I was just wondering if there is such things as intelligent plants. I saw a tree with spikes on it when I was living in Spain
http://www.worldofstock.com/closeups/NTR1592.php and my mum told me that it was to stop animals climbing up it to get its fruit. I thought how does a tree know that an animal is climbing up it to get its fruit? It has no eyes to see the animal and no brain to process the fact that an animal is climbing up on it, let alone that an animal is trying to steal its fruit. On top of that, how does it know to grow spikes and how does it know that these spikes will deter animals?
This occurs with other trees and plants in the Plantae Kingdom, such as cacti. How do they know, how did they learn?
I assumed that it was evolution, natural selection, but why would a tree grow spikes in the first place? They do not have any use to the tree?
Any thoughts?