Question

mr. morales is teaching a lesson on classification. he says that spiders are classified as a different group than insects because they have eight legs instead of six legs. he explains that spiders evolved first. mr. morales also says that having eight legs is the derived trait that separates the two groups. antonio thinks mr. morales is wrong. which piece of information is antonio considering?
spiders do not have derived traits, since they evolved first.
spiders do not have eight legs.
insects do not have six legs.
if spiders evolved first, six legs is the derived trait.

Explanation:

To determine the correct answer, we analyze the concept of derived traits. A derived trait is a characteristic that appears in a descendant group and differs from the ancestral trait. If spiders evolved first (meaning their trait - eight legs - is ancestral), then the trait that appears later (six legs in insects) would be the derived trait.

• Option 1: Spiders can have derived traits, so this is incorrect.
• Option 2: Spiders do have eight legs, so this is wrong.
• Option 3: Insects do have six legs, so this is incorrect.
• Option 4: If spiders evolved first, the trait that comes later (six legs in insects) is the derived trait, which is the reasoning Antonio is considering.

Answer:

If spiders evolved first, six legs is the derived trait.