Islands are paradise for biologists – a microcosm. With their discrete boundaries and isolation, they represent geographic areas where the process of evolution may be explored. Biogeography, especially island biogeography is a fascinating area of study. It links ecology, geology, evolution, climatology, geography, and biology. David Quammen in his book, The Song of the Dodo, describes, “Island Biogeography, I am happy to report, is full of cheap thrills….There are giants, dwarfs, crossover artists, nonconformists of every sort…a catalogue of quirks and superlatives.” Observations of life forms on islands by two giants from the world of biology – Alfred Wallace with his extensive work at Malay Archipelago (Indonesia as we now know it) and Charles Darwin with observations from the Galapago Islands – were responsible for the path breaking evolutionary theory, “Origin of Life.” Alfred Russel Wallace, Charles Darwin, and Joseph Hooker, have not remained mere biogeographers cataloguing biodiversity but have demonstrated that biologists are also thinkers, philosophers!
We hear much about the creatures of Galapagos and Maldives and other islands. Most of the news from our own Andaman and Nicobar Islands or Lakshadweep is only about tourism. Andaman and Nicobar Islands, like other islands across the globe, are hosts to animals and plants that are not found elsewhere. Organisms that inhabit specific geographic regions, and are not found in any other similar geographic regions are called endemic species. They should not be confused with indigenous or native species which can survive in similar geographic regions across the globe. The opposite of endemic species is cosmopolitan species – those which are distributed worldwide. For example,the common house gecko native to Southeastern Asia is almost a cosmopolitan lizard. But a specific species of gecko called Gekko verreauxi is found only in Andaman and Nicobar Islands. The latter is therefore endemic to these islands.
The author is a consultant for science and environment education. She can be reached at [email protected].