The statement “Spiders do not have eight legs” is incorrect; spiders do have eight legs as a defining characteristic of arachnids. Similarly, insects typically have six legs. In evolutionary terms, traits that evolve later (derived traits) arise after a common ancestor. Since spiders evolved before insects, they possess the ancestral trait (eight legs) rather than a derived trait. Thus, the assertion that spiders do not have derived traits is valid, as they retain the original trait from their evolutionary lineage.

In summary, spiders have eight legs, and the notion that they do not have derived traits because they evolved first is consistent with evolutionary biology.