Explain why island biogeography, originally focused on actual islands, is now used to study other areas such as parks surrounded by human habitation and mountains surrounded by deserts.

Island biogeography, originally focused on island chains, applies well to isolated habitats like urban parks or mountains due to similarities in isolation and ecological boundaries. These habitats can show adaptive radiation and species diversity, offering insights into ecology and evolution.

Explanation:

Island biogeography is the study of life on island chains and how their geography interacts with the diversity of species found there. Initially focused on actual islands, the principles of island biogeography make sense when applied to other isolated habitats like parks surrounded by urban areas or mountains encircled by deserts.

The concept of adaptive radiation—where a single species evolves into several different forms that occupy different ecological niches—is a cornerstone of island biogeography. This can also occur in non-island 'islands', exhibiting similar patterns of speciation and biodiversity due to geographic isolation and ecological pressures. Therefore, island biogeography offers insights into the broader principles of ecology and evolutionary biology.