Certify Teacher Science Practice Exam 2026 - Free Practice Questions and Study Guide for Science Certification

Genes that are responsible for new traits enhancing survival are subject to natural selection, a core principle of modern evolutionary theory. When an organism possesses a trait that improves its chances of surviving and reproducing in its environment, the alleles (gene variants) associated with that trait will likely be passed down to subsequent generations. As a result, those favorable traits increase in frequency within the population over time.

This process occurs because organisms with advantageous traits are more likely to survive long enough to reproduce, passing on the genes corresponding to those traits. Consequently, the beneficial genes become more common in the gene pool, contributing to the overall adaptation of the species to its environment. This shift in gene frequency is a fundamental mechanism through which evolution occurs, illustrating how beneficial traits become more prevalent as they enhance survival and reproductive success.