Mechanism of Male Pattern Balding?

Can you explain more in detail the actual mechanism of MPB? I know that some hair follicles are sensitive to DHT and somehow the DHT causes miniaturization, but how does this actually work?  Also, any wisdom on why some hairs develop later in life even where there were no (or not visible?) follicles. Like pubic hair and hairs on the chest and back as men age?

I am not going to write a book to answer your question but here is a quick summary:  People who have the genes for hair loss, when exposed to DHT (normal for men to have this) trigger the process called Apoptosis (the progression of cell death) for hair follicles carrying the genes. DHT works directly on the growth center in the impacted hairs. Drugs like finasteride or dutasteride block this process so it slows down the effects of the DHT and the balding that occurs.