Question

Bodmer and McKie (1995) review several cases, similar to achromatopsia in the Pingelapese, in which genetic diseases occur at unusually high frequency in populations that are, or once were, relatively isolated. An enzyme deficiency called hereditary tyrosinemia, for example, occurs at an unusually high rate in the Chicoutimi region north of Quebec City in Canada. A condition called por- phyria is unusually common in South Africans of Dutch descent. Why are genetic diseases so com- mon in isolated populations? What else do these populations all have in common?

Answer 1

Genetic diseases are common in isolated populations due to genetic drift and strict endogamy. Isolated populations have limited gene flow and may have unique environmental factors that increase the prevalence of genetic diseases.

Step-by-step explanation:

Genetic diseases are common in isolated populations due to several factors. One factor is genetic drift, where the frequency of rare alleles can increase over time in small populations. Strict endogamy, or the practice of marrying within a specific cultural group, can also contribute to the rise in frequency of certain genetic diseases. Additionally, some isolated populations may have unique environmental factors that increase the prevalence of certain genetic diseases. These populations all have in common the isolation and limited gene flow from surrounding populations.