Similar structures that related species have inherited from a common ancestor.

Similar structures that related species have inherited from a common ancestor.

• A. Vestigial organ
• B. Geographic isolation
• C. Homologous structures
• D. Embryology evidence

Answer: (C)

Homologous structures show shared ancestry. Related species inherit a common anatomical pattern from a single ancestor, so their limbs or organs are built from the same underlying bone arrangement even if they serve different functions today. For example, the forelimbs of humans, bats, whales, and dogs all have a similar bone layout (shoulder region, upper arm, forearm bones, and wrist/hand bones), but each is adapted for different uses like grasping, flying, or swimming. This shared structural plan is evidence of descent with modification from a common ancestor. Vestigial organs are remnants that have lost function, not the general pattern of similar structures across related species. Embryology and geographic isolation are related ideas in evolution, but the term that best fits the description of inherited, similar structures is homologous.

Homologous structures show shared ancestry. Related species inherit a common anatomical pattern from a single ancestor, so their limbs or organs are built from the same underlying bone arrangement even if they serve different functions today. For example, the forelimbs of humans, bats, whales, and dogs all have a similar bone layout (shoulder region, upper arm, forearm bones, and wrist/hand bones), but each is adapted for different uses like grasping, flying, or swimming. This shared structural plan is evidence of descent with modification from a common ancestor. Vestigial organs are remnants that have lost function, not the general pattern of similar structures across related species. Embryology and geographic isolation are related ideas in evolution, but the term that best fits the description of inherited, similar structures is homologous.