To know where it rightfully belongs to. Variation of certain traits is caused by multiple factors of an individual of the same kind. Depending on their physical appearance, their environment and nature of survival.
Hope this might help.
When the muscle or the skeletal muscle cells undergo anaerobic respiration, they become painful and fatingued, it is now known to be caused by build up of lactate. The skeletal muscle will be painful and fatigued and the caused of it will be because by build up of lactate.
