Mutation can cause DNA to change
After reading the above information, one reason different members of crow populations have a different rate of survival is there is always a chance that that some other variation will also effect some of the crows ability to survive. Another reason is that the vision, muscle strength and size can influence survival.
Answer:
To increase the preservation of an element, it should go through all the stages as it should, which could promptly take it to its ruin phase.
This must be analyzed from the theoretical point of view, it will be worthwhile for the human to go so fast through the phases of his life, shortening the chances of subsistence or we must burn all stages in due time.