Origin of Species Variorum

→ 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

→ OMIT 1861 1866 1869 1872

it may be said, 1859 1860

→ selection. 1861 1866 1869

selection. The tendency to reversion may often check or prevent the work; but as this tendency has not prevented man from forming by selection numerous domestic races, why should it prevail against natural selection? 1872

→ has 1861 1866

may often check or prevent the work; but as this tendency has 1869

→ creating innumerable hereditary races in the animal and vegetable kingdoms, 1861 1866

forming by selection numerous domestic races, 1869

→ have stopped the process of 1861 1866

prevail against 1869

→ 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

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

→OMIT 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. Unless favourable variations be inherited by some at least of the offspring, nothing can be effected by natural →selection. Non-inheritance of any new character is, in fact, the same thing as reversion to the character of the grandparents or more remote ancestors; and no doubt the tendency to reversion may often have checked or prevented the action of natural selection; but its importance has been greatly exaggerated by some writers.

The

If the

tendency to reversion →has not prevented man from →creating innumerable hereditary races in the animal and vegetable kingdoms, why should it →have stopped the process of natural selection?

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.