Passage

Natural selection cannot anticipate future environments on the earth. Therefore, the set of existing organisms can never be fully prepared for environmental catastrophes that await life. An outcome of this is the extinction of those species which cannot overcome environmental adversity. This failure to survive, in modern terms, can be attributed to the genomes which are unable to withstand geological vagaries or biological mishaps (infections, diseases and so on). In biological evolution on the earth, extinction of species has been a major feature. The earth may presently have up to ten million species, yet more than 90% of species that have ever lived on the earth are now extinct. Once again, the creationist doctrines fail to satisfactorily address why a divine creator will firstly bother to create millions of species and then allow them to perish. The Darwinian explanation for extinct life is once again simple, elegant and at once convincing—organisms go extinct as a function of environmental or biological assaults for which their inheritance deems them ill-equipped. Therefore, the so-called Darwinian theory of evolution is not a theory at all. Evolution happens—this is a fact. The mechanism of evolution (Darwin proposed natural selection) is amply supported by scientific data. Indeed, to date no single zoological, botanical, geological, paleontological, genetic or physical evidence has refuted either of the central two main Darwinian ideas. If religion is not taken into consideration, Darwinian laws are acceptable just like the laws proposed by Copernicus, Galileo, Newton and Einstein—sets of natural laws that explain natural phenomena in the universe.

The passage suggests that Darwinian theory of evolution is not a theory at all because

(a) it does not satisfy the creationist doctrine
(b) extinction is a function of environment and biological assaults ✓ UPSC's answer
(c) there are no evidences to refute it
(d) existence of organisms is attributed to a creator

Why the answer is (b)

• The passage explicitly states that the Darwinian explanation for extinct life is that organisms go extinct as a function of environmental or biological assaults for which their inheritance deems them ill-equipped.

• Immediately following this explanation, the author concludes: 'Therefore, the so-called Darwinian theory of evolution is not a theory at all.'

• The author argues that because the mechanism (natural selection leading to extinction via environmental/biological factors) is amply supported by scientific data and is a fact, it functions as a law rather than a mere theory.

• The text compares Darwinian laws to the laws of Copernicus, Galileo, Newton, and Einstein, which are sets of natural laws explaining phenomena, not just theories.

• Thus, the reason it is 'not a theory at all' is tied to the factual, law-like nature of the mechanism where extinction results from environmental and biological assaults.

Why the other options are wrong

(a) it does not satisfy the creationist doctrine: The passage mentions creationist doctrines only to highlight their failure to explain extinction, not as the reason Darwinian theory is classified as a law rather than a theory.
(c) there are no evidences to refute it: While the passage notes that no evidence has refuted Darwinian ideas, the specific sentence linking the 'not a theory' conclusion follows the explanation of extinction as a function of environmental and biological assaults.
(d) existence of organisms is attributed to a creator: The passage argues against the idea that existence is attributed to a creator, stating that Darwinian laws explain natural phenomena without religious consideration, but this is not the specific reason given for the 'not a theory' classification.

Asked in the CSAT Paper II of the UPSC Civil Services Preliminary Examination 2022, held on 5 June 2022. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.