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.

According to the passage, natural selection cannot anticipate future environments on the earth as 1. species not fully prepared to face the environmental changes that await them will face extinction 2. all the existing species would get extinct as their genomes will not withstand biological mishaps 3. inability of the genome to withstand environmental changes would result in extinction 4. extinction of species is a common feature Select the correct answer using the code given below.

(a) 1, 2 and 3
(b) 2, 3 and 4
(c) 1, 3 and 4 ✓ UPSC's answer
(d) 1, 2 and 4

Why the answer is (c)

• The passage states that natural selection cannot anticipate future environments, so existing organisms can never be fully prepared for environmental catastrophes.

• It then says an outcome is extinction of those species which cannot overcome environmental adversity, supporting statement 1.

• It attributes failure to survive to genomes unable to withstand geological vagaries or biological mishaps, supporting statement 3.

• It says extinction of species has been a major feature and more than 90% of species that have ever lived are now extinct, supporting statement 4.

• Statement 2 is false because it says all existing species would get extinct, while the passage says only those unable to overcome adversity go extinct.

• Therefore, statements 1, 3 and 4 are correct, so option (c) follows.

Why the other options are wrong

(a) 1, 2 and 3: Option (a) is wrong because it includes statement 2, which incorrectly says all existing species would get extinct.
(b) 2, 3 and 4: Option (b) is wrong because it includes statement 2 and omits statement 1, which the passage directly supports.
(d) 1, 2 and 4: Option (d) is wrong because it includes statement 2 and omits statement 3, which the passage directly supports.

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.