It's more a matter of decreasing the error bars on the rate of substitution, to have extremely specific dates for the oldest infections in each clade and the ab

It's more a matter of decreasing the error bars on the rate of substitution, to have extremely specific dates for the oldest infections in each clade and the ability to run real-time backtesting to make sure your assumptions are solid. The rate of spread of Covid was a curse but was important to this type of work -- when we were looking at contact tracing and trying to assess the rate of substitution on mutations, it was useful to know that e.g. on Jan 1st there was no Covid in NYC and on Feb 1st there was.