"The tribe of Hapaa," he writes, "is said to have numbered some four hundred when the small-pox came and reduced them by one-fourth. Six months later a woman developed tubercular consumption; the disease spread like fire about the valley, and in less than a year two survivors, a man and a woman, fled from the newly-created solitude.... Early in the year of my visit, for example, or late the year before, the first case of phthisis appeared in a household of 17 persons, and by the end of August, when the tale was told me, one soul survived, a boy who had been absent at his schooling."
In Tasmania is another good illustration of the evolution of a race proceeding so rapidly as to be fatal to the race. When the first English settled on the island, in 1803, the native population consisted of several thousand. Tuberculosis and many other new diseases, and, most of all, alcohol, began to operate on the aborigines, who were attracted to the settlements of the whites. In a quarter of a century there were only a few hundred left. Many, of course, had met violent deaths, but an enlightened perusal of any history of the period,13 will leave no doubt that natural selection by disease was responsible for most of the mortality. By 1847 the number of native Tasmanians was reduced to 44, who were already unmistakably doomed by alcohol and bacteria. When the last full-blood Tasmanian died in 1876, a new chapter was written in the story of the modern evolution of the human race.
No such stories are told about the white settlements on this continent, even before the days of quarantine and scientific medicine. There is no other adequate explanation of the difference, than that the two races have evolved to a different degree in their resistance to these diseases. It is easily seen, then, that man's evolution is going on, at varying rates of speed, in probably all parts of the human race at the present time.