The parasite that causes malaria, though, can only complete its life cycle in normal, round red blood cells.

然而，致疟疾的寄生虫只能在正常的圆形中完成其生命周期。

And that mutation caused a red blood cell that normally looks like this to be made like that.

这种突变致原本正常的形态变成了这样。

Those red blood cells get engulfed by the liver, who helps just try to clean up any messy red blood cells in the system.

这些被肝脏吞噬，肝脏的作用是帮助清理系统中任何不正常的。

Carriers are less susceptible to malaria, because they make some sickled red blood cells, but they make enough normal red blood cells that they aren't negatively affected by sickle cell anemia.

携带者不易感染疟疾， 因为他们会产生一些镰状，但他们会产生足够多的正常， 因此不会受到镰状性贫血的负面影响。