On the Origin of Species the publication of "On the Origin of Species" and the bicentenary of Darwin's birth were scheduled for 2009. They celebrated the ideas which "over the last 150 years have revolutionised our understanding of nature and our place within it". In a survey conducted by a group of academic booksellers, publishers and librarians in advance of Academic Book Week in the United Kingdom, "On the Origin of Species" was voted the most influential academic book ever written. It was hailed as "the supreme demonstration of why academic books matter" and "a book which has changed the way we think about everything".
On the Origin of Species larvæ of ichneumonidæ feeding within the live bodies of caterpillars, —not as specially endowed or created instincts, but as small consequences of one general law, leading to the advancement of all organic beings, namely, multiply, vary, let the strongest live and the weakest die. Chapter VIII addresses the idea that species had special characteristics that prevented hybrids from being fertile in order to preserve separately created species. Darwin said that, far from being constant, the difficulty in producing hybrids of related species, and the viability and fertility of the hybrids, varied greatly, especially among plants. Sometimes what were widely considered