According to Li Ling-ling, an assistant professor of zoology at National Taiwan University, the different physical structures and habits that animals of different species develop as a result of evolution make it difficult for them to mate together and reproduce.
畜產與野生有別台灣大學動物系副教授李玲玲表示，由遺傳學上來看，生物長久以來自然演化結果，各種動物有其特有的習性、構造… …，不同種動物不太可能自然交配、繁殖。