As incorporated into the theory of quantum mechanics, this quantization of the energy of electrons and the resulting implications are regarded by physicists as part of the fundamental framework for understanding and describing nature.
An adult human has 206 bones. As compared to this a new born baby has about 270 bones. A baby is born with cartilage between some bones. This gives babies more flexible body structure, allows faster growth. As the baby grows, some groups of bones fuse together to form a single bone.
As of midyear 2002, the estimated Number of people ever born was 106.5 Billion. (The current world population at that time was estimated at about 6.2 Billion.) See related link (below) Answer Estimates are that between 69 billion and 110 billion people have populated the earth since about one million years ago.