原文：
The earliest split in the SARS-CoV-2 phylogeny defines two lineages - denoted A and B11 - that likely circulated contemporaneously (Fig. 1a). Lineage B, which became dominant globally, was observed in early cases linked to the Huanan market and environmental samples taken there, while lineage A contains a case with exposure to other markets (Fig. 1a,b) as well as with later cases in Wuhan and other parts of China10. This phylogenetic pattern is consistent with the emergence of SARS-CoV-2 involving one or more contacts with infected animals and/or traders, including multiple spill-over events, as potentially infected or susceptible animals were moved into or between Wuhan markets via shared supply chains and sold for human consumption5 . The potential emergence of SARS-CoV-2 across multiple markets again mirrors SARS-CoV in which high levels of infection, seroprevalence and genetic diversity in animals were documented at both the Dongmen market in Shenzhen4,12 and the Xinyuan market in Guangzhou13,14.
中文翻译：
SARS-CoV-2 系统发育中最早的分裂决定了两个谱系 – 被赋于 A 和 B（11），A和B可能同时流传下去（图 1a）。在全球占据主导地位的谱系B 支在与华南市场相关的早期案例和在那里采集的环境样本中观察到，而谱系 A 支包括一个暴露于其他市场的案例（图 1a，b）以及后来的武汉和中国其他地区的病例（10）。这种系统发育模式与SARS-CoV-2 的出现涉及与受感染动物和/或贸易商的一次或多次接触，包括多次溢出事件，因为可能感染或易感动物被转移通过共享供应链进入或在武汉市场之间进行销售，供人类消费（5）。这SARS-CoV-2 在多个市场的潜在出现再次类似于 SARS-CoV，其中动物的高感染水平、血清阳性率和遗传多样性被记录在深圳东门市场（4,12）和广州新园市场（13,14）。
