Evolutionary threat: Chinese mountain birds lost nearly half genetic diversity in 50 years

Genetic diversity is nature’s insurance policy – an evolutionary safety net that provides the building blocks for natural selection. While members of the same species share a mostly identical genome, a sliver of unique genetic variants determines their individual traits. When this diversity erodes, and a population becomes more uniform, it could leave them vulnerable to the same threats and unable to adapt when new ones emerge. In China, scientists have found that common songbird species were...