An interesting point came up this past summer when discussing allergies in cities. The trees that are planted in cities tend to be male since female trees will

An interesting point came up this past summer when discussing allergies in cities. The trees that are planted in cities tend to be male since female trees will bear fruit and are messy. I wonder if the lack of diversity (yes even in trees!) is causing problems. If there were a mix of male and female would trees be able to evolve or at least grow more offspring.