Origin of Species Variorum

→ to Natural Selection. — 1860 1861

to Natural Selection .— 1859

to Natural Selection. 1866

for the production of new forms through Natural Selection. 1869

for the production of new forms through Natural Selection. 1872

→ inheritable and diversified variability is favourable, but I believe mere 1859 1860

variability will evidently be favourable for the work of natural selection, but mere 1861 1866

variability, under which term 1869 1872

→ suffice for the work. 1859 1860

probably suffice. 1861 1866

are always included, will evidently be favourable. 1869 1872

→ for the appearance within any given period of profitable variations, 1859 1860 1861 1866

for the appearance of profitable variations within any given period, 1869

within any given period for the appearance of profitable variations, 1872

→ it may be said, 1859 1860

OMIT 1861 1866 1869 1872

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

Unless favourable variations be inherited by some at least of the offspring, nothing can be effected by natural selection.

→ man's 1859 1860 1861 1866

the case of 1869 1872

→ free intercrossing will wholly stop 1859 1860 1861 1866 1869

if the individuals be allowed freely to intercross, 1872

→ work. 1859 1860 1861 1866 1869

work will completely fail. 1872

→ a large amount of crossing with inferior animals. 1859 1860 1861 1866 1869

that there is no separation of selected individuals. 1872

→ as might be, natural selection will always tend to preserve 1859 1860 1861 1866

natural selection will always tend to preserve 1869

OMIT 1872

→ so as better to fill up the unoccupied place. 1859 1860 1861 1866 1869

will tend to be preserved. 1872

→ then if natural selection be modifying and improving a species in the several districts, there will be intercrossing with the other individuals of the same species on the confines of each. 1860

then 1859 1861

then, 1866 1869 1872

Circumstances

favourable

→ to Natural Selection. —

This is an extremely intricate subject. A

great

large

amount of →inheritable and diversified variability is favourable, but I believe mere individual differences →suffice for the work. A large number of individuals, by giving a better chance →for the appearance within any given period of profitable variations, will compensate for a lesser amount of variability in each individual, and is, I believe,

a highly

an extremely

important element of success. Though

Nature

nature

grants

long

vast

periods of time for the work of natural selection, she does not grant an indefinite period; for as all organic beings are

striving

striving,

→it may be said, to seize on each place in the economy of nature, if any one species does not become modified and improved in a corresponding degree with its competitors, it will

~~soon~~

soon

be exterminated. ↑

In →man's methodical selection, a breeder selects for some definite object, and →free intercrossing will wholly stop his →work. But when many men, without intending to alter the breed, have a nearly common standard of perfection, and all try to

procure

get

and breed from the best animals,

~~much~~

much

improvement

~~and modification~~

and modification

surely but slowly

follows

from this unconscious process of selection, notwithstanding →a large amount of crossing with inferior animals. Thus it will be

under

nature; for within a confined area, with some place in

the natural

its

polity not

perfectly

occupied,

occupied

→as might be, natural selection will always tend to preserve all the individuals varying in the right direction, though in different degrees, →so as better to fill up the unoccupied place. But if the area be

very large,

large,

its several districts will almost certainly present different conditions of life; and →then if natural selection be modifying and improving a species in the several districts, there will be intercrossing with the other individuals of the same species on the confines of each. And in