Final answer:
The thrifty genotype is a hypothesis suggesting that certain genes allow individuals to efficiently store fat, aiding survival during famines and leading to a higher likelihood of these genes being passed on to future generations.
Step-by-step explanation:
The thrifty genotype refers to the hypothesis that certain genes ("thrifty genes") evolved in human populations to optimize energy storage. These genes allow individuals to consume fewer calories and store the excess as body fat, which could be advantageous during periods of famine. According to this idea, individuals who carry these genes are more efficient in storing fat and thus have a higher chance of surviving and passing the thrifty genotype to their descendants.
In a text discussing genotypes and phenotypes, the thrifty genotype can be seen as one of the various genetic makeup scenarios predicted by Mendelian genetics. While genotype refers to the specific allelic composition of an organism, phenotype refers to the visible or expressed traits resulting from the interaction of these alleles. Though not explicitly addressed in lectures, the concept of the thrifty genotype falls under the broader scope of genetics, where certain genotypes can result in advantageous phenotypes under specific environmental conditions.