Christiansen F B, Frydenberg O
Genetics. 1974 Aug;77(4):765-70. doi: 10.1093/genetics/77.4.765.
Two unlinked polymorphisms of a marine teleost, one in hemoglobin and one in esterase, show parallel clines through Danish waters, while two unlinked phosphoglucosemutase polymorphisms maintain constant gene frequencies. It is argued that the clinal and the constant polymorphisms cannot be accounted for simultaneously by random genetic drift of selectively neutral genes. It is therefore concluded that selection is responsible for at least one of the two classes of geographical patterns, be it the clinal, the constant, or both.
一种海洋硬骨鱼的两个不连锁的多态性，一个在血红蛋白中，一个在酯酶中，在丹麦海域呈现出平行渐变群，而两个不连锁的磷酸葡萄糖变位酶多态性则保持恒定的基因频率。有人认为，渐变群和恒定多态性不能通过选择性中性基因的随机遗传漂变同时得到解释。因此得出结论，选择至少对这两类地理模式中的一种负责，无论是渐变群模式、恒定模式，还是两者皆有。
