What term describes the forelimb bones of a bird, bat, horse, whale and human? synapomorphy analogous apomorphy homologous
The correct answer and explanation is:
The correct answer is homologous.
Explanation:
The forelimb bones of a bird, bat, horse, whale, and human are considered homologous structures. This means that these bones share a common evolutionary origin, even though they may have different functions and appearances in the adult organisms.
- Homologous structures are anatomical features in different species that originated from a common ancestor. They might look different or serve different purposes due to divergent evolution but have the same underlying structural framework. For example, the forelimbs of all these animals have similar bone arrangements—humerus, radius, ulna, carpals, metacarpals, and phalanges—reflecting their shared ancestry.
- In contrast, analogous structures perform similar functions but do not share a common ancestry or structure. For example, the wings of insects and birds both serve the purpose of flight but evolved independently, making them analogous, not homologous.
- A synapomorphy is a shared derived trait that is unique to a particular clade or group, indicating a close evolutionary relationship. While the forelimb structure can be part of a synapomorphy for certain groups, the term is more specific to traits defining a clade rather than describing general homology.
- An apomorphy is a derived characteristic or trait that is unique to a particular species or group. It contrasts with a plesiomorphy, which is an ancestral trait. The term doesn’t directly describe the relationship between the forelimbs across these species.
Summary:
The forelimb bones in these animals—bird, bat, horse, whale, and human—are homologous because they come from the same ancestral limb structure, despite evolving to perform different functions like flying, running, swimming, or manipulating objects. This concept is fundamental in evolutionary biology to understand how diverse organisms are related through common ancestry.