還是要謝謝這個機會!
先勞pifu01大駕前往GISAID網站 https://www.gisaid.org/epiflu-applications/next-hcov-19-app/
暫別忙着講解,將主頁往下移,請認真閱讀主頁病毒流行圖的構建注釋:
This phylogeny shows evolutionary relationships of hCoV-19 (or SARS-CoV-2) viruses from the ongoing novel coronavirus COVID-19 pandemic. This phylogeny shows an initial emergence in Wuhan, China, in Nov-Dec 2019 followed by sustained human-to-human transmission leading to sampled infections. Although the genetic relationships among sampled viruses are quite clear, there is considerable uncertainty surrounding estimates of transmission dates and in reconstruction of geographic spread. Please be aware that specific inferred transmission patterns are only a hypothesis.
Site numbering and genome structure uses Wuhan-Hu-1/2019 as reference. The phylogeny is rooted relative to early samples from Wuhan. Temporal resolution assumes a nucleotide substitution rate of 8 × 10^-4 subs per site per year. Full details on bioinformatic processing can be found here.
以武漢首先檢測、確定並公開報告的新冠病毒感染病例為起始點構建的流行圖在直觀的表面形式上當然只能是“溯源”到武漢了。
但這並不如你所謂一目了然,說武漢毒株是其它後續檢測並報告的毒株的共同祖先!!!
很簡單,舉個不一定恰當的例子。考古學家2019年在武漢發掘出的晚清瓷器不一定是2020年在美國發掘出的前清瓷器的祖輩。
究竟哪個是前清的,哪個是晚清的,得有可靠的科學證據來判斷。你是行內人,早就做過phylogenetic tree,應該知道病毒的核酸序列是可靠的科學依據。
那麼好,現在請你往下看GISAID的病毒核酸序列進化樹。
Phylogenetic context of nCoV in SARS-related betacoronaviruses can be seen HERE.
點擊HERE進入病毒的系統發育分析(即進化樹);
不妨先與你所謂一目了然的網站首頁的圖做一比較;
再仔細看SARS-CoV-2(即新冠病毒)分支的進化簇;
移動鼠標到任一進化分支上時,圖上會彈出相關的數據注釋窗;
點擊任一進化分支可以放大該分支的細節。每一進化分支都註明了病毒核酸順序來源。
然後請填空
病毒進化位置:——————————
若有錯誤之處,請不吝指教。