These racial histories are the most important evidence available to the
student of natural selection in man. The conclusion to be drawn from
them seems plain. Natural selection, which has in the past never had an
opportunity to act upon the Negro race through tuberculosis, is now
engaged in hastening, at a relatively rapid rate, the evolution of this
race toward immunity from death by tuberculosis. The evolution of the
white race on this line is, as the figures show, going on
simultaneously, but having begun centuries earlier, it is not now so
rapid. The weakest white stocks were cut off hundreds of years ago, in
Great Britain or Europe; those of the black race are only now going.
Despite all the efforts of medicine and sanitation, it is likely that
the Negro death-rate from phthisis will continue high for some years,
until what is left of the race will possess a degree of resistance, or
immunity, not much inferior to that of the whites among whom they live.
The blacks in North America now must be already more resistant than
their ancestors; the mulattoes descended of normal healthy unions should
be more resistant than the pure Negroes, although no statistics are
available on the point; but were a new immigration to take place from
Africa to-day, and the immigrants to be put into villages with their
Americanized brethren, the high death-rate would result.
Pages:
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227