Associate Professor Li Lingling of the zoology department at NTU observes that in zoology there is the theory of so-called "keystone species," whereby a species 'existence and numbers affects the populations of other species. Such keystone species include the insects and bats which pollinate flowers, or the organisms which break down dead matter and so form a link in the cycle of nutrients.
台大動物系副教授李玲玲指出，動物學上有所謂「關鍵物種」理論，意指某一物種的存在與否、族群大小，會影響其他物種的數量，例如傳花受粉的昆蟲、蝙蝠，或聯繫養分循環的分解者。