The mystery of peach/apricot/nectarine stones

[ecudc]

the reason why you get stone fruit is to do with the size of the seed. plants have evolved to not only cope with the fact that hungry creatures come along and try to eat their offspring but they actually encourage it by providing tasty 'fruit'. Animals eat the seeds and the most pass through the digestive system and out and germinate in a nice manure rich pile. Big seeds however can't be eaten whole so being eaten would destroy them. Instead they are coated in the stone so that an animal probably wonders away from the tree eating the fruit and drops it away from the original tree to germinate which worked well until squirrels and nutcrackers came along.