The lost animals of Australia
Read The lost animals of Australia and check the IELTS Reading answers. The history of Australia's animals over the past 50,000 years has been largely one of extinction. The time has been too short for new species of large animals to evolve and, over this period, nearly one- third of Australia's ma…
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The history of Australia's animals over the past 50,000 years has been largely one of extinction. The time has been too short for new species of large animals to evolve and, over this period, nearly one- third of Australia's mammal species have become extinct, along with nearly all the large reptiles and many of the flightless birds. The cause of these extinctions is still hotly debated. One school of thought suggests that humans caused the extinctions, and another that they were due to changes in climate. The greatest problem in evaluating these theories is that we do not know exactly when these animals became extinct. Fossils from a number of well- dated cave and lakeside sites suggest that all the now-extinct species had already vanished 35,000 years ago, but a few other sites suggest that giant marsupials might have survived until 25,000 years ago, or even as late as 6,000 years ago.
Answers with explanations
- 27. C
The writer explains that the biggest hurdle in deciding what caused the extinctions is establishing an exact timeline. Some **fossil evidence** points to 35,000 years ago, while other sites suggest 25,000 or 6,000 years ago. Because the fossil record provides conflicting dates, option **C** (the evidence is somewhat contradictory) is correct.
- 28. A
The text specifically attributes the smaller size of Australia's **larger mammals** compared to those in Africa and Asia to poor soils and erratic climate. Because these environmental conditions "limit plant growth," they result in an **insufficient supply of food** for the animals. Option **A** correctly matches this reasoning.
- 29. C
The passage highlights that mammalian carnivores were at a disadvantage due to limited prey. **Reptiles** became the dominant large carnivores because their cold-blooded nature meant they "required less energy," allowing them to survive more easily in Australia's harsh, low-resource environment. This matches option **C** (they were more suited to the environment).
- 30. C
According to the writer, the **first humans** had a profound impact because Australian animals were only used to escaping "relatively unintelligent reptiles." When faced with humans, they lacked the necessary survival behaviors because they had **little experience in escaping from such skillful hunters**. Option **C** accurately reflects this.
- 31. A
The text observes a general trend where most large Australian species shrank in size over time. However, it explicitly notes an "exception" for **humans** and **wombats**. Because both species did not shrink, they share the common trait that their **size has remained the same**, which aligns with option **A**.
- 32. C
The passage theorizes that **Australian mammals have become smaller** because human hunters selectively targeted and "claimed the largest individuals." By removing the biggest animals, only the smaller ones survived to reproduce. Option **C** ("bigger examples of the species were killed") perfectly captures this dynamic.
- 33. A
In the opening paragraph, the writer explains that the lack of newly evolved **large mammals** in Australia is simply because "The time has been too short". This directly corresponds to ending **A**, which states the **failure to evolve** is because "not enough time has passed."
- 34. F
The passage identifies the unknown **extinction date** as the "greatest problem" in evaluating why the animals vanished. Because the exact timeline remains unknown, it is a critical issue that has not been figured out, perfectly matching ending **F** ("is a crucial factor that has yet to be resolved").
- 35. E
The text proposes that in prehistoric times, naturally occurring fires were "less frequent" (**a reduction**) because a huge population of **large marsupial herbivores** constantly ate the vegetation, leaving less fuel for fires. This links directly to ending **E** ("is theoretically based on a large herbivore population").
- 36. D
The passage notes that the **arrival of humans** in pristine, previously uninhabited areas (like Hawaii and Antarctica) invariably causes a "profound impact," specifically leading to massive species destruction. This matches ending **D** ("is often responsible for a significant number of extinctions").
- 37. NO
The text explicitly states that the **mass extinction** affected not just large mammals, but also "nearly all the large reptiles" and "many of the flightless birds." Because the extinctions were definitely not **limited to giant mammals**, the statement is **NO**.
- 38. NOT GIVEN
While the passage notes that **Australia's climate** experienced an "extremely arid phase" (dry period) and that **humans** arrived about **50,000 years ago**, it never explicitly states that the climate became **cooler** at that 50,000-year mark. Therefore, the statement is **NOT GIVEN**.
- 39. YES
The text states that the larger **Australian carnivores** were all reptiles, and the **largest** of these reptiles were the gigantic snakes of the genus **Wonambi**. Logically, if the large carnivores were reptiles, and Wonambi was the largest reptile, then Wonambi was the **biggest** carnivore overall. Thus, the statement is **YES**.
- 40. YES
The passage confirms that following the **arrival of Europeans**, the extinction pattern shifted, and as a direct result, "a large number of smaller species also became extinct". Because Europeans **caused the extinction** of these **smaller Australian mammals**, the statement is **YES**.