How Does Diamond Explain The Fact That American Apples And Grapes Were Not Domesticated Until The Arrival Of The Europeans?

How Does Diamond Explain The Fact That American Apples And Grapes Were Not Domesticated Until The Arrival Of The Europeans? How does Diamond explain the fact that domesticable American apple and grapes were not domesticated until the early arrival of Europeans? … It shows us a timeline of when different domestication so were made. How