| → within each class thus 1861 1866 1869 1872 |
| thus 1859 1860 |
|
| → they are spread 1869 1872 |
| spread they are 1859 1860 1861 1866 |
|
| → As some few of the 1872 |
| A few 1859 1860 1861 1866 |
| Some few 1869 |
|
| → old 1859 1860 1861 1866 1872 |
| of these old 1869 |
|
| → forms have 1872 |
| parent-forms having occasionally 1859 1860 1861 1866 |
| forms having 1869 |
|
| → these constitute 1872 |
| will give to us 1859 1860 1861 1866 |
| constitute 1869 |
|
| → OMIT 1869 1872 |
| on my theory 1859 1860 1861 1866 |
|
| → as at present by 1872 |
| by 1859 1860 1861 1866 1869 |
|
| → or by two or three. 1872 |
| but such richness in species, as I find after some investigation, does not commonly fall to the lot of aberrant genera. 1859 1860 1861 1866 |
| or by one or two. 1869 |
|
| → forms which have been 1869 1872 |
| failing groups 1859 1860 1861 1866 |
|
| → still preserved under unusually favourable conditions. 1869 1872 |
| preserved by some unusual coincidence of favourable circumstances. 1859 1860 1861 1866 |
|
|
that of the other members of the family to which it belonged. There is, however, some difficulty on this head, for it is necessary to suppose in some cases that ancient members belonging to several distinct groups, before they had diverged to their present extent, accidentally resembled a member of another and protected group in a sufficient degree to afford some slight protection, this having given the basis for the subsequent acquisition of the most perfect resemblance. |
|
On
the
Nature
of
the
Affinities
connecting
Organic
Beings
.—
|
| As the modified descendants of dominant
belonging to the larger genera, tend to inherit the
which made the groups to which they belong large and their parents dominant, they are almost sure to spread widely, and to seize on more and more places in the economy of nature. The larger and more dominant groups
→within each class thus
tend to go on increasing in size; and they consequently supplant many smaller and feebler groups. Thus we can account for the fact that all organisms, recent and extinct, are included under a few great orders,
still fewer
As showing how few the higher groups are in number, and how widely
→they are spread
throughout the world, the fact is
that the discovery of Australia has not added
insect belonging to a new
and that in the vegetable kingdom, as I learn from Dr. Hooker, it has added only two or three
of small size. |
|
| In the chapter on
I attempted to show, on the principle of each group having generally diverged much in character during the long-continued process of modification, how it is that the more ancient forms of life often present characters in some
degree intermediate between existing groups.
→As some few of the
→old
and intermediate
→forms have
transmitted to the present day descendants but little modified,
→these constitute
our so-called osculant or aberrant
The more aberrant any form is, the greater must be the number of connecting forms which
→OMIT
have been exterminated and utterly lost. And we have some evidence of aberrant
having suffered severely from extinction, for they are
represented by extremely few species; and such species as do occur are generally very distinct from each other, which again implies extinction. The genera Ornithorhynchus and Lepidosiren, for example, would not have been less aberrant had each been represented by a dozen
instead of
→as at present by
a single
→or by two or three. We can, I think, account for this fact only by looking at aberrant
as
→forms which have been
conquered by more successful competitors, with a few members
→still preserved under unusually favourable conditions.
|
