Thread by @gbrumfiel

NEW: A key scientist who signed the letter calling for investigation into the lab leak theory now says a natural origin "is the most likely scenario by a long shot."

It's based on his own analysis of where the first cases were found. (by @FoodieScience)
npr.org/sections/goats…

@FoodieScience Evolutionary biologist Michael Worobey, who's studied the origins of the 1918 flu and the beginning of the HIV/AIDS epidemic in America. He initially signed the letter because he hadn't seen anything that differentiated whether it came from the markets or the lab.

@FoodieScience But two things have swayed him that the market is (again) the most likely origin.

1. Initial cases clearly radiate out away from the markets, not the lab.

2. A newly published paper shows numerous live animals were being sold in the market...

nature.com/articles/s4159…

Of course none of this is definitive. As @Ayjchan points out in the article, there is a cluster of elderly people living near the market that may have amplified the signal in that area (though Worobey has his doubts).

And the Chinese govt has been far from transparent.

Meanwhile recent reporting from CNN suggests the U.S. intel community is shifting the other way, to believing a lab leak might be MORE credible:
cnn.com/2021/07/16/pol…

Though it sounds from this report that there isn't much new evidence either way...

It remains unlikely that the true origins of the virus can be known without a great deal more data.

And for all the powers of the intel agencies, I think most scientists think that it will require the cooperation of the Chinese government, which is not being helpful as of now.