Comparison with 1861 |
|
races may differ much in some one organ from the other races of the same species, yet the
other
parts of the organisation will always be found in some degree different. Professor Bronn likewise asks with striking effect how, for instance in the mouse or hare genus,
natural selection will natural selection will 1861 |
can natural selection 1866 |
account for the several species (descended, I may remark, from a parent of unknown character) having longer or shorter tails, longer or shorter ears, and fur of different colours; how
will
it account for one species of plant having pointed and another species
obtuse
leaves? I can give no definite answer to such questions; but I might ask in return, were these differences, on the doctrine of independent creation, formed for no purpose? If of use, or if due to correlation of growth, they could assuredly be formed through the natural preservation of such useful or correlated variations. I believe in the doctrine of descent with modification, notwithstanding that this or that particular change of structure cannot be accounted for, because this doctrine groups together and explains, as we shall see in the
latter
chapters, many general phenomena of nature. |
|
A distinguished botanist, Mr. H. C. Watson, believes that I have overrated the importance of the principle of divergence of character (in which, however, he apparently believes), and that convergence of character, as it may be called, has likewise played a part. This is an intricate subject which need not be here discussed. I will only
say
that if two species of two closely allied genera produced a number of new and divergent species, I can believe that these new forms might sometimes approach each other so closely that they would for
convenience convenience 1861 | convenience' 1866 |
sake be classed in the same new genus, and thus two genera would converge into one; but from the strength of the principle of inheritance, it
|
races may differ much in some one organ from the other races of the same species, yet the
remaining
parts of the organisation will always be found in some degree different. Professor Bronn likewise asks with striking effect how, for instance in the mouse or hare genus,
can natural selection can natural selection 1866 |
natural selection will 1861 |
account for the several species (descended, I may remark, from a parent of unknown character) having longer or shorter tails, longer or shorter ears, and fur of different colours; how
can
it account for one species of plant having pointed and another species
blunt
leaves? I can give no definite answer to such questions; but I might ask in return, were these differences, on the doctrine of independent creation, formed for no purpose? If of use, or if due to correlation of growth, they could assuredly be formed through the natural preservation of such useful or correlated variations. I believe in the doctrine of descent with modification, notwithstanding that this or that particular change of structure cannot be accounted for, because this doctrine groups together and explains, as we shall see in the
later
chapters, many general phenomena of nature. |
|
A distinguished botanist, Mr. H. C. Watson, believes that I have overrated the importance of the principle of divergence of character (in which, however, he apparently believes), and that convergence of character, as it may be called, has likewise played a part. This is an intricate subject which need not be here discussed. I will only
remark
that if two species of two closely allied genera produced a number of new and divergent species, I can believe that these new forms might sometimes approach each other so closely that they would for
convenience' convenience' 1866 | convenience 1861 |
sake be classed in the same new genus, and thus two genera would converge into one; but from the strength of the principle of inheritance, it
|