translation.en: So, what he found is that in all cases of thumb mutations, instead of having a thumb, you would either get another opposable thumb, or you would get four fingers.
translation.zh: 所以，他发现在所有拇指突变的案例中， 与仅有一个拇指所不同地， 那些不是长出个反方向的拇指， 要不就是四个手指。