All of the following statements support the hypothesis that humans cannot be classified into biological races except:
a. There is more genetic diversity within a racial group than average differences between racial groups.
b. Alleles that are common in one population in a racial group may be uncommon in other populations of the same race.
c. Geneticists can use particular SNP alleles to identify the ancestral group(s) of any individual human.
d. There are no alleles found in all members of a given racial group.
e. There is genetic evidence of mixing among human populations occurring thousands of years ago until the present.

Verified step by step guidance

1. Step 1: Understand the question. The problem asks which statement does NOT support the hypothesis that humans cannot be classified into biological races. This means we are looking for the exception among the given statements.
2. Step 2: Review the hypothesis. The hypothesis states that humans cannot be classified into biological races. This is based on the idea that genetic variation does not align neatly with traditional racial categories.
3. Step 3: Analyze each statement: - (a) This supports the hypothesis because it highlights that genetic diversity within a racial group is greater than differences between groups. - (b) This supports the hypothesis because it shows that alleles vary even within populations of the same race. - (c) This does NOT support the hypothesis because it suggests that specific genetic markers (SNP alleles) can identify ancestral groups, implying some genetic distinction. - (d) This supports the hypothesis because it states that no allele is exclusive to a racial group. - (e) This supports the hypothesis because it shows evidence of genetic mixing, which blurs racial boundaries.
4. Step 4: Identify the exception. Based on the analysis, statement (c) is the exception because it implies that genetic markers can be used to distinguish ancestral groups, which could be interpreted as supporting the concept of biological races.
5. Step 5: Conclude that the correct answer is (c), as it does not align with the hypothesis that humans cannot be classified into biological races.

Key Concepts

Genetic Diversity

Genetic diversity refers to the total number of genetic characteristics in the genetic makeup of a species. In the context of human populations, it highlights that there is often more genetic variation within so-called racial groups than between them, suggesting that traditional racial classifications do not accurately reflect biological differences.

Single Nucleotide Polymorphisms (SNPs)

Single nucleotide polymorphisms (SNPs) are variations at a single position in a DNA sequence among individuals. Geneticists use SNPs to trace ancestry and population structure, but the presence of specific SNPs does not necessarily correlate with racial classifications, indicating that genetic traits are not confined to racial groups.

Gene Flow and Mixing

Gene flow refers to the transfer of genetic material between populations, which can occur through migration and interbreeding. The historical mixing of human populations has led to a complex genetic landscape, undermining the concept of distinct biological races and supporting the idea that all humans share a common ancestry.