I read Guns, Germs, and Steel a long time ago, but I'm pretty sure it focuses quite heavily on disease wiping 90+% of the native population and how decisive tha

I read Guns, Germs, and Steel a long time ago, but I'm pretty sure it focuses quite heavily on disease wiping 90+% of the native population and how decisive that was. I remember this because I was shocked when reading it that the percentage might be that high. One clue that the book is concerned with disease is the second word in the title.