Final answer:
Breeding the hottest chili peppers will likely result in a population with higher levels of capsaicin, leading to a stronger perception of heat. Capsaicin activates sodium channels in warm receptors, causing the sensation of spiciness or pain.
Step-by-step explanation:
If you breed only the hottest chili peppers over many generations, the characteristic of the resulting population will be peppers that contain a higher concentration of capsaicin, which is the molecule responsible for the 'heat' in chili peppers. Capsaicin interacts with sensory receptors, specifically the ones that detect warmth, hence causing the perception of heat or pain when consumed. Some individuals can tolerate this sensation better because they may have fewer receptors or a reduced sensitivity to capsaicin.
Over generations, selective breeding for the hottest chili peppers will likely produce a population with consistently high levels of capsaicin, making the peppers significantly hotter as a direct response to this selection pressure. The heat of these peppers is not due to capsaicin being corrosive or containing heat, but rather because it triggers certain channels in the sensory neurons, leading to the sensation of pain or spiciness that we associate with hot peppers.
Explanation of Perception of Heat
People experience the sensation of heat from peppers differently due to the number of warm receptors they have and their individual threshold for pain. Capsaicin doesn't cause tissue damage; it simply opens the same sodium channels as warm receptors. Excess stimulation of these receptors manifests as a burning sensation, explaining why some people perceive peppers as being painful or hot, while others find them tolerable or even enjoyable.