P. David Polly is a vertebrate palaeontologist at Indiana University, Bloomington. He studies the evolution of mammals and other vertebrates in the fossil record, including trait-based studies of community response to environmental change, geometric morphometric analysis of evolution and morphology, phylogenetics, biogeography, and speciation on regional and continental geographic scales.
Jan Zima is a Senior Scientist at the Institute of Vertebrate Biology, Academy of Sciences of the Czech Republic, Prague and Professor of Zoology at the Department of Zoology, Univerzita Karlova, Prague. He has studied chromosomal variation in various species of mammals and other vertebrates, and has attempted to imply cytogenetic findings to biodiversity, systematic and phylogenetic issues.