Question

% babies born at different weights
which statement is a valid claim that could be made using the data in the graph?

• directional selection is occurring because the graph favors an extreme.
• stabilizing selection is occurring because the average is favored.
• disruptive selection is occurring because the two extremes are favored.
• biodiversity variation is occurring because there is an increase in trait variation.

Explanation:

1. Analyze each option:

• Directional selection: Favors one extreme, but the graph peaks at the average (around 7 - 8.5 lb), not an extreme. Eliminate this.
• Stabilizing selection: Favors the average (intermediate phenotype), reducing extreme variations. The graph's peak at the middle weight range (average birth weight) matches this.
• Disruptive selection: Favors two extremes, but the graph has a single peak at the average, not two peaks at extremes. Eliminate this.
• Biodiversity variation: The graph shows a normal distribution around average weight, not an increase in trait variation (extremes are low). Eliminate this.

Answer:

B. Stabilizing selection is occurring because the average is favored.