Cambridge IELTS 10, Test 4, Reading Passage 3: When Evolution Runs Backwards, Solution With Answer Key

When Evolution Runs Backwards Passage Solution with Answer Key – Cambridge IELTS 10 Test 4 Reading Passage 3. Here we will discuss detailed explanation of all the questions of the passage. Here is step by step Solution with Tips and Strategies. This post is for educational purpose only. If you find difficulties in reading passage to find the right answer in the exam, just read the post carefully. Tips and strategies will help you find the right answer.

 

When Evolution Runs Backwards

IELTS Reading Passage Solution

 

IELTS Cambridge 10, Test 4  Academic Reading Module, Reading Passage 3

 

PASSAGE 3: When Evolution Runs Backwards (View Full Passage Here)

Questions 27-31 (Multiple choice questions)

** Tips (link details): How To Solve Multiple Choice Questions in IELTS Reading Module?

Question 27: When discussing the theory developed by Louis Dollo, the writer says that –
Keywords: theory, Louis Dollo,
Now, we find the mention of Louis Dollo in paragraph no. 3. Here, in lines 2-13, the writer says, “… . ..a Belgian palaeontologist called Louis Dollo was studying fossil records and coming to the opposite conclusion. In 1890, he proposed that evolution was irreversible: that ‘an organism is unable to return, even partially, to a previous stage already realised in the ranks of its ancestors’. Early 20th-century biologists came to a similar conclusion, though they qualified it in terms of probability, stating that there is no reason why evolution cannot run backwards – it is just very unlikely.”
Here, they qualified it in terms of probability = they (20 century biologists) modified the theory of Louis Dollo.
Answer: C (it was modified by biologists in the early twentieth century)

Question 28: The humpback whale caught off Vancouver Island is mentioned because of –
Keywords: humpback whale, Vancouver Island;
Now, in paragraph no. 4 we find the reference of the discovery of humpback whale., “In 1919, for example, a humpback whale with a pair of leg-like appendages over a metre long, complete with a set of limb bones, was caught off Vancouver Island in Canada. Explorer Roy Chapman Andrews argued at the time that the whale must be a throwback to a land-living ancestor.” This argument of Andrews is quite opposite to the theory presented by Dollo’s law. Therefore, we need to understand that the humpback whale is mentioned here because of its strange / unusual features.
Answer: D (the reason given for its unusual features)

Question 29: What is said about ‘silent genes’?
Keywords: silent genes;
Now, in paragraph no. 5, the last lines give us the answer, “They reasoned that while some evolutionary changes involve the loss of genes and are therefore irreversible, others may be the result of genes being switched off. If these silent genes are somehow switched back on, they argued, long-lost traits could reappear.”
The lines mean that ‘silent genes’ could lead to the re-emergence of certain characteristics.
Here, characteristics = traits and re-emerge = reappear;
Answer: C (They could lead to re-emergence of certain characteristics)

Question 30: The writer mentions the mole salamander because –
Keywords: mole salamander;
Now, in paragraph no. 6, the writer mentions Rudolf Raff’s 10-million year time frame of the survival of silent genes. Then, we find the reference of mole salamander in paragraph no. 7. In the end of paragraph no. 7, the writer says, “The salamander example fits with Raff’s 10-million-year time frame.”
Here, fits = matches;
This means that the example of mole salamander was given to prove that Raff’s theory was correct.
Answer: B (it suggests that Raff’s theory is correct)

Question 31: Which of the following does Wagner claim?
Keywords: Wagner, claim,
Now, in paragraph no. 8, “According to his (Wagner’s) analysis of the Bachia family tree, the toed species reevolved toes from toeless ancestors and, what is more, digit loss and gain has occurred on more than one occasion over tens of millions of years”
So, the lines suggest Wagner claims that members of the Bachia lizard family have lost and regained certain features more the one time.
Here, several times = on more than one occasion;
Answer: A (Members of the Bachia lizard family have lost and regained certain features several times)

 

---

 

Questions 32-36 (Matching sentence ending)

** Tips (link details): How to Solve Sentence Completion Questions in IELTS Reading Module?

Question 32: For a long time biologists rejected –
Keywords: long time, biologists, rejected,
Now, in paragraph no. 1, take a look at lines 3-6, “.. .. .. For the better part of a century, most biologists have been reluctant to use those words, mindful of a principle of evolution that says ‘evolution cannot run backwards’…”.
Here, ‘those words’ indicate to the words in the previous lines ‘evolutionary throwback’.
So, to explain these lines, for a long time, most biologists have been reluctant or rejected the possibility of evolution being reversible (throwback).
Answer: F (the possibility of evolution being reversible.)

Question 33: Opposing views on evolutionary throwbacks are represented by –
Keywords: opposing views, evolutionary throwbacks,
Now, in lines 1-4 of paragraph no. 3, the writer states, “While Lombroso was measuring criminals; a Belgian palaeontologist called Louis Dollo was studying fossil records and coming to the opposite conclusion.”
The lines suggest that Lombroso and Dollo were studying different fields but they were also studying the same theory whether evolution could reappear. But their conclusions or findings were opposing.

Answer: G (Dollo’s findings and the convictions held by Lombroso.)

Question 34: Examples of evolutionary throwbacks have led to –
Keywords: examples, evolutionary throwbacks,
Now, in the first few lines of paragraph no. 5, the author states, “Since then, so many other examples have been discovered that it no longer makes sense to say that evolution is as good as irreversible. And this poses a puzzle: how can characteristics that disappeared millions of years ago suddenly reappear?”
This means the examples have led us to the puzzle or question about the reappearance of long-lost traits or characteristics.
Answer: A (the question of how certain long-lost traits could reappear.)

Question 35: The shark and killer whale are mentioned to exemplify –
Keywords: shark, killer whale,

Now, in paragraph 9 the writer mentions, “One possibility is that these traits are lost and then simply reappear, in much the same way that similar structures can independently arise in unrelated species, such as the dorsal fins of sharks and killer whales.” These lines suggest that the shark and killer whale are mentioned to exemplify the occurrence of a particular feature in different or unrelated species.
Answer: B (the occurrence of a particular feature in different species.)

Question 36: One explanation for the findings of Wagner’s research is –
Keywords: Wagner, research,
Now, in paragraph 9 the writer mentions, “Another more intriguing possibility is that the genetic information needed to make toes somehow survived for tens or perhaps hundreds of millions of years in the lizards and was reactivated.”
This means an explanation of Wagner’s research is that the continuous existence (survived for tens or perhaps hundreds of millions of years).
Answer: D (the continued existence of certain genetic information.)

---

 

Questions 37-40 (YES/NO/NOT GIVEN)

** Tips (link details): How To Solve Yes, No, Not Given Question in IELTS Reading Module?

Question 37: Wagner was the first person to do research on South American lizards.
Keywords: Wagner, first, South American lizards;
Now, studying the passage we can learn that Wagner did research on South American research (paragraph no. 8). However, whether Wagner was the first person to such research is not mentioned anywhere in the passage.
Answer: NOT GIVEN

Question 38: Wagner believes that Bachia lizards with toes had toeless ancestors.
Keywords: Bachia lizards with toes, toeless ancestors,
Now, in paragraph 8, “According to his analysis of the Bachia family tree, the toed species re-evolved toes from toeless ancestors…” These lines suggest that the statement is true.
Answer: YES

Question 39: The temporary occurrence of long-lost traits in embryos is rare.
Keywords: temporary occurrence, long-lost traits, rare,
Now, in the last paragraph, the writer mentions in lines 4-5,“Early embryos of many species develop ancestral features.”
These lines suggest that the temporary occurrence of long-lost traits (ancestral features) in embryos is not rare as it happens in many species.
Answer: NO

Question 40: Evolutionary throwbacks might be caused by developmental problems in the womb.
Keywords: Evolutionary throwbacks, might be caused, developmental problems, womb,
Now, in the last paragraph, look at lines 1-4, “But if silent genes degrade within 6 to 10 million years, how can long-lost traits be reactivated over longer time scales? The answer may lie in the womb.”
The lines suggest that we find answer to the question about evolutionary throwbacks if we look at research findings about the womb.
Answer: YES

 

 

View Full Passage Here

 

 

Answer Key – When Evolution Runs Backwards

Cambridge IELTS 10 Test 4 Answer Key, Reading Passage 3

 

When Evolution Runs Backwards Reading Passage Answers Keys

Passage 3

 

 

 

• Cambridge IELTS 10, Test 4, Reading Passage 1: The Megafires of California, Solution With Answer Key
• Cambridge IELTS 10, Test 4, Reading Passage 2: Second Nature, Solution With Answer Key