodon skeleton In this work, he
recognized that the total structure must be one in which
all the parts fit together to form a ‘working whole’; and
the structures must be such as to enable the creatures to
live successfully in their ‘conditions of existence’ This
‘goodness of fit’ necessarily applied to the lost soft parts
as well as those that had become fossilised So Cuvier
enunciated his principle of ‘co-ordination of parts’
However, most fossils were shells, etc., and it was
Cuvier’s colleague Jean-Baptiste Lamarck who was
re-sponsible for collecting and studying these He was the
first to make a formal distinction between vertebrates
and invertebrates and state the major divisions of the
latter Only then could invertebrate palaeontology
make a proper start It was less easy to make
com-parative anatomical studies for fossil invertebrates
than for vertebrates, though Charles Darwin (see
Famous Geologists: Darwin) later famously did so
with barnacles
In examining the fossil record, Cuvier found that
there were substantial and apparently sudden changes
in the fossil record as one ascended the stratigraphic
column This finding largely holds to this day for
macrofossils, though smooth trends are known for
for-aminifera The biostratigraphic ‘breaks’ were, in fact,
convenient for stratigraphic investigations and
map-work such as that conducted by William Smith, but
their theoretical explanation was difficult, using
modern analogies as Cuvier had done for his mastodon
work Cuvier’s explanation was couched in terms of
sudden and catastrophic events (which we might call
mega-tsunamis), of unknown cause, perhaps of global
extent (Cuvier was inconsistent in his statements as to
the universality or otherwise of his catastrophes)
Fam-ously, he wrote that in these supposed events ‘‘the
thread of operations is here broken; the march of
Nature is changed’’ His doctrine was later dubbed
‘catastrophism’ by William Whewell, and there was the suggestion that the very laws of nature were broken
or suspended during such catastrophes; or past events were quite unlike anything occurring today
Seventeenth- and eighteenth-century writers such
as Steno (see Famous Geologists: Steno) had some-times propounded ‘catastrophist’ theories of the Earth because they had a greatly compressed time-scale for Earth history, supposedly in line with the
‘Biblical’ age of the Earth, of some 6000 years This was not Cuvier’s view He wrote: ‘‘Genius and science have burst the limits of space; Would it not also be glorious for man to burst the limits of time, and, by means of observations, to ascertain the history of this world, and the succession of events which preceded the birth of the human race?’’ This was the voice of modern geology His theory envisaged geological dir-ection and progress, taking place over unspecifiably great periods of time However, he was unable to account for the origin of new living forms (unlike Lamarck, he was no evolutionist) He thought there was a catastrophe some 5000–6000 years ago
Geology and Religion/Theology
It is easy to overplay the connections between geo-logy and religion in the early years of the nineteenth century But they certainly existed and were interest-ing and important One line of approach, taken by the Swiss naturalist Jean-Andre´ de Luc, who was greatly concerned to ‘harmonise’ geology and Biblical his-tory, was to suppose that there had been a great catastrophe, perhaps 5000 years ago, which separated history into antediluvian and postdiluvian eras, the division being associated with the Noachian Flood The period since the Flood could be estimated by the rate of lake infilling, or thickness of peat accumula-tions Such evidences almost allowed the date of the Flood to be quantified empirically Antediluvian time could be regarded as virtually limitless, the ‘days’ of Creation being of unspecified duration De Luc’s em-pirical work was, in fact, leading him towards a date corresponding with what we regard as the end of the last ice age Nature was playing him a cruel trick!
At Oxford, there had been lectures in geology for many years The field fell into desuetude in the late eighteenth century but the Reverend William Buck-land gave popular lectures there from 1814 to 1849, and particularly in his early years he endeavoured to show linkages between Cuvierian geology and Bib-lical history, identifying Cuvier’s last catastrophe with the Noachian Flood Buckland specially interested himself in cave deposits, supposing that the animal bones found therein might be the remains of animals that had sheltered in the caves or had been washed
176 HISTORY OF GEOLOGY FROM 1780 TO 1835