STANDARD EVOLUTIONARY THEORY (SET). “New variation arises through random genetic mutation; inheritance occurs through DNA; and natural selection is the sole cause of adaptation, the process by which organisms become well-suited to their environments. In this view, the complexity of biological development — the changes that occur as an organism grows and ages — are of secondary, even minor, importance.”
http://www.nature.com/news/does-evolutionary-theory-need-a-rethink-1.16080