What does the handicap principle in sexual selection propose?

What does the handicap principle in sexual selection propose?

• A. Costly traits reliably indicate good genetic quality because only high-quality individuals can bear the cost.
• B. Traits that are cheap signals can indicate quality even in low-status individuals.
• C. Territorial defense is the primary driver of such signals.
• D. Pheromones are the main indicators of genetic quality in mate choice.

Answer: (A)

Honest signaling through costly traits is the idea here. The handicap principle says that traits that are expensive to produce or maintain can reliably indicate an individual's genetic quality because only those in good condition can bear the cost. In other words, the cost itself ensures honesty: if a low-quality individual tried to fake the trait, the burden would reduce its survival or future reproduction, so the signal wouldn’t be advantageous. This is why such exaggerated traits can persist as reliable cues to potential mates about genetic fitness. For example, an elaborate tail may help attract mates but also imposes risks and energy costs; only the fittest males can afford to bear that handicap, so the trait signals true quality. The other ideas miss this core point: cheap signals wouldn’t reliably indicate quality, and territorial defense or pheromones aren’t the central mechanism the handicap principle describes.

Honest signaling through costly traits is the idea here. The handicap principle says that traits that are expensive to produce or maintain can reliably indicate an individual's genetic quality because only those in good condition can bear the cost. In other words, the cost itself ensures honesty: if a low-quality individual tried to fake the trait, the burden would reduce its survival or future reproduction, so the signal wouldn’t be advantageous. This is why such exaggerated traits can persist as reliable cues to potential mates about genetic fitness. For example, an elaborate tail may help attract mates but also imposes risks and energy costs; only the fittest males can afford to bear that handicap, so the trait signals true quality. The other ideas miss this core point: cheap signals wouldn’t reliably indicate quality, and territorial defense or pheromones aren’t the central mechanism the handicap principle describes.