Constant Quote by Jean-Baptiste Lamarck

That the variability of an organism to a certain extent is a constant and certain condition of life we admit, otherwise there would be…

— Richard Owen

As in all of biology, comparative studies showing differences among species are often helpful for a better understanding of the basic mechanisms; with all…

— John Tyler Bonner

The fundamental problem in the origin of species is not the origin of differences in appearance, since these arise at the level of the…

— David Lack

“It has already been stated that various parts in the same individual, which are exactly alike during an early embryonic period, become widely different…

— Charles Darwin

I have called this principle, by which each slight variation, if useful, is preserved, by the term of Natural Selection.

— Charles Darwin

If a species is diverse, it can survive and prosper. If a species is homogeneous, it is vulnerable.

— Richard Koch

There is behavioral ecology, which looks closely at the difference different ecologies make to behavior and other features of animals and humans. There's evolutionary…

— Brian Boyd

Mere chance ... alone would never account for so habitual and large an amount of difference as that between varieties of the same species.

— Charles Darwin

The facts of microevolution [change within the species] do not suffice for an understanding of macroevolution [theorized change from one species to another].

— Richard Goldschmidt

“As the species of the same genus usually have, though by no means invariably, much similarity in habits and constitution, and always in structure,…

— Charles Darwin

“In Darwin's time no serious attempt had been made to examine the manifestations of variability. A vast assemblage of miscellaneous facts could formerly be…

— William Bateson

I do not deny certain kinds of biological differences. But I always ask under what conditions, under what discursive and institutional conditions, do certain…

— Judith Butler