Final answer:
The founder effect describes how a new population started by few individuals can lead to differences in genetic makeup from the original population. This effect is exemplified by the Amish population's high incidence of Ellis-van Creveld syndrome and the Afrikaner population's prevalence of Huntington's disease and Fanconi anemia.
Step-by-step explanation:
Founder Effect Explained
The founder effect is a phenomenon in biology where a new population is established by a very small number of individuals from a larger population. This small group may not have the same allele frequencies as the original population, leading to a new population with a different genetic makeup.
Classic Example: The Amish Community
One classic example of the founder effect is observed in the Amish community, which was founded by approximately 200 German immigrants. This group brought with them certain genetic mutations, such as those causing Ellis-van Creveld syndrome, leading to a high occurrence of this condition among present-day Amish populations because of the limited initial genetic variation.
Importance of Genetic Diversity
Another scenario illustrating the founder effect is seen with the Afrikaner population in South Africa. This population shows a higher prevalence of Huntington's disease and Fanconi anemia, presumably due to a higher frequency of these mutations in the founding members. Consequently, the current population exhibits these genetic disorders at unusual levels.