| → various 1859 1860 1861 1866 |
| to the various 1869 1872 |
|
| → this has been the universal 1859 1860 1861 1866 |
| a single birthplace is the 1869 1872 |
|
| → on my theory have all 1859 1860 1861 1866 |
| must on the theory all be 1869 |
| must on our theory all be 1872 |
|
| → some part of 1859 1860 1861 1866 |
| OMIT 1869 1872 |
|
| → the area inhabited by their progenitor. 1859 1860 1861 1866 |
| some one area. 1869 1872 |
|
| → If it can be shown to be almost invariably the case, that a region, of which 1859 1860 1861 1866 |
| When 1869 |
| If, when 1872 |
|
|
have
rendered discontinuous the
continuous range of many species. So that we are reduced to consider whether the exceptions to continuity of range are so numerous and of so grave a nature, that we ought to give up the belief, rendered probable by general considerations, that each species has been produced within one area, and has migrated thence as far as it could. It would be hopelessly tedious to discuss all the exceptional cases of the same species, now living at distant and separated
nor do I for a moment pretend that any explanation could be offered of many
after some preliminary remarks, I will discuss a few of the most striking classes of facts; namely, the existence of the same species on the summits of distant mountain-ranges, and at distant points in the arctic and antarctic regions; and secondly (in the following chapter), the wide distribution of
productions; and thirdly, the occurrence of the same terrestrial species on islands and on the
though separated by hundreds of miles of open sea. If the existence of the same species at distant and isolated points of the
surface, can in many instances be explained on the view of each species having migrated from a single birthplace; then, considering our ignorance with respect to former climatal and geographical changes and
→various
occasional means of transport, the belief that
→this has been the universal
law, seems to me incomparably the safest. |
|
| In discussing this subject, we shall be enabled at the same time to consider a point equally important for us, namely, whether the several
species of a genus, which
→on my theory have all
descended from a common progenitor, can have
modification during
→some part of
their
from
→the area inhabited by their progenitor.
→If it can be shown to be almost invariably the case, that a region, of which
|
