[T]he voyages of exploration made use of a new vessel, the caravel. Caravels were much smaller than the largest European ships and the Chinese junks Zheng He had used to explore the Indian Ocean early in the fifteenth century.

Petronius calleth this paſſion [i.e., jealousy] amantium furioſam æmulationem, a furious emulation, and their ſymptomes are well expreſſed by Sʳ Ieffrey Chaucer in his firſt Canterbury tale. It will make the neareſt & deareſt friends fall out; they will endure al other things to be common, goods, lands, moneyes, participate of all other pleaſures, and take in good part any diſgraces, iniuries in another kind, but as Propertius well deſcribes it in an Elegie of his, in this they will ſuffer nothing, have no corriuals.

...if you consider any man a friend whom you do not trust as you trust yourself, you are mightily mistaken and you do not sufficiently understand what true friendship means.

Some evolutionary theorists stress that cultural innovation allows human beings to overcome the blind stumblings of natural selection: we deliberately solve a problem and pass on that solution to our descendants, who improve on it in turn.