14. directions: select each correct answer. more than one answer may be correct.
new species of organisms may emerge if

an individual organism makes sudden dietary changes.
a mutation results in a fatal condition.
two diverse species naturally interbreed.
selective pressures favor new traits in a given environment.

According to the article, what valid claim came from the national research council? there is no association between fluoride exposure and increased cancer risk in humans. there is a possible link between fluoride exposure and increased cancer risk in humans. there is a definite link between fluoride exposure and increased cancer risk in humans.