A new paper published in the journal Science argues that traits that are highly variable and evolve quickly, over short time scales, are often the same ones that shape the direction of long-term evolution of new species. School of Biological Sciences Assistant Professor James Stroud, who was not involved in the research, says the study provides a fascinating insight: “As selection changes through time to chase new optima, the genetic variation of traits under selection may increase from this evolutionary back and forth,” he says. “This additive genetic variance, termed evolvability, is a window into evolution’s past.”