In a recent interview with Piers Morgan, Republican presidential candidate Herman Cain stated that it is his belief that homosexuality is a "sin" as well as a "choice." When Piers Morgan pressed further, asking Cain if he really believed this, Cain responded by demanding scientific evidence to the contrary. While the science surrounding sexual orientation is complex, a 2006 study showed a correlation between male homosexuality and the number of older male (biological) siblings. In 2007, researchers discovered that by altering a specific gene in fruit flies they could effectively make the flies bisexual. In 2008 it was reported that a gene found in gay men caused an increase in fertility when present in women, which may partly explain the genetic components of male homosexuality as well as explain why homosexuality has survived natural selection. And just last year, a study showed that the deletion of a specific gene in female mice during the embryo stage effectively turned the mice into lesbians. In other words, science is increasingly demonstrating that same-sex attraction is far from a choice, in spite of Herman Cain's objections.