Final answer:
The best evidence that environmental changes can affect traits in later generations is when some individuals, due to genetic variability, are better suited to new conditions and pass their advantageous traits to future generations.
Step-by-step explanation:
The statement that provides the best evidence that an environmental change can affect traits in later generations of an organism's population is: Similarly, when a significant and lasting change occurs in the environment of a population, some individuals, because of the genetic variability in the population, may be better suited than others to the new conditions. These individuals are more likely to survive and successfully reproduce, passing on their genes to subsequent generations. This is a reflection of natural selection, where individuals most adapted to their environment are more likely to survive and pass their traits to the next generation. Additionally, genetic changes that affect phenotypes and are beneficial within the new environment will increase in frequency within the population, according to the principle of selection outlined in 3.C.1 Genetic changes that affect phenotypes are subject to selection.