What is an appropriate definition of the evolutionary rate?

Last updated: 8/10/2022

What is an appropriate definition of the evolutionary rate? The rate at which novel mutations arise (per site or per genome) when genomes replicate. The estimated rate at which novel genes arise. The estimated rate at which nucleotide changes (per site or per genome) are observed within a population sampled over a particular timescale. The estimated rate at which pathogens escape immune response.