Which of the following are correct: A neutral model predicts that a community structured by interspecific competition should look like: i)potential competitors that coexist in a community should exhibit niche differentiation; ii)this niche differentiation will often manifest itself as morphological differentiation,iii)a community of species will tend to vary along one niche,iv)within a community,potential competitors with little or no niche differentiation should not coexist,so each should tend to occur only where the other is absent