Why do some tree fruits grow out of trunks?

Trunk-borne fruits are unusual, but include the well-known papaya, the commercially-marketed durian, and the largest of tree fruit, the jackfruit. The location of flowers and fruit on the branches or trunk is likely a response to the need for high levels of water transport, and fruit weight that could not be borne by leafy smaller stems. It is also possible that variants with the fruit in this location benefit from increased transport of their seeds, as fruits are accessible to heavier climbing animals, rather than falling from the trees when ripe.