相互亲缘 meaning in English

reciprocal relative

In considering the origin of species , it is quite conceivable that a naturalist , reflecting on the mutual affinities of organic beings , on their embryological relations , their geographical distribution , geological succession , and other such facts , might come to the conclusion that species had not been independently created , but had descended , like varieties , from other species
关于物种起源，完全可以想像得到的是，一位博物学者如果对生物的相互亲缘关系、胚胎关系、地理分布、地质演替以及其他这类事实加以思考，那么他大概会得出如下结论：物种不是被独立创造出来的，而和变种一样，是从其他物种传下来的。