The Drifty Gene Hypothesis proposes that genetic variations in a population can occur by chance due to the random fluctuations in the frequency of alleles over time. This hypothesis is also known as the Neutral Theory of Molecular Evolution, as it suggests that genetic changes happen independent of natural selection pressure, and instead occur because of genetic drift. Alternative terms for the Drifty Gene Hypothesis include the Neutral Theory hypothesis, the Random Drift hypothesis, and the Non-Adaptive hypothesis. These terms reflect the theory's central idea that some genetic changes occur randomly and are not affected by selection pressures, including the absence of selective advantages or disadvantages.