Moreover, volcanic archipelagos often form sequentially, generating a series of islands of different ages. Thus, the ages of these islands can often be estimated accurately, making it possible to set age limits for endemic taxa. Second, given sufficient elevation there is a high diversity of ecological zones in a very small geographic area, which produces a wide variety of habitats for new colonizers. Third, islands are isolated from the continental sources of the flora and fauna. This geographic isolation provides immediate spatial isolation and cuts reproductive ties between founder and progenitor populations.
Most oceanic islands have an exceptionally diverse and highly endemic flora and fauna.
The most alarming statistic about island biota is that they have the highest incidence of endangered species. One third of the endangered plants in the world occur on volcanic islands. Thus, there is a immediate need to gather biological data on island endemics to make informed decisions about conserving this evolutionarily significant component of the world's biota. During the past three years the primary focus of my lab has been directed toward examining the origin, evolution, and conservation biology of endemic plants from the five archipelagos that comprise Macaronesia. These archipelagos have several distinctive features that make them interesting systems for understanding the origin and evolution of island floras and faunas.