I am new to phylogenetic comparative methods and want to evaluate a hypothesis that proposes a link between the presence/absence of a phenotypic character with the number of chromosomes. I'm aware of models such as BiChrom, but what I want is the inverse. That is, these models evaluate hypotheses of whether or not rates of gain and loss among chromosomes are affected by the presence or absence of a phenotypic trait. I'm interested in whether the number of chromosomes affects the presence/absence of a phenotypic trait. Any advice or literature would be greatly appreciated.