A covarion or site-specific-rate-variation model of sequence evolution describes a process in which the substitution rate of each character (nucleotide, codon, amino acid) can speed up or slow down over time, as might be caused by changing functional constraints. Though the model was formulated a decade ago, only in the last few years was it shown that the topology of the evolutionary tree is identifiable for this model. We now establish identifiability of the numerical parameters, such as edge lengths and substitution rates. Necessary technical assumptions are that the number of rate classes be less than the number of character states, the tree relates at least 7 taxa, and numerical parameters are `generic'.
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