This IELTS Academic Reading post focuses on the solutions for IELTS Cambridge 10 Test 4 Reading Passage 3 which is entitled ‘When evolution runs backwards’. This is another solution post for candidates who have big difficulties finding Reading Answers. This post can direct you to the best to comprehend every Reading answer easily. Finding IELTS Reading answers easily is a gradual process that needs attention and a good habit of reading and I hope this post can help you in this respect.

Cambridge 10 Test 4

Reading Passage 3:

The headline of the passage: When evolution runs backwards

Questions 27-31 (Multiple choice questions)

[‘Multiple choice questions’ is a common type of question set in the IELTS Reading test. It is also found in the Listening test.  Most of the time, they come with four options but sometimes there are three options. Candidates need to work hard for this type of question because this may confuse them easily in passage 2 or passage 3. There will be long answers for each question, so they may kill valuable time. So, quick reading or skimming techniques might come in handy here.  Remember that answers in 3 options out of 4 will be very close. So, vocabulary power will help a lot to choose the best answer.

TIPS: Skimming is the best reading technique. You need not understand every word here. Just try to gather the gist of the sentences. That’s all. Read quickly and don’t stop until you finish each sentence.]

Question 27: When discussing the theory developed by Louis Dollo, the writer says that –

Keywords for this question: theory, Louis Dollo,   

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^th century biologists) modified the theory of Louis Dollo.

So, the answer is: 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 for this question: humpback whale, Vancouver Island

In paragraph no. 4 we find the reference to the discovery of humpback whales, “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.

So, the answer is: D (the reason given for its unusual features)

Question 29: What is said about ‘silent genes’?

Keywords for this question: silent genes  

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

So, the answer is: C (They could lead to re-emergence of certain characteristics)

Question 30: The writer mentions the mole salamander because –

Keywords for this question: mole salamander

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 to mole salamander in paragraph no. 7. At 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 a mole salamander proves that Raff’s theory was correct.

So, the answer is: B (it suggests that Raff’s theory is correct)

Question 31: Which of the following does Wagner claim?

Keywords for this question: Wagner, claim,  

In paragraph no. 8, “According to his (Wagner’s) analysis of the Bachia family tree, the toed species re-evolved 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

So, the answer is: A (Members of the Bachia lizard family have lost and regained certain features several times)

Questions 32-36 (Matching sentence ending)

[For this type of question, candidates need to match the beginning and ending of sentences. Candidates need to look for keywords in the sentence-beginnings and find the relative paragraphs and then sentences in the passage. Skimming and scanning, both reading skills are essential for this question-type.]

Question 32: For a long time biologists rejected –

Keywords for this question: long time, biologists, rejected,  

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).

So, the answer is: F (the possibility of evolution being reversible.)

Question 33: Opposing views on evolutionary throwbacks are represented by –

Keywords for this question: opposing views, evolutionary throwbacks,  

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.

So, the answer is: G (Dollo’s findings and the convictions held by Lombroso.)

Note: here, convictions = beliefs or views

Question 34: Examples of evolutionary throwbacks have led to –

Keywords for this question: examples, evolutionary throwbacks,

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.

So, the answer is: A (the question of how certain long-lost traits could reappear.)

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

Keywords for this question: shark, killer whale,

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.

So, the answer is: B (the occurrence of a particular feature in different species.)

Question 36: One explanation for the findings of Wagner’s research is –

Keywords for this question: Wagner, research,  

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)

So, the answer is: D (the continued existence of certain genetic information.)

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

[In this type of question, candidates are asked to find out whether:

The statement in the question matches with the account in the text- YES
The statement in the question contradicts the account in the text- NO
The statement in the question has no clear connection with the account in the text- NOT GIVEN

For this type of question, you can divide each statement into three independent pieces and make your way through with the answer.]

Question 37: Wagner was the first person to do research on South American lizards.

Keywords for this question: Wagner, first, South American lizards

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 do such research is not mentioned anywhere in the passage.

So, the answer is: NOT GIVEN

Question 38: Wagner believes that Bachia lizards with toes had toeless ancestors.

Keywords for this question: Bachia lizards with toes, toeless ancestors,    

Take a look at these lines 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.

So, the answer is: YES

Question 39: The temporary occurrence of long-lost traits in embryos is rare.

Keywords for this question: temporary occurrence, long-lost traits, rare,

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.

So, the answer is: NO

Question 40: Evolutionary throwbacks might be caused by developmental problems in the womb.

Keywords for this question: Evolutionary throwbacks, might be caused, developmental problems, womb,

Again 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 the answer to the question about evolutionary throwbacks if we look at research findings about the womb.

So, the answer is: YES

Click here for solutions to Cambridge 10 Test 4 Reading Passage 1

Click here for solutions to Cambridge 10 Test 4 Reading Passage 2