 At the same time, things were progressing rather differently in Europe, where ethological approaches to animal behavior were more dominant.  Ethology is part natural history with an emphasis on fieldwork and part experimental science conducted on captive animals, reflecting the different styles of its two seminal figures, Konrad Lorenz and Niko Tinbergen (see Burkhardt 2005). Initially, “innate” behaviors were the central focus of Lorenz's work. According to Lorenz, it is the investigation of innate behaviors in related species that puts the study of animal behavior on a par with other branches of evolutionary biology, and he demonstrated that it was possible to derive the phylogenetic relations among species by comparing their instinctive behavioral repertoires (Lorenz 1971a). In pursuing this direction, Lorenz and Tinbergen explicitly sought to distance ethology from the purposive, mentalistic, animal psychology of Bierens de Haan and the lack of biological concern they detected in American comparative psychology (see Brigandt 2005).  Like Lloyd Morgan, the ethologists rejected Romanes anecdotal approach, but they also criticized Lloyd Morgan's subjectivist approach.