Question

In evolutionary terms, an Indian school boy is more closely related to
A. An Indian frog
B. An American snake
C. A Chinese horse
D. An African shark

Answer 1

Evolution is the process by which there is change in heritable characteristics of an organism. It takes place over time. Any biological population has variations within it. When evolutionary forces act on those variations, their concentration in the population either increases or decreases. This can lead to formation of new species or subspecies.

Complete step by step answer: Evolution is the process of change in heritable characteristics of a species over a few generations. It relies on evolutionary forces like natural selection and genetic drift. The new characters can be passed on from parents to offspring and can result in the formation of new species.
Common descent is an evolutionary concept. It means that all living organisms are descendants of a common ancestor. This ancestor is known as the ‘Last Universal Common Ancestor’ or LUCA. The concept of LUCA was first proposed by Charles Darwin in his book ‘On the Origin of Species’.
According to evolution of vertebrates, the common ancestor of all vertebrates was probably a marine organism with a well developed electroreceptive system. This ancestor gave rise to cartilaginous fishes like sharks and thereafter bony fishes like carps. After this, amphibians developed followed by reptiles. Reptiles evolved into birds and mammals. The first mammals are known to evolve about 200 million years ago and the first of birds are known to evolve around 150 million years ago.
Therefore, we can conclude that mammals are more closely related to birds than reptiles. Also, they are more closely related to reptiles than amphibians and distantly related to fishes.
Now, according to the question, an Indian school boy belongs to the class Mammalia. If we consider the other options, both African Shark and Indian frog belong to class Pisces and Amphibia respectively, and therefore are distantly related to the boy. The American snake is a close relative, but a Chinese horse is a mammal and therefore, the closest evolutionary relative of the Indian school boy.
So, the correct answer is “Option C”.

Note: Evolution deals with formation of heritable characters. These characters may take several generations to form and can also result in the formation of a new species. According to evolution, all living beings are descendants of a common ancestor. This concept resulted in the formation of a phylogenetic tree which can assess the closeness of present day organisms. According to the vertebrate evolution tree, mammals are more closely related to other mammals, than to reptiles or birds or amphibians or fishes.