They destroy things that cost lots of money to repair, or they put people in hospitals, and that would cost a lot of money too.
Human height is one of the traits that belong to traits that cannot easily be placed in discrete phenotypic classes (there is not only tall and short people, there is continuous variation of height between them). Such traits are usually controlled by more than one gene (polygenic traits).
On the other hand, a Mendelian trait is controlled by a single locus.
The overall biodiversity in the Gulf of Mexico has gone down since the Deepwater Horizon spill. I hope this helps.
