Genetic diversity is the raw material for evolution, and it allows species to adapt to changing environmental conditions. But can fisheries cause species to lose genetic diversity? In our meta-analysis just out this week in Molecular Ecology (OnlineEarly), we find strong evidence that the answer is yes. Previously, studies on individual populations have had somewhat ambiguous results: some studies found an effect, others did not. Our finding provides more evidence that the evolutionary impacts of overharvest are important for fisheries management, and may explain why some heavily overfished populations (e.g., Newfoundland cod) have had such a hard time recovering.