The geological evidence of evolution / by Angelo Heilprin.

  • Heilprin, Angelo, 1853-1907.
Date:
1888
Catalogue details

Licence: Public Domain Mark

Credit: The geological evidence of evolution / by Angelo Heilprin. Source: Wellcome Collection.

    21/130 (page 5)
    o what is the nature of the proof that would be required of the geologist to establish its validity ? He would be required to show, in the first place, that there has been a steady advance in the type of structural organization from first to last—not a necessary elimination of forms of low degree, but an overbalancing of these by forms of a more complicated or higher grade of structure. Evo- lution does not hold, as some opponents of the theory would lead us to suppose, that the progres- sive modification of individual organic forms need be, or indeed has been, one of continuous advance; it recognizes merely a general advance for the entire organic frame, while it admits of indi- vidual retardation or degeneration. Its progress or procession is the equivalent of the progress seen in the development of civilization ; the united world advances, whereas individual tribes or nations remain at a standstill, or even degenerate and decay. Such is precisely the history of the organic devel- opment of our planet; new and more complicated organic types are being continually evolved, but