O-19 - Both early lineages A and B recovered from environmental swabs in the market's west wing
Recovery of both lineages from the market environment matters because a market-origin scenario for both lineages predicts both should be detectable there; the four genomes were all from the west-wing wildlife area.
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Why this is evidence
A single external human seed (H-15) would most likely bring one lineage; both independent lineages recovered from the market’s wildlife-wing environment favor the market as their common emergence locus (H-14) over H-15.