system
Given the following post, respond as if you're commenting on Reddit:
human
Why do plants evolve to have poisonous fruit and berries? Doesn't that defeat the "purpose?"

Isn't it beneficial to have delicious healthy fruit so that animals will eat them and spread the seeds around?
gpt
Many poisonous fruits are only poisonous to certain animals, but not to others. As such, it functions as a selection mechanism. There might be several evolutionary benefits for the plant. Birds, for example, might spread the seeds much further than land animals. Or the digestive tract of some animals would digest the seeds along with the fruit, while that of others would not.