| → common 1859 1860 1861 1866 |
| are still common 1869 1872 |
|
| → nearly 1859 1860 1861 1866 |
| the striking relation of nearly 1869 1872 |
|
| → being related in the most striking manner 1859 1860 1861 1866 |
| OMIT 1869 1872 |
|
| → those of 1859 1860 1861 1866 |
| of those of 1869 1872 |
|
| → other 1859 1860 1861 1866 |
| of the other 1869 1872 |
|
| → constitute one grand natural system, with 1859 1860 1861 1866 |
| can be arranged within a few great classes, in 1869 1872 |
|
| → species and genera 1859 1860 1861 1866 |
| forms 1869 1872 |
|
|
The existence of closely allied or representative species in any two areas, implies, on the theory of descent with modification, that the same
formerly inhabited both
and we almost invariably find that wherever many closely allied species inhabit two areas, some identical species
→common
to
Wherever many closely allied yet distinct species occur,
doubtful forms and varieties
the same
occur. It is a rule of high generality that the inhabitants of each area are related to the inhabitants of the nearest source whence immigrants might have been derived. We see this in
→nearly
all the plants and animals of the Galapagos archipelago, of Juan Fernandez, and of the other American
→being related in the most striking manner
to the plants and animals of the neighbouring American mainland; and
→those of
the Cape de Verde
and
→other
African islands to the African mainland. It must be admitted that these facts receive no explanation on the theory of creation. |
|
| The fact, as we have seen, that all past and present organic beings
→constitute one grand natural system, with
subordinate to
and with
groups often falling in between
groups, is intelligible on the theory of natural selection with its contingencies of extinction and divergence of character. On these same principles we see how it is, that the mutual affinities of the
→species and genera
within each class are so complex and circuitous. We see why certain characters are far more serviceable than others for classification;— why adaptive characters, though of paramount importance to the
are of hardly any importance in classification; why characters derived from rudimentary parts, though of no service to the
are often of high classificatory value; and why
|
