Atavism
EVOLUTIONARY THROWBACK, SUCH AS TRAITS REAPPEARING THAT HAD DISAPPEARED GENERATIONS BEFORE
Atavistic; Evolutionary throwback; Evolutionary throwbacks; Evolutionary throw-back; Evolutionary throw-backs; Evolutionary throw back; Evolutionary throw backs; Atavisms
In biology, an atavism is a modification of a biological structure whereby an ancestral genetic trait reappears after having been lost through evolutionary change in previous generations. Atavisms can occur in several ways; one of which is when genes for previously existing phenotypic features are preserved in DNA, and these become expressed through a mutation that either knocks out the dominant genes for the new traits or makes the old traits dominate the new one.