Last and First Men points to the riddle of human evolution, but then leaves it in limbo. The issue here is to first stop darwinian logic in its tracks. We must suspect that the Darwin paradigm persists because powerful entities leave open the options of mass genocide to create a new species. Unaware that the theory is false, the temptation of mass natural selection lurks in the background.
The ‘macro’ effect depicted in LFM is reminder of that it is impossible to induce speciation by artificial genetic manipulation.