What does the Pancrustacea Hypothesis propose about the relationship between hexapods and crustaceans?

• A. The hypothesis that crustaceans are not related to hexapods
• B. Hexapods evolved independently of crustaceans
• C. Hexapods are more closely related to myriapods than to crustaceans
• D. The hypothesis that hexapods and crustaceans are more closely related to each other than to myriapods

Answer: (D)

The main idea tested is that hexapods and crustaceans form a close genetic and evolutionary lineage, more recently related to each other than either is to myriapods. The Pancrustacea hypothesis groups hexapods (insects and their relatives) with crustaceans into a single clade within Euarthropoda, implying that hexapods evolved from crustacean-like ancestors. This view is supported by large-scale molecular studies and aligns with shared developmental and anatomical features that suggest a common origin for these two groups. In contrast, ideas that crustaceans aren’t related to hexapods, or that hexapods evolved independently, or that hexapods are closer to myriapods, don’t fit the combined genetic and embryological evidence. So, hexapods and crustaceans are more closely related to each other than to myriapods.