jar diamond make a point in the first episode that other people of the world do not have animal to domesticate but european do and and that account for why we be able to make steel and invent complex machine . it be obvious that the person who write this comment hasn not understood the reasoning behind this documentary or the original book . please do not ruin this great piece by your simple mindedness . the reason be far more complex than the single thing you mention . please read the book a be it a great source of information . i enjoy it a lot . this book be even a taught a a text book at some university .