Final answer:
The statement that there is greater variation within traditional racial groups than between them is true. Biological and genetic research shows that variation is greater within races, challenging the validity of race as a biological concept.
Step-by-step explanation:
It is true that there is much greater variation within each of the traditional so-called races than between them. The concept of race, from a biological and genetic standpoint, is no longer considered a valid or accurate representation of human diversity. Genetic studies have consistently shown that there is more variation within so-called racial groups than between them. Furthermore, only a small portion of our genetic markers, such as those for skin pigmentation, correlate with the categories used to classify race. Variations such as traits in skin color, hair texture, and facial features do not create distinct groups but exist along spectrums that overlap considerably among individuals. Therefore, race fails as a logical or statistical construct for categorizing human genetic diversity.