| → take as the standard of high organisation, the amount of 1872 |
| look at the 1861 1866 |
| take, as the standard of high organisation, the amount of 1869 |
|
| → OMIT 1869 1872 |
| as the best standard of highness of organisation, 1861 1866 |
|
| → in this state they perform 1872 |
| they perform in this state 1861 1866 1869 |
|
| → unoccupied or less well occupied 1872 |
| ill-occupied 1861 1866 1869 |
|
| ↑ 1 blocks not present in 1859 1860 1869 1872; present in 1861 1866 |
| I need hardly say that Science in her present state does not countenance the belief that living creatures are now ever produced from inorganic matter.
|
|
| → has not as yet proved the truth of this 1872 |
| however, under her present aspect does not countenance the 1869 |
|
| → reveal. 1872 |
| reveal, that living creatures are now being generated. 1869 |
|
| → or the survival of the fittest, does not necessarily include progressive 1869 1872 |
| includes no necessary and universal law of advancement or 1861 1866 |
|
|
probably with more truth, look at the plants which have their several organs much modified and
reduced in number as
the
|
|
| If we
→take as the standard of high organisation, the amount of
differentiation and specialisation of the several organs
each being when adult (and this will include the advancement of the brain for intellectual
→OMIT
natural selection clearly leads towards
for all physiologists admit that the specialisation of organs, inasmuch as
→in this state they perform
their functions better, is an advantage to each being; and hence the accumulation of variations tending towards specialisation is within the scope of natural selection. On the other hand, we can see, bearing in mind that all organic beings are striving to increase at a high ratio and to seize on every
→unoccupied or less well occupied
place in the economy of nature, that it is quite possible for natural selection gradually to fit
being to a situation in which several organs would be superfluous
useless: in such cases there
be retrogression in the scale of organisation. Whether organisation on the whole has actually advanced from the remotest geological periods to the present day will be more conveniently discussed in our chapter on Geological Succession. |
|
| But it may be objected that if all organic beings thus tend to rise in the scale, how is it that throughout the world a multitude of the lowest forms still exist; and how is it that in each great class some forms are far more highly developed than others? Why have not the more highly developed forms everywhere supplanted and exterminated the lower? Lamarck, who believed in an innate and inevitable tendency towards perfection in all organic beings, seems to have felt this difficulty so strongly, that he was led to suppose that new and simple forms
continually being produced by spontaneous generation. ↑
→has not as yet proved the truth of this
belief, whatever the future may
→reveal. On
theory the
existence of lowly
offers no difficulty; for natural
→or the survival of the fittest, does not necessarily include progressive
development— it only takes advantage of such variations as arise and are beneficial to each creature under its complex relations of life. And it may be asked what advantage, as far as we can see, would it be to an infusorian animalcule— to an intestinal worm— or even to an earth-worm, to be highly
If it were no advantage, these forms would be
by natural
unimproved or but little
and might remain for indefinite ages in their present
condition. And geology tells us that some of the lowest forms, as the infusoria and rhizopods,
|
