Reevaluation of zoogeographical divisions and their driving factors - an insight from terrestrial vertebrates

Biogeographical division refers to dividing a given area into identifiable biogeographical realms and their corresponding boundaries, based on the geographical distribution of selected biological taxa. Previous studies have generally lacked clustering analyses of faunal compositional similarity across multiple geographical units and have rarely assessed how ecological factors shape zoogeographical divisions across different spatial scales. Here, we reevaluated the world’s zoogeographical realms using the multivariate similarity clustering analysis (MSCA) method based on the genus-level distributional data for terrestrial vertebrates, and then tested the relative importance and statistical significance of ecological factors on the formation of realms and their boundaries using generalized linear model and hierarchical generalized linear model, respectively. The results showed that: 1) totally six world’s zoogeographical realms, the Afrotropical, Australian, Nearctic, Neotropical, Oriental, and Palearctic realms had been delineated, and the Oriental–Australian boundary was more consistent with the Weber Line; 2) current climatic temperature and vegetation influenced the formation of zoogeographical realms, whereas the effects of current climatic precipitation, past climate, and tectonic movement varied among realms; 3) tectonic movement and precipitation seasonality of current climate significantly influenced the formation of boundaries between realms; and 4) the positions of zoogeographical boundaries between realms were dynamic and taxon-dependent. Our findings were expected to provide new insights into biogeographical researches.