| → look at the 1861 1866 |
| take, as the standard of high organisation, the amount of 1869 |
| take as the standard of high organisation, the amount of 1872 |
|
| → as the best standard of highness of organisation, 1861 1866 |
| OMIT 1869 1872 |
|
| → they perform in this state 1861 1866 1869 |
| in this state they perform 1872 |
|
| → ill-occupied 1861 1866 1869 |
| unoccupied or less well occupied 1872 |
|
|
stamens, and pistils, fully developed in each flower; whereas other botanists, probably with more truth, look at the plants which have their several organs much modified and
reduced in number as
the
|
|
| If we
→look at the
differentiation and specialisation of the several organs
each being when adult (and this will include the advancement of the brain for intellectual
→as the best standard of highness of organisation,
natural selection clearly leads towards
for all physiologists admit that the specialisation of organs, inasmuch as
→they perform in this state
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
→ill-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
|
