Drift theory

Drift theory is a concept in evolutionary biology that suggests species evolve gradually over time due to small, random genetic changes rather than through large, sudden shifts. This theory emphasizes the role of genetic drift—random fluctuations in traits within a population—that can lead to variations becoming more common or disappearing. Such changes occur independently of natural selection, meaning they aren't always beneficial or adaptive. Drift theory helps explain diversity in species and how populations adapt to their environments over long periods, highlighting the random nature of evolutionary processes.