Overview
- Published in Science on Oct. 23, the study estimates the human-biting molestus lineage diverged from bird-biting pipiens roughly 1,300–12,500 years ago, most likely in Mediterranean or Near Eastern agricultural settings.
- Researchers analyzed 357 contemporary genomes from 77 locations plus 22 museum specimens, supplementing with additional datasets to assess about 800 mosquitoes gathered through collaborations with roughly 150 organizations.
- Traits suited to subterranean life—mammal biting, mating in confined spaces, year-round activity, and laying eggs without a blood meal—were already present in ancient populations, enabling later use of sewers and subways.
- Hybridization between molestus and pipiens appears less common than previously believed yet occurs in big cities, supporting a working hypothesis that urban gene flow could elevate West Nile virus spillover risk and warrants further study.
- The team could not collect live samples from the London Underground, and the authors note uncertainty in divergence dating and call for expanded behavioral and urban–rural sampling to refine public-health assessments.