Thread by @amymaxmen

*New* paper by virologists dissects claims & evidence on Covid's natural origins or a lab leak.

By @arambaut @edwardcholmes @stgoldst @angie_rasmussen et al

Some highlights 🧵 ⬇️ zenodo.org/record/5075888…

Most cases at the start of the outbreak link to markets selling animals. None link other localities, including the Wuhan Institute of Virology.

Genetic differences between the coronavirus from horseshoe bats (RaTG13) and SARS2 equates to decades of divergence. That means RaTG13 isn't the closest relative of SARS2 naturally or unnaturally.

These researchers *have* considered whether SARS-CoV-2 was engineered, and here's why they've found that this is highly unlikely. (No, it's not because they're liberals or blinding defending science.)

As for the claim that SARS-CoV-2 is "pre-adapted" for humans (a term that admittedly makes this former evolutionary biologist cringe)...

There's a lot more in this paper that spells out why virologists tend to feel that a zoonotic origin of COVID is still the more likely story.

These explanations back up (and go further than) my explainer a few weeks ago w/ @SmritiMallapaty nature.com/articles/d4158…