and (ii) the derived state of the breeding (rather than winter) ecological niches of each species., The evolution of migration has long been considered complex and recent work has demonstrated additional complexity: some species follow the same ecological conditions throughout…

Although some excellent articles about Lyell's work have been published, they do not explicitly deal with Lyell's biogeographical conceptions. The purpose of this paper is to analyse Lyell's biogeographical model in terms of its own internal structure. Lyell tried to…