I find in the domestic duck that the bones of the wing weigh less and the bones of the leg more, in proportion to the whole skeleton, than do the same bones in the wild duck; and this change may be safely attributed to the domestic duck flying much less, and walking more, than its wild parents.
Charles DarwinI think it can be shown that there is such an unerring power at work in Natural Selection, which selects exclusively for the good of each organic being.
Charles DarwinWhen the sexes differ in beauty, in the power of singing, or in producing what I have called instrumental music, it is almost invariably the male which excels the female.
Charles DarwinBesides love and sympathy, animals exhibit other qualities connected with the social instincts which in us would be called moral.
Charles DarwinThe instruction at Edinburgh was altogether by lectures, and these were intolerably dull, with the exception of those on chemistry.
Charles DarwinI have just finished my sketch of my species theory. If as I believe that my theory is true & if it be accepted even by one competent judge, it will be a considerable step in science. I therefore write this, in case of my sudden death, as my most solemn & last request, which I am sure you will consider the same as if legally entered in my will, that you will devote 400£ to its publication & further will yourself, or through Hensleigh [Wedgwood], take trouble in promoting it.
Charles Darwin