Mutations and genetic variation drive evolution, but changes occur incrementally over generations. Slight modifications in an organism’s traits—like morphology, physiology, or behavior—can improve survival and reproduction. These changes spread gradually across a population, accumulating over time. Eventually, small, advantageous differences can lead to entirely new species.
Arctic-dwelling brown bears evolved into polar bears not through sudden changes but through slight genetic variations. Traits like lighter fur and better fat metabolism increased survival in cold environments. These subtle adaptations became widespread over generations, culminating in a species uniquely suited to the Arctic.
DNA is the blueprint for an organism’s traits, inherited from both parents. This inheritance, combined with random mutations, introduces variability into populations. While many mutations have no effect, some offer small advantages. Over time, these advantages are selected and refined, demonstrating the power of gradual change to shape life on Earth.
