Teranesia by Greg Egan
TERANESIA is set in 2012. Prabir Suresh is nine years old and the son of two scientists specialising in entomology. They live on an otherwise uninhabited island in a remote part of the Indonesian peninsula. The island has no real name, but Prabir calls it Teranesia and populates it with imaginary creatures even stranger than the evolutionarily puzzling butterflies that his parents are studying. His world falls apart when civil war kills his parents and leaves him to look after his infant sister. Eighteen years later, rumours of bizarre new species of plants and animals being discovered in the peninsula that was their childhood home draw Prabir's sister back to the island - Prabir cannot bear for her to have gone out alone and he follows, persuading a pharmaceutical researcher to take him along as a guide. Prabir's sister and the researcher succeed in isolating the gene responsible for these new mutations - the T-gene promises that any form of life on Teranesia will out compete tho se in the outside world. When Prabir himself is infected with a virus carrying this T-gene the bulk of the scientists on Teransia want him dead - the ultimate quarantine that will safeguard humanity as they know it.