PARASITISM ON MARS
Donald A. Windsor
Parasitism is a property of life on Earth, because most of our species are parasites (1). However, what about life on other worlds? We are on the verge of discovering life on Mars. Will Martian life have parasites?
If parasitism is a universal property of life, then it should occur in Martian life.
If Martian life does not have any parasites, then parasitism is unique to Earth. It would have to be decided on how many potential host species would have to be examined before it could reasonably concluded that no parasites occur.
Meanwhile, we should avoid contaminating the Martian biosphere, in case it has one.
1. Windsor, Donald A. Most of the species on Earth are parasites.
International Journal for Parasitology 1998 December; 28(12): 1939-1941.