Summary Of My Island Life By Luke Harmon

In his essay, “My Island Life,” Luke Harmon discusses the importance of islands and how they have been used by evolutionary biologists to study evolution and diversification on Earth. Harmon focuses on biogeography and on how different species are distributed across the Earth. Harmon also makes a point to mention how human introduction of invasive species is rapidly causing islands around the Earth to become uniform and less diversified. Harmon’s research on the evolutionary history of lizards found on two separate regions of Islands begins with the influence of Wallace’s line, discovered by Alfred Russel Wallace. This line is described as invisible boundaries that separate Earth into provinces, and these provinces contain distinct species. Wallace noticed that the physical influences and conditions did not change across the line, but the species inhabiting it did. With Wallace’s discoveries in mind, Harmon hypothesizes that by studying the diversification and evolutionary history of two different lizard species, anoles and day geckos, will show how evolution can be predictable.

Although the four anole ecomorphs are almost identical in appearance and inhabit the four islands, they are not closely related. The lizards on each island descended all from a few original species that later evolved and differentiated into a large number of descendants. It can be observed that in all four species, their ancestral lineages have evolved independently but evolving the same traits for the habitat they were in. Harmon explains how this can show the predictability of evolution on a longer time