In the striking final chapter of this book, and further developed in several essays since, Franco Moretti proposes a theory of literary evolution inspired by Charles Darwin. As is well known, Darwin's theory of `natural selection' has two key components: first, it postulates that change is random, more prone to failure than to success, and not the unfolding of a teleological process progressing towards some final form of perfection (humans are not more perfect than the humanoids they evolved from); second, it postulates that only those changes which give the creature a reproductive advantage in a given set of external conditions survive (survival of the fittest means survival of the fastest reproducer). Adapting this to the needs of literary history, Moretti renders `natural selection' as follows: (1) aesthetic variation is the product of chance; and (2) the literary marketplace determines which formal variations survive. In later works, Moretti brings in `world-systems' theory to account for the peculiarities of the market, thus departing from his initial quite strict focus on Darwin, but nevertheless maintains the original evolutionary model conceived here. The other striking piece in this work is the essay on Dracula and Frankenstein -- Moretti argues quite brilliantly that these novels reflect two different perspectives on apital -- that of owners and that of employers.