3 ms·

But we'd have to be missing a huge number of related strains to make the phylogeny look like that. The important thing isn't that we found a new strain now, it'

• nostrademons 5y ago
  Or the population that it evolved in is isolated, so it never escaped back into the developed world until now. Somewhat unlikely given how interconnected the world is now, but it is Africa after all.
• whimsicalism 5y ago
  Well yeah, many of the places with the worst testing coverage are probably close to each other geographically.
• timr 5y ago
  > But we'd have to be missing a huge number of related strains to make the phylogeny look like that Define "huge". There are about ~30 mutations on the spike protein from the closest known relative, and there's a fairly strong selective pressure against the wild type (both from vaccine and natural infection). I think it's quite probable that we missed a few months of evolution of a strain circulating in a single-digit percentage of people. This is particularly true when you consider that this strain has S-gene dropout (Delta does not), and was probably dismissed as Beta and never targeted for sequencing by most labs. That's why I meant by my original comment that we're biased about what we look at.