Question

the graph shows data on the clutch sizes of american robins. clutch size is the number of eggs laid in a nest. which conclusion is best supported by evidence in the graph? a there is no variation in the clutch size trait, so the trait cannot be influenced by natural selection. b variation exists in the clutch size trait, and larger clutch sizes lead to more reproductive success. c there is no variation in the clutch size trait, because it is most advantageous to produce three to four eggs. d variation exists in the clutch size trait, and it is a reproductive advantage to raise a clutch of three to four offspring.

Explanation:

The bar - graph shows different clutch sizes (number of eggs laid) and their corresponding number of observations. Since there are multiple clutch sizes observed (1 - 7 eggs), variation exists in the clutch - size trait. Larger clutch sizes can potentially lead to more reproductive success as more offspring have the chance to survive.

Answer:

d. Variation exists in the clutch size trait, and it is a reproductive advantage to raise a clutch of three to four offspring.