Final answer:
Most people exhibit the greatest sensitivity to the bitter taste, which acts as a natural protection against toxins. The umami taste, associated with savory foods rich in protein, was identified later and has nutritional significance. Genetic factors contribute to individual differences in taste sensitivity, affecting dietary habits and health.
Step-by-step explanation:
Most people have the greatest sensitivity to the basic taste of bitterness. The human tongue has evolved to detect this taste as a natural warning system against the consumption of potentially toxic substances, which often have a bitter taste. The five primary tastes that humans can discern are sweet, sour, salty, umami (or savory), and bitter. Of these, the umami taste was recognized relatively recently when Japanese scientist Kikunae Ikeda identified it while working with seaweed broth in 1908.
Umami corresponds to the flavor of L-glutamate, an amino acid found abundantly in protein-rich foods. This is relevant in human evolution as having sensitivity to umami helped our ancestors seek out nutrient-rich foods.
Overall, variations in taste sensitivity among individuals can be linked to genetic factors, and these perceptual differences influence dietary choices and nutritional health. The relationship between taste perception and metabolism, as well as the impact on body weight, are areas of ongoing research in the field of gustatory science.