Origin of Species Variorum

→ sea or of the land; and, consequently, the competition between fresh-water productions will have been less severe than elsewhere; new forms will have been more slowly formed, and old forms more slowly exterminated. 1859 1861 1866 1869

most anomalous forms now known in the world, as the Ornithorhynchus and Lepidosiren, which, like fossils, connect to a certain extent orders now widely separated in the natural scale. 1860

sea or of the land. Consequently, the competition between fresh-water productions will have been less severe than elsewhere; new forms will have been then more slowly produced, and old forms more slowly exterminated. 1872

→ And it is in fresh water that we find seven genera of Ganoid fishes, remnants of a once preponderant order: and in fresh water we find some of the most 1859 1861 1866 1869

These 1860

And it is in fresh-water basins that we find seven genera of Ganoid fishes, remnants of a once preponderant order: and in fresh water we find some of the most 1872

→ now known in the world, as the Ornithorhynchus and Lepidosiren, which, like fossils, connect to a certain extent orders now widely separated in the natural scale. 1859 1861 1866

may almost be called living fossils; they have endured to the present day, from having inhabited a confined area, and from having thus been exposed to less severe competition. 1860

now known in the world, as the Ornithorhynchus and Lepidosiren, which, like fossils, connect to a certain extent orders at present widely separated in the natural scale. 1869

now known in the world, as the Ornithorhynchus and Lepidosiren, which, like fossils, connect to a certain extent orders at present widely sundered in the natural scale. 1872

→ severe 1859 1861 1866

varied and therefore less severe 1869

varied, and therefore less severe, 1872

→ up the circumstances favourable and unfavourable to natural selection, 1859 1860 1861 1866

up the circumstances favourable and unfavourable for the production of new species through natural selection, 1869

up, 1872

→ permits. 1859 1860 1861 1866 1869

permits, the circumstances favourable and unfavourable for the production of new species through natural selection. 1872

→ OMIT 1861 1866 1869 1872

looking to the future, 1859 1860

→ and which consequently has existed for long periods in a broken condition, has been 1861 1866

and which consequently will exist for long periods in a broken condition, will be 1859

and which consequently will exist for long periods in a broken condition, is 1860

will have been 1869 1872

→ long 1859 1860 1861 1866

for a long time 1869 1872

→ first 1860 1861 1866

will first have 1859

OMIT 1869 1872

→ at this period 1859 1860 1861 1866

will have been 1869 1872

→ species will thus have been 1861 1866

species will thus be 1859 1860

new species will have been 1869 1872

→ have been 1861 1866 1869

be 1859 1860

have been very 1872

→ Its action depends on there being 1859 1860 1861 1866

The result depends on there being 1869

It can act only when there are 1872

→ polity of nature, 1859 1860 1861 1866 1869

natural polity of a district 1872

→ some of the inhabitants of the country undergoing 1859 1860 1861

some of the inhabitants of the country under- going 1866

some of the inhabitants of the country under-going 1869

the 1872

→ kind. 1859 1860 1861 1866 1869

of its existing inhabitants. 1872

↑ 1 blocks not present in 1859 1860 1861 1866 1872; present in 1869

But the effects of natural selection will probably still oftener depend on some few of the inhabitants becoming slowly modified; the mutual relations of the other inhabitants being thus disturbed.

→ On the other hand, 1859 1860 1861 1866

But 1869 1872

→ often only at 1859 1860 1861

generally at only 1866

in effecting changes, at 1869

only at 1872

of the →sea or of the land; and, consequently, the competition between fresh-water productions will have been less severe than elsewhere; new forms will have been more slowly formed, and old forms more slowly exterminated. →And it is in fresh water that we find seven genera of Ganoid fishes, remnants of a once preponderant order: and in fresh water we find some of the most anomalous forms →now known in the world, as the Ornithorhynchus and Lepidosiren, which, like fossils, connect to a certain extent orders now widely separated in the natural scale. These anomalous forms may

~~almost~~

almost

be called living fossils; they have endured to the present day, from having inhabited a confined area, and

thus

~~from~~

from

having

~~thus~~

thus

been exposed to less →severe competition.

To sum →up the circumstances favourable and unfavourable to natural selection, as far as the extreme intricacy of the subject →permits. I

conclude,

conclude

→OMIT that for terrestrial productions a large continental area,

which,

which

will probably

has

undergo

undergone

many oscillations of level, →and which consequently has existed for long periods in a broken condition, has been the most favourable for the production of many new forms of life,

likely

fitted

to endure →long and to spread widely.

Whilst

For

the area →first existed as a continent,

~~and~~

and

the

inhabitants

inhabitants,

→at this period numerous in individuals and kinds,

and will

will

have been subjected to

~~very~~

very

severe competition. When converted by subsidence into large separate islands, there will still

exist

have existed

many individuals of the same species on each

island;

island:

intercrossing on the confines of the range of each →species will thus have been

checked;

checked:

after physical changes of any kind, immigration will

be pre-

have been

vented,

prevented,

so that new places in the polity of each island will have

had to

be filled up by

the modification

modifications

of the old inhabitants; and time will

have been

allowed for the varieties in each to become well modified and perfected. When, by renewed elevation, the islands

shall be

were

re-converted

reconverted

into a continental area, there will again →have been severe competition: the most favoured or improved varieties will

have been

enabled to spread: there will

have been

much extinction of the less improved forms, and the relative proportional numbers of the various inhabitants of the

reunited

renewed

continent will again

have been

changed; and again there will

have been

a fair field for natural selection to improve still further the inhabitants, and thus

to produce

produce

new species.

That natural selection

always

generally

~~will always~~

will always

acts

act

with extreme

slowness,

slowness

I fully admit. →Its action depends on there being places in the →polity of nature, which can be better

filled through

occupied by

→some of the inhabitants of the country undergoing

modifications

modification

of some →kind. The existence of such places will often depend on physical changes, which are generally very slow, and on the immigration of better adapted forms

being

having been

checked. ↑ But the action of natural selection will probably still oftener depend on some

few of

the inhabitants becoming slowly modified; the mutual relations of many of the other inhabitants being thus disturbed. Nothing can be effected, unless favourable variations occur, and variation itself is apparently always a

very

....

slow process. The process will often be greatly retarded by free intercrossing. Many will exclaim that these several causes are amply sufficient

~~wholly~~

wholly

neutralise

stop

the

power

action

of natural selection. I do not believe so. →On the other hand, I do believe that natural selection

will always