Parameters affecting adaptation scenarios

. Parameters affecting adaptation scenarios

If we think of adaptation as an adjustment and environmental changes, we have seen that adaptive mutation can occur as a result of two scenarios - different from the population there was no prior adaptive change, or from a new mutation that appeared after the change.

A.. What situation has had more different from the existing adaptation - when an organism living environment stable or when there are frequent environmental changes?

On. How does population size effects  on the calculations shown above ,until the total time for fixation of the adaptation , from new diversity?
What is the difference with our scenario compare with neutral fixation?
(Note that the intention here is not only for the time to take the same allele fixated on the population, but the total time from the moment given that there is no allele from until he fixated in the  population as a whole)