Towards a unified vision on animal navigation.

The study of animal navigation is a complex and fertile field of research: several questions regarding how animals relate to external stimuli, integrating them to perform their everyday movement routine, have been or are being addressed in different organisms and taxa, both from the behavioural and the neuronal activity point of view. Several invertebrate model organisms are the object of studies aimed at unravelling how they navigate and their ability to precisely return to a starting point, and also how navigational information is communicated to conspecifics when precise social structures are present. Also, vertebrates are studied because of the interest in their orientation abilities while migrating, homing over impressive distances, and to study exploration, orientation, and space recognition. Last, research on the navigation capabilities of humans pursues a better understanding of the neural architecture involved in these processes, in the remarkable effort to find answers and possible solutions to impairments, lesions, and diseases. However, an "all-inclusive" vision of navigation still appears to be in its embryonic state: a better perspective could (and should) shift from a paradigm where single research teams are centered on studying navigation in a single genus or species towards a more comprehensive evolutionary-centered view, searching systematically for behavioural analogies, and possibly for homologies in neural architecture between different taxa. In this review, we introduce examples of relevant topics in animal navigation from distinct animal groups, highlighting the similar approaches of those studies, and why, in our opinion, this research field could profit from a "new" perspective.