Digital SAT Reading and Writing Practice Question #461

In evolutionary biology, the Baldwin effect posits that phenotypic plasticity—an organism’s ability to alter its physical traits in response to environmental changes—can initially allow a population to survive abrupt shifts. Over generations, these acquired traits may become genetically encoded, a process known as genetic assimilation. While some evolutionary biologists argue this mechanism accelerates evolutionary divergence by opening new ecological niches, others contend that extreme plasticity actually shields the genotype from natural selection, thereby slowing evolutionary change. A 2023 longitudinal study on stickleback fish populations isolated in novel aquatic environments observed that populations exhibiting high initial plasticity in jaw morphology in response to new prey types actually demonstrated significantly reduced genetic divergence over a 10,000-year modeled span compared to populations with rigid phenotypes. Which statement is best supported by the 2023 study on stickleback fish?