I'm a bit behind in my response, but the original question is why coconuts
would not develop natural poisons like other seeds. The answer is that
developing natural poisons is one of several evolutionary strategies that
seeds can adopt. Another is to have a very hard shell. The coconut with
its natural husk is very hard for most animals to open. So coconut is free
from poisons. In general, if you gathering food in the jungle, eat the nuts
with the hardest shells. They will be the safest. Ken