Source google image: https://ai2-s2-public.s3-us-west-2.amazonaws.com/figures/2017-08-08/66e09cca9eb7dc966ed5b1bb8d2dacfaaf18a622/5-Figure5-1.png
N reproductive isolation
Source google image: https://ai2-s2-public.s3-us-west-2.amazonaws.com/figures/2017-08-08/66e09cca9eb7dc966ed5b1bb8d2dacfaaf18a622/5-Figure5-1.png