Since Alchian and Friedman firstly put forward market selection hypothesis in 1950s,the argument to this question has never been stopped.
正因如此,自Alchian和Friedman提出"市场选择假说"以来,对该问题的争论就从未停止过。
Several main hypotheses have been put forward to explain the evolutionary mechanism of color polymorphism in birds, including Disruptive Selection Hypothesis; Apostatic Selection Hypothesis etc.