Drs. Sanford and Carter respond to PS Scientists

[John_Harshman]

@dsterncardinale

And since mutations are approximately random, we should expect variance.

Not, I think, for nearly neutral mutations.

@dsterncardinale

Mutations accumulate without being selected against, and then at some point the population goes extinct. That means at some point you have to go from “no fitness cost” to “high fitness cost”. There’s an inflection point there, a fitness cliff.

Just not true. It’s a completely gradual accumulation of reduced absolute fitness, and again there’s a cost to absolute fitness but no significant differential in relative fitness. I don’t think you understand Sanford’s model.