Final answer:
The statement is false; traits that are helpful in one environment can become harmful if conditions change. Adaptations are key to an organism's survival and reproduction, but no trait is universally beneficial as environmental pressures can modify their effectiveness.
Step-by-step explanation:
The statement that traits of organisms that help them in some way will never be harmful is false. Although traits are generally adaptations that enhance an organism's fitness, they can sometimes become detrimental under certain conditions.
Most traits are inherited and can vary among offspring, leading to differences in their survival and reproduction. These traits can provide advantages under specific environmental conditions. However, environments can change, and a trait that's beneficial in one context may become a disadvantage in another. This is evident in the case of finches, where the benefits of bill size reversed with changes in climate. It's important to understand that natural selection acts on the existing genetic variation within a population, but it cannot engineer 'perfect' organisms free of all harmful traits.
Moreover, the handicap principle and the good genes hypothesis suggest that a trait can signal the quality of a male to a female, aiding in mate selection. As environments and conditions fluctuate, so does the usefulness of certain traits, and traits that may seem indispensable at one point may turn out to be harmful if circumstances change.