Question

The wing of a bird and human arm perform different functions but have the same embryonic origin. Such structures are known as
A. Homologous structures
B. Analogous characters
C. Vestigial structures
D. Adaptive structures
E. Derived traits

Answer 1

Hint:- Adaptation of an organism to its surroundings or habitat requires modification or specialization of an organ to sustain in the prevailing conditions. Divergent evolution is an evolutionary phenomenon in which the organisms who have a common origin diverge in separate lines of evolution and gradually evolve into new evolutionary groups or species.

Complete step-by-step solution:- Bird and humans both are vertebrates. Both share a common ancestor and have a similar embryonic origin. Both organisms are examples of divergent evolution. The wing of a bird is a modified forelimb. It is adapted for an aerial mode of living i.e. used for flying. Whereas, the forelimb in humans is called an arm. It is used for various purposes like holding, clutching, lifting, writing, etc. Although both the wing and arm are morphologically different and perform different functions but anatomically they resemble each other. They show similarities in the pattern of bones of forelimbs. They have the same set of bones i.e. humerus, radius, ulna, and phalanges. This is because genetically, both these structures originate from the same structure of the last common ancestor.
In evolutionary biology, when a trait or phenotypic character from a common ancestor continues its expression in all members of the taxa through an evolutionary lineage is known as homology.
Such traits or structures descending from a common ancestor have a similar embryonic origin but perform different functions known as homologous structures.
So, the correct answer is (A), homologous structures.

Note:- Richard Owen in 1843 first defined the concept of homology. Later, Charles Darwin in 1859 explained homology in his theory of evolution. Opposite of homologous structures are analogous structures. These structures have similar functions but must have evolved independently in each lineage after diverging from a common ancestor without the character.