There's an interesting discussion in Gun, Germs, and Steel where Jared Diamond claims that wild apples were inedible (IIRC due to cyanide in the seeds) and coul

There's an interesting discussion in Gun, Germs, and Steel where Jared Diamond claims that wild apples were inedible (IIRC due to cyanide in the seeds) and could only be domesticated after the invention of grafting technology.