Heterozygote advantage occurs when heterozygotes have a higher fitness than do both homozygotes. In frequency-dependant selection, the fitness of a phenotype declines it it becomes too common in the population.
Explanation;
The heterozygotes have both alleles, which is needed for genetic variation. Heterozygotes are essential for there to be genetic variation in a population. In other words it is when When a single copy of a disease allele doesn't result in a disease but instead is good for the person or organism that carries it, we say that allele has a heterozygote advantage. For example a sickle cell trait, which protects against malaria in heterozygotes, but causes a deadly disease in homozygotes.
-Frequency-dependent selection occurs when the fitness of a genotype depends on its frequency. It is possible for the fitness of a genotype to increase (positively frequency-dependent) or decrease (negatively frequency-dependent) as the genotype frequency in the population increases.
Thermal energy causes matter to change state beacuse evrything has heat which is thermal energy hore heat is more thermal energy. Ex.Ice changes into water Ex.Water changes into water vapor
