What is the distribution/probability density function (PDF) of impacts on fitness of new mutations?
I very welcome any partial answer that does not give the whole PDF but just some information about the expected value or the variance of this distribution. Information of the kind: "If we consider only beneficial mutations, then the PDF is $P(X=x) = f(x)$" are also welcome.
When I say mutations, one might have want to reduce the concept of mutations only to indels and point mutations.
Of course the answer will depend on the species under consideration and from population to population but I welcome any answer that could give some insights. Eventually, some information according to what is generally assumed to be the PDF of effects on fitness of new mutations might be useful.
Here is a related question
Here is an article that assumes an exponential distribution of effects on fitness of beneficial mutations.