Origin of Species Variorum

→ natural and artificial, 1859 1860 1861

those naturally and those artificially produced, 1866 1869 1872

→ is probably 1859 1860 1861

has at some periods probably been 1866 1869 1872

→ the number of species has 1859 1860 1861

species have 1866 1869 1872

been exterminated, either locally or wholly, through

mans

man's

agency. I may repeat what I published in 1845, namely, that to admit that species generally become rare before they become extinct— to feel no surprise at the rarity of a species, and yet to marvel greatly when

the species

ceases to exist, is much the same as to admit that sickness in the individual is the forerunner of death— to feel no surprise at sickness,

but,

but

when the sick man dies, to wonder and to suspect that he died by some

~~unknown~~

unknown

deed of violence.

The theory of natural selection is grounded on the belief that each new variety, and ultimately each new species, is produced and maintained by having some advantage over those with which it comes into

compe- tition;

competition;

and the consequent extinction of

the less-favoured

less-favoured

forms almost inevitably follows. It is the same with our domestic

productions;

productions:

when a new and slightly improved variety has been raised, it at first

generally supplants

supplants

the less improved varieties in the same neighbourhood; when much improved it is transported far and near, like our short-horn cattle, and takes the place of other breeds in other countries. Thus the appearance of new forms and the disappearance of old forms, both →natural and artificial, are bound together. In

~~certain~~

certain

flourishing groups, the number of new specific forms which have been produced within a given time →is probably greater than

the number

that

of the old

specific forms

forms

which have been exterminated; but we know that →the number of species has not gone on indefinitely increasing, at least during the later geological

epochs,

periods,

that,

that

looking to later

times,

times

we may believe that the production of new forms has caused the extinction of about the same number of old forms.

The competition will generally be most severe, as formerly explained and illustrated by examples, between the forms which are most like each other in all respects.