我们或许会认为进化导致那些只为自身利益考虑的个体 — — 以及他们的亲族 — — 才能被筛选留存下来，因为携带这类特性的基因更可能开枝散叶。
We might think that evolution leads to the selection of individuals who think only of their own interests, and those of their kin, because genes for such traits would be more likely to spread.