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Multiple Choice
Which of the following groups represents the most basal lineage of vertebrates?
A
Cartilaginous fishes (Chondrichthyes)
B
Ray-finned fishes (Actinopterygii)
C
Hagfishes (Myxini)
D
Amphibians (Amphibia)
Verified step by step guidance
1
Understand the term 'basal lineage': In evolutionary biology, a basal lineage refers to the earliest diverging group within a clade. It represents the most primitive or ancestral traits compared to other groups in the clade.
Identify the clade in question: The problem is asking about vertebrates, which are animals with a backbone or a notochord during development.
Review the evolutionary relationships of the groups listed: Hagfishes (Myxini) are jawless vertebrates and lack many of the derived traits seen in other vertebrates, such as jaws and paired fins. This makes them more primitive compared to the other groups listed.
Compare the traits of the other groups: Cartilaginous fishes (Chondrichthyes) and ray-finned fishes (Actinopterygii) both have jaws and paired fins, which are more derived traits. Amphibians (Amphibia) are tetrapods, which are even more derived as they have adaptations for life on land.
Conclude that hagfishes (Myxini) represent the most basal lineage of vertebrates because they retain the most ancestral traits and diverged earlier in the evolutionary history of vertebrates compared to the other groups listed.