Here is an idea to consider concerning mutations:
Maintaining temperature may play a role in decreasing mutations.
This was sparked by a quote from the book title “Introducing Genetics,” by Jones and Van Loon, …even a slight increase in temperature doubled the rate (of lethal mutations in fruit flies).”
Days later it dawned on me that the reverse was probably true. Thermal regulation in birds and mammals may decrease mutations. Perhaps that is even one reason for the thermal regulation. It would seem to me that if temperature regulation would reduce mutations; that would be a very important way to keep the genome as is. That would be a very big plus for any species.