'Wherever the European has trod, death seems to pursue the aboriginal.' So wrote Charles Darwin in 1836. Though there has been considerable discussion concerning their precise demographic impact, reflected in the articles here, there is no doubt that the arrival of new diseases with the Europeans (such as typhus and smallpox) had a catastrophic effect on the indigenous population of the Americas, and later of the Pacific. In the Americas, malaria and yellow fever also came with the slaves from Africa, themselves imported to work the depopulated land. These diseases placed Europeans at risk too, and with some resistance to both disease pools, Africans could have a better chance of survival. Also covered here is the controversy over the origins of syphilis, while the final essays look at agricultural consequences of the European expansion, in terms of nutrition both in North America and in Europe.