...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.
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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,
..
speculation on the subject is
almost useless. almost useless. 1872 | useless. 1866 1869 |
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 |
towards the close of the Introduction,
...OMIT 1866 1869 1872 |
where I say that 1861 |
no one ought to feel surprise at much remaining as yet unexplained on the origin of species, if
we make due allowance we make due allowance 1869 1872 |
due allowance be made 1861 1866 |
for our profound ignorance on the mutual relations of the inhabitants of the world
at at 1872 | during 1861 1866 1869 |
the
present time, and still more so during past ages. present time, and still more so during past ages. 1872 |
many past epochs in its history. 1861 1866 |
past epochs in its history. 1869 |
↑Subtitle not present 1859 1860 1861 1872 |
Various
Objections
considered.
1866 1869 |
|
...OMIT 1872 |
I need allude only to two other objections: a distinguished botanist, 1869 |
Mr. H. C.
Watson
thinks
that I have overrated the importance of divergence of character (in which, however, he apparently believes), and that
convergence, convergence, 1872 | convergence 1869 |
....... 1872 | of character, 1869 |
as it may be called, has likewise played a part. If If 1872 |
I will only remark that if 1869 |
two
species, species, 1872 | species 1869 |
belonging to two distinct though belonging to two distinct though 1872 |
of two 1869 |
allied genera,
had both
produced a
large number large number 1872 | number 1869 |
of new and divergent
forms, it is conceivable that these might forms, it is conceivable that these might 1872 |
species, I can believe that they might sometimes 1869 |
approach each other so closely that they would
have all to have all to 1872 |
for convenience sake 1869 |
be classed
under
the same
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genus;
and thus
the descendants of two distinct the descendants of two distinct 1872 |
two 1869 |
genera would converge into
one.
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.. But it would in most cases be extremely rash to attribute to convergence a close and general similarity of structure in the modified descendants of widely distinct forms. The shape of a crystal is determined solely by the molecular forces, and it is not surprising that dissimilar substances should sometimes assume the same form; but with organic beings we should bear in mind that the form of
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