Questions 6-10 refer to the following passage.
The following passage is an excerpt from the conclusion to the first edition of On The Origin of Species by Means of Natural Selection, or The Preservation of Favoured Races in The Struggle for Life, the full title of Charles Darwin’s hugely influential book which was published in 1859. Spelling and punctuation have been modernized and Americanized.
I have now recapitulated the chief facts and considerations
which have thoroughly convinced me that species have changed and
are still slowly changing by the preservation and accumulation of
Line successive slight favorable variations. Why, it may be asked,
(5) have all the most eminent living naturalists and geologists
rejected this view of the mutability of species? It cannot be
asserted that organic beings in a state of nature are subject to
no variation; it cannot be proved that the amount of variation in
the course of long ages is a limited quantity; no clear
(10) distinction has been, or can be, drawn between species and
well-marked varieties. It cannot be maintained that species when
intercrossed are invariably sterile, and varieties invariably
fertile, or that sterility is a special endowment and sign of
creation. The belief that species were immutable productions was
(15) almost unavoidable as long as the history of the world was
thought to be of short duration; now that we have acquired some
idea of the lapse of time, we are too apt to assume, without
proof, that the geological record is so perfect that it would
have afforded us plain evidence of the mutation 1 of species, if
(20) they had undergone mutation.
But the chief cause of our natural unwillingness to admit
that one species has given birth to other and distinct species is
that we are always slow in admitting any great change of which we...