Origin of Species Variorum

→ SELECTION. 1859 1860 1861 1866

SELECTION; OR THE SURVIVAL OF THE FITTEST. 1869 1872

→ Natural 1859 1860 1861 1866

the results of Natural 1869 1872

→ beings. 1859 1860

beings— Advance in organisation— Low forms preserved— Objections considered— Indefinite multiplication of species— Summary. 1861

beings — Advance in organisation— Low forms preserved— Objections considered— Indefinite multiplication of species— Summary. 1866

beings— Advance in organisation— Low forms preserved— Objections considered— Uniformity of certain characters due to their unimportance and to their not having been acted on by Natural Selection— Indefinite multiplication of species— Summary. 1869

beings— Advance in organisation— Low forms preserved— Convergence of character— Indefinite multiplication of species— Summary. 1872

→ discussed too briefly 1859 1860 1861 1866

briefly discussed 1869 1872

→ it be borne in mind in what an 1859 1860 1861 1866

the 1869 1872

→ strange peculiarities 1859 1860 1861 1866

peculiar variations in 1869

slight variations and individual differences occurring in 1872

→ vary; and how strong 1859 1860 1861 1866

be borne in mind; as well as the strength of 1869 1872

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

But the variability, which we almost universally meet with in our domestic productions, is not directly produced, as Hooker and Asa Gray have well remarked, by man; he can neither originate varieties, nor prevent their occurrence; he can only preserve and accumulate such as do occur; unintentionally he exposes organic beings to new and changing conditions of life, and variability ensues; but similar changes of conditions might and do occur under nature.

CHAPTER IV.

NATURAL →SELECTION.

Natural Selection— its power compared with

mans

man's

selection— its power on characters of trifling importance— its power at all ages and on both sexes— Sexual Selection— On the generality of intercrosses between individuals of the same species— Circumstances favourable and unfavourable to →Natural Selection, namely, intercrossing, isolation, number of individuals— Slow action— Extinction caused by Natural Selection— Divergence of

Character

Character,

related to the diversity of inhabitants of any small area, and to naturalisation— Action of Natural Selection, through Divergence of

Character,

Character

and Extinction, on the descendants from a common parent— Explains the

grouping

Grouping

of all organic →beings.

How

HOW

will the struggle for existence, →discussed too briefly in the last chapter, act in regard to variation? Can the principle of selection, which we have seen is so potent in the hands of man, apply

under

nature? I think we shall see that it can act most

efficiently.

effectually.

Let →it be borne in mind in what an endless number of →strange peculiarities our domestic productions, and, in a lesser degree,

in those

those

under nature, →vary; and how strong the hereditary

tendency.

tendency

~~is.~~

is.

Under domestication, it may be truly said that the whole organisation becomes in some degree plastic. ↑ Let it

also be

borne in mind how infinitely complex and

closefitting

close-fitting

are the mutual relations of all organic beings to each other and to their physical conditions of

life;

life.

Can it, then, be thought improbable, seeing that variations useful to man have undoubtedly occurred, that other variations useful in some way to each being in the great and complex battle of life, should

~~sometimes~~

sometimes

occur in the course of

many successive

thousands of

generations? If such do occur, can we doubt

(remembering

(remem- bering