There also may be practical obstacles.Some worry that there could be unintended consequences, in part because our understanding of the genome, while growing, is not even close to complete.Writing in Time magazine, Venter, who helped lead the first successful effort to sequence the human genome, warns that “we have little or no knowledge of how (with a few exceptions) changing the genetic code will effect development and the subtlety associated with the tremendous array of human traits.” Venter adds: “Genes and proteins rarely have a single function in the genome and we know of many cases in experimental animals where changing a ‘known function’ of a gene results in developmental surprises.”

A BETTER BRAIN?For many transhumanists, expanding our capacities begins with the organ that most sets humans apart from other animals: the brain.Right now, cognitive enhancement largely involves drugs that were developed and are prescribed to treat certain brain-related conditions, such as Ritalin for attention deficit disorder or modafinil for narcolepsy.