Question 6: evolution, through natural selection, chooses traits that increase the reproductive fitness of the organism. in other words, if some members of a population have trait x, and if trait x means that they produce more offspring that survive to maturity and reproduce, then trait x will become more common in the population. given this definition of evolution, consider each of the interaction categories (competition, commensalism, predation, parasitism, herbivory, or mutualism). predict how each of the species in the interaction might evolve. for example, a parasite might evolve to become less virulent so that it doesn’t kill so many of its hosts. did you predict that in each interaction there would be an evolutionary pressure to reduce negative effects or increase positive effects? th ose predictions make sense, but why, after 3.5 billion years of evolution, do we still have interactions with negative effects?