Apopulation of rabbits includes rabbits with pink noses spots and rabbits with black noses. a forest fire kills half the rabbits with pink noses. this is an example of genetic drift mutation gene flow natural selection

well when looking at this if you think about it   negativley and positivley   react with each other and when the first layer gets full they add layers it starts with 2 on the first layer and it constantly goes on until the official number is there

take a break move to stretching and slowly work back into physically exercising if the problem continues go to a doctor or physical therapist