The Fugate family, also known as the "Blue People of Kentucky" have a condition known as methemoglobinemia which prevents hemoglobin from carrying oxygen and makes it difficult for unaffected hemoglobin to release oxygen to body tissues. This condition can be caused by exposure to drugs and chemicals, but can also be inherited, as with the Fugates. It causes their skin to be blue and their blood is brownish, due to a lack of oxygen, and is likely to be due to the absence of an enzyme. Martin Fugate came to Kentucky in 1820 and was reported to have been blue. He married Elizabeth Smith, with a normal complexion, although members of her family and other families in the region were blue.
Gene flow or migration is the transfer of alleles or genes from one population to another. Select the combination of facts that indicate the occurrence of gene flow in the Fugate family.
I. Four of the Fugate's seven children had blue complexions.
II. Travel in and out of this area was rare in the 1800's, but is more common now.
III. According to doctors, occurrence of the condition is rarely seen anymore.
IV. Methemoglobinemia at 10-20 percent of hemoglobin can cause blue skin without more serious symptoms.
Responses
A I. and IV.I. and IV.
B I. and III.I. and III.
C III. and IV.III. and IV.
D II. and III.
D. II. and III.
Travel in and out of the area being rare in the 1800's but more common now suggests that gene flow could have occurred over time, leading to a decrease in occurrence of the condition as mentioned by doctors.