A clade is defined as?

A clade is defined as?

• A. A random sample of organisms.
• B. A classification based only on physical appearance.
• C. A diagram showing evolutionary relationships.
• D. A group consisting of a common ancestor and all its descendants.

Answer: (D)

In evolutionary biology, a clade is a group that includes a common ancestor and all of its descendants. This makes it a monophyletic unit, capturing the entire lineage that arose from that ancestor. That clarity is why this description is the best: it directly reflects true ancestry and evolutionary relationships, not just shared traits or appearances. If you left out some descendants, or grouped organisms by superficial similarity alone, you wouldn’t have a clade. A diagram showing evolutionary relationships helps visualize these lineages, but the defining idea of a clade is the ancestor plus every descendant it spawned.

In evolutionary biology, a clade is a group that includes a common ancestor and all of its descendants. This makes it a monophyletic unit, capturing the entire lineage that arose from that ancestor. That clarity is why this description is the best: it directly reflects true ancestry and evolutionary relationships, not just shared traits or appearances. If you left out some descendants, or grouped organisms by superficial similarity alone, you wouldn’t have a clade. A diagram showing evolutionary relationships helps visualize these lineages, but the defining idea of a clade is the ancestor plus every descendant it spawned.