This effectively means that populations of organisms must have reached a certain measurable level of difference to be recognised as subspecies. Dean Amadon proposed in 1949 that subspecies would be defined according to the seventy-five percent rule which means that 75% of a population must lie outside 99% of the range of other populations for a given defining morphological character or a set of characters. The seventy-five percent rule still has defenders but other scholars argue that it should be replaced with ninety or ninety-five percent rule.
৭৫% নিয়ম বলে একটি জনসংখ্যার কতজন অন্যান্য জনসংখ্যার সীমার বাইরে থাকতে হবে একটি সংজ্ঞায়িত চরিত্রের সেট?
99%