Final answer:
Male marine iguanas with longer body lengths are likely to have higher reproductive success on Genovesa and Santa Fe, as traits giving a survival or reproductive advantage tend to be favored by natural selection.
Step-by-step explanation:
The relationship between marine iguana body length and reproductive success for male iguanas on Genovesa and Santa Fe has been a subject of interest similar to Darwin’s observations of the Galápagos tortoises. Darwin noted that longer-necked tortoises were more likely to survive and reproduce in environments where food was harder to reach. We can infer from this concept of natural selection that in environments where certain physical traits provide a survival or reproductive advantage, those traits would become more common over generations. For male marine iguanas, body size often correlates with dominance and access to mates, hence longer body length may offer an advantage for reproductive success. Therefore, it is reasonable to assume, unless contrary evidence is provided specifically for these populations, that c) The longer the body length, the higher the reproductive success among male marine iguanas on Genovesa and Santa Fe.