Overview
- UC San Diego researchers analyzed genomes from influenza A, Ebola, Marburg, mpox, SARS-CoV and SARS-CoV-2 and found pre-outbreak selection resembled routine circulation in animal reservoirs.
- The authors report no evolutionary evidence that SARS-CoV-2 was shaped by laboratory selection or by prolonged evolution in an intermediate host before its emergence.
- The team applied a genome-wide phylogenetic framework that tracks changes in selection intensity, confirming its accuracy with viruses adapted in cell culture or laboratory animals that show distinct signatures.
- The 1977 reemergence of H1N1 influenza displayed minimal divergence from 1950s strains and lab-like selection patterns, which the authors say supports a long-suspected laboratory link.
- The study proposes this framework as a benchmark for outbreak forensics, surveillance and preparedness, and notes funding from NIH-NIAID and NSF along with author disclosure of consulting and expert testimony.