Original: In the 2000s , some of the active topics have been the role of gene duplication in the emergence of novel gene function , the extent of adaptive molecular evolution versus neutral drift , and the identification of molecular changes responsible for various human characteristics especially those pertaining to infection , disease , and cognition .
Simplified: In the 2000s , the role of gene duplication , the extent of adaptive molecular evolution versus neutral genetic drift , and the identification of molecular changes responsible for various human characteristics especially those pertaining to infection , disease , and cognition .