Finally, I believe that
many lowly | many lowly 1869 1872 | | lowly 1861 1866 |
organised forms now exist
..| ..... 1869 1872 | | in numbers 1861 1866 |
throughout the world,
...| OMIT 1869 1872 |
| and in nearly every class, 1861 1866 |
from various causes. In some cases
variations or individual differences of a favourable nature | variations or individual differences of a favourable nature 1869 |
| favourable variations 1861 1866 |
| variations or individual differences of a favorable nature 1872 |
may never have arisen for natural
selection | selection 1861 1869 1872 | | selec- tion 1866 |
to act on and accumulate. In no case, probably, has time sufficed for the utmost possible amount of development. In some few cases there
has | has 1869 1872 | | may have 1861 1866 |
been what we must call retrogression of organisation. But the main cause lies in the
fact | fact 1869 1872 | | circumstance 1861 1866 |
that under very simple conditions of life a high organisation would be of no service,— possibly would be of actual disservice, as being of a more delicate nature, and more liable to be put out of order and
..| ..... 1869 1872 | | thus 1861 1866 |
injured. |
...| OMIT 1869 1872 |
| A difficulty, diametrically opposite to this which we have just been considering, has been advanced, namely, 1861 1866 |
Looking | Looking 1869 1872 | | looking 1861 | | that, looking 1866 |
to the
first dawn | first dawn 1869 1872 | | dawn 1861 1866 |
of life, when all organic beings, as we may
believe, | believe, 1869 1872 | | imagine, 1861 1866 |
presented the simplest structure,
how, | how, 1869 1872 | | how 1861 1866 |
it has been asked, could | it has been asked, could 1869 1872 |
| could 1861 1866 |
the first steps in
the advancement or differentiation | the advancement or differentiation 1869 1872 |
| advancement or in the differentiation and specialisation 1861 1866 |
of parts have arisen? ↑| 1 blocks not present in 1859 1860 1866 1869 1872; present in 1861 | | I can make no sufficient answer; and can only say that as we have no facts to guide us, all speculation on the subject would be baseless and useless.
|
Mr. Herbert Spencer would probably answer
that
as soon as
..| ..... 1869 1872 | | the most 1866 |
simple unicellular organism came by growth or division to be compounded of several cells, or became attached to any supporting surface, his law
...| OMIT 1869 1872 |
| would come into action, namely, 1866 |
"that homologous units of any order become differentiated in proportion as their relations to incident forces become
different" would come into action. | different" would come into action. 1869 1872 |
| different." 1866 |
But as we have no facts to guide us,
all
speculation on the subject is
useless. | useless. 1866 1869 | | almost useless. 1872 |
It is, however, an error to suppose that there would be no struggle for existence, and, consequently, no natural selection, until many forms had been produced: variations in a single species inhabiting an isolated station might be beneficial,
and | and 1861 1869 1872 | | and, 1866 |
thus | thus 1869 1872 |
| through their preservation either 1861 |
| through their preservation, either 1866 |
the whole mass of individuals might
be | be 1869 1872 | | become 1861 1866 |
modified, or two distinct forms might arise.
But, | But, 1866 1869 1872 | | But 1861 |
as I remarked | as I remarked 1866 1869 1872 |
| I must recur to what was stated 1861 |
|