Origin of Species Variorum

→ the course of ages chanced to arise, and which in 1859 1860 1861 1866

OMIT 1869 1872

→ by specially acting on the reproductive system, causes or 1859 1860 1861 1866

cause or 1869

give a tendency to 1872

→ increases variability; 1859 1860 1861 1866

excite a tendency to vary; 1869

increased variability; 1872

→ of life are supposed to have undergone a 1859 1860 1861 1866

are supposed to have 1869

have 1872

→ profitable variations occurring; and unless 1859 1860 1861 1866 1869

the occurrence of 1872

↑ 2 blocks not present in 1859 1860 1861 1866; present in 1869 1872

Under the term of "variations," it must never be forgotten that mere individual differences are always included. As man can certainly produce a great result with his domestic animals and plants by adding up in any given direction individual differences, so could natural selection, but far more easily, from having incomparably longer time for action.

→ as I believe, 1859 1860

OMIT 1861 1866

→ at her disposal. 1859 1860

for action. 1861 1866

→ to produce 1859 1860 1861 1866 1869

in order that 1872

→ for 1859 1860 1861 1866 1869

should be left, for 1872

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

as long as the being continued under the same conditions of life and profited by similar means of subsistence and defence.

places would have been seized

by intruders. In such

cases,

case,

~~every~~

every

slight

modifications,

modification,

which in →the course of ages chanced to arise, and which in any way favoured the individuals of any

~~of the~~

of the

species, by better adapting them to their altered conditions, would tend to be preserved; and natural selection would

~~thus~~

thus

have free scope for the work of improvement.

We have

good reason

reason

to believe, as

shown

stated

in the first chapter, that

changes

change

in the conditions of

life

life,

→by specially acting on the reproductive system, causes or →increases variability; and in the foregoing

cases

case

the conditions →of life are supposed to have undergone a

changed,

change,

and this would manifestly be favourable to natural selection, by

affording

giving

a better chance of →profitable variations occurring; and unless

such

profitable variations.

profitable variations

Unless such

occur, natural selection can do nothing. ↑ Not

that

that,

→as I believe, any extreme amount of variability is necessary; as man can certainly produce great results by adding up in any given direction mere individual differences, so could

natural selection,

Nature,

but far more easily, from having incomparably longer time →at her disposal. Nor do I believe that any great physical change, as of climate, or any unusual degree of isolation to check

immigra- tion,

immigration,

~~actually~~

actually

necessary →to produce new and unoccupied places →for natural selection to fill up by

~~modifying and~~

modifying and

improving some of the varying inhabitants. For as all the inhabitants of each country are struggling together with nicely balanced forces, extremely slight modifications in the structure or habits of one

species

inhabitant

would often give it an advantage over others; and still further modifications of the same kind would often still further increase the

advantage,

advantage.

↑ No country can be named in which all the native inhabitants are now so perfectly adapted to each other and to the physical conditions under which they live, that none of