The process described concerns the role of microbial disease in the conquering of people-groups.
[4] An evidence presented to support the hypothesis involves the manner diseases associated with Europeans were rebuffed in their forays into disease-experienced countries such as China and Japan.
[4] The first people-group fully wiped out due to European expansion (with the possible exception of the Arawaks) was the Guanches of the Canary Islands.
McNeill's Law would place the deciding factor squarely on the introduction of deadly diseases and parasites from the mainland to the previously geographically isolated islanders.
[citation needed] This is the likely explanation, as what records still exist show numerous deaths by disease on the islands and a declining birth rate, leading eventually to the almost complete end of the Guanches as a race.