Final answer:
Heritability is important for natural selection as it determines the genetic variation that can be acted upon. Measuring heritability can be difficult due to the need to distinguish between genetic and environmental factors. Twin studies, adoption studies, and breeding experiments can help estimate heritability.
Step-by-step explanation:
Heritability is the fraction of phenotype variation that can be attributed to genetic differences among individuals in a population. It is an important concept for natural selection because without genetic variation, there would be no traits for natural selection to act upon. When heritability is high, traits that confer a fitness advantage can be passed on to future generations, leading to evolutionary change through natural selection.
Measuring heritability can be challenging because it requires distinguishing between genetic and environmental factors that contribute to phenotypic variation. Twin studies, adoption studies, and breeding experiments are some methods used to estimate heritability. These studies compare the similarity of traits in individuals with known genetic relationships or controlled breeding conditions.