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Why Covid-19’s Origin Story Is Still a Mystery
Inside the puzzle to reconstruct the history of SARS-CoV-2 and how it spilled over into humans
As the Covid-19 pandemic disrupts the lives of billions around the world, two questions continue to linger: Where did the virus come from, and how did it find its way into humans?
Scientists have been hunting for those answers since the first cluster of unusual pneumonia cases emerged in China in December 2019. Investigating the origin of the novel coronavirus is a daunting task that can be compared with assembling a difficult jigsaw puzzle with most of its pieces missing. But mapping out the virus’s spread is of crucial importance to prevent new epidemics. Discovering where the virus came from could teach scientists and leaders how to avoid the situations where viruses are most likely to be introduced into humans.
The initial puzzle pieces of the Covid-19 pandemic were put together when whole genome sequencing of the virus showed that it shared 79.5% of its RNA with SARS-CoV, the coronavirus that had been responsible for the 2003 SARS outbreak, and was even more similar (96.2% identical) to another coronavirus called RaTG13, which had been previously found in a bat. This strongly suggested that the newly identified SARS-CoV-2 also came from bats.
