gen-briefly-explain-genetic-variation-in-a-population-and-one-co-b21a

Briefly explain genetic variation in a population and one common misconception about it.

# Genetic Variation in a Population **What it is:** Genetic variation refers to the differences in DNA sequences among individuals within a population. This variation arises through mutations, sexual reproduction (recombination), and gene flow. It's the raw material for evolution, allowing populations to adapt to changing environments through natural selection. ## Common Misconception **"Evolution creates new traits as needed"** Many people believe that when an environment changes, organisms somehow develop the necessary adaptations in response. In reality, genetic variation must *already exist* in the population (or arise randomly through mutation) before natural selection can act on it. For example, some bacteria weren't "trying" to become antibiotic-resistant when exposed to antibiotics—resistant individuals already existed due to random mutations, and they simply survived and reproduced more successfully than non-resistant ones. Evolution works by selecting from existing variation, not by generating custom solutions on demand.