Question

A scientist analyzes the insulin molecules, which are proteins, of three different species, A, B, and C. The insulin from A is different from B in six ways and from C in three ways. The insulin from B is different from C in two ways. Which of the two species appear to be the most closely related? Explain your answer.

Answer 1

Species A and B appear to be the most closely related.

Step-by-step explanation:

Insulin, being a protein, exhibits variations in its molecular structure among different species. The given information indicates the number of differences in the insulin molecules of species A, B, and C. To determine the most closely related species, we need to identify the pair with the fewest differences.

Species A differs from B in six ways and from C in three ways, while B differs from C in two ways. To find the cumulative difference between A and C, we add the differences between A and B (6) and B and C (2): 6 + 2 = 8. Therefore, species A and C differ in a total of 8 ways.

On the other hand, species A and B differ in 6 ways. Comparing these values, we can see that species A and B have fewer differences (6) than species A and C (8). Hence, species A and B are more closely related. The reasoning behind this lies in the principle of evolutionary relationships, where fewer differences in molecular structures indicate a more recent common ancestor.

In conclusion, based on the analysis of insulin molecules, species A and B appear to be the most closely related, as they exhibit the fewest differences in their insulin structures. This suggests a closer evolutionary relationship between species A and B compared to species A and C.