Question

Researchers have noted that African Americans have higher rates of sickle cell anemia than do white Americans. They have also noted that people in some regions of Africa have high levels of the sickle cell trait, which is believed to help protect people from malaria. Therefore, the majority of African Americans must be descended from people from the regions of Africa that have high levels of sickle cell trait. Which of the following, if true, most weakens the argument?

• A. The areas of Africa with high levels of sickle cell trait were heavily involved in the slave trade.
• B. Slaves in the American South were exposed to malaria at high levels.
• C. People with sickle cell trait are less likely to die from malaria than those without this trait.
• D. The areas of Africa with high levels of sickle cell trait were not areas of heavy slave traffic.
• E. It is impossible to tell from DNA analysis what someone's ancestry is.

Hint:

Always consider alternative explanations that could weaken causal or ancestral claims.

Answer 1

The Correct Option is A

Step 1: Understanding the argument.
The argument claims that higher rates of sickle cell anemia in African Americans are due to their descent from African regions with high levels of the sickle cell trait. This is based on the assumption that these regions were the main source of African American ancestry.

Step 2: Analyzing the options.
- (A) The areas of Africa with high levels of sickle cell trait were heavily involved in the slave trade: This weakens the argument because it suggests that people from other regions of Africa, not just those with high levels of sickle cell trait, may have been brought to the U.S. through the slave trade, diluting the connection.
- (B) Slaves in the American South were exposed to malaria at high levels: This does not weaken the argument because it does not address the ancestral origin of African Americans.
- (C) People with sickle cell trait are less likely to die from malaria than those without this trait: This supports the idea that sickle cell trait is protective, but it doesn't weaken the argument about ancestry.
- (D) The areas of Africa with high levels of sickle cell trait were not areas of heavy slave traffic: This would weaken the argument but doesn't completely dismantle it.
- (E) It is impossible to tell from DNA analysis what someone's ancestry is: This is not relevant to the argument as it does not directly address the evidence for ancestry from specific regions.

Step 3: Conclusion.
Option (A) weakens the argument most by suggesting that the origin of African American ancestry is more complex than the regions with high sickle cell trait levels.