Passage for Questions 6-10

II. There were humans long before there was history. The archaic humans loved, played, formed close friendships and competed for status and power, but so did chimpanzees, baboons and elephants. There was nothing special about them. Nobody, least of all humans themselves, had any inkling that their descendants would one day walk on the moon, split the atom, fathom the genetic code and write history books. The most important thing to know about prehistoric humans is that they were incognisant animals with no more impact on their environment than gorillas, fireflies or jellyfish. Biologists classify organisms into species.

Animals are said to belong to the same species if they tend to mate with each other, giving birth to fertile offspring. Horses and donkeys have a recent common ancestor and share many physical traits. They will mate if induced to do so but their offspring, called mules, are sterile. Mutations in donkey DNA can therefore never cross over to horses, or vice versa. The two types of animals are consequently considered two distinct species, moving along separate evolutionary paths. By contrast, a bulldog and a spaniel may look very different, but they are members of the same species, sharing the same DNA pool. [203 words] (Extracted from Sapiens: A Brief History of Humankind by Yuval Noah Harari)

According to the passage, what determines whether two animals belong to the same species?

Correct Answer: Their ability to produce fertile offspring

Step-by-Step Explanation:

1. Understand the Question:

The question asks to identify what determines whether two animals belong to the same species based strictly on the provided passage.

2. Analyze the Passage:

Looking at the second paragraph of the text:

"Animals are said to belong to the same species if they tend to mate with each other, giving birth to fertile offspring."

The passage also provides an example comparing horses and donkeys. Although they can mate, their offspring (mules) are sterile, making them distinct species. In contrast, dogs like bulldogs and spaniels belong to the same species because they share the same DNA pool and can reproduce fertile offspring.

3. Evaluate the Options:

• Option 1: Their ability to produce fertile offspring – This directly aligns with the definition explicitly stated in the passage.
• Option 2: Their physical appearance and size – The passage contradicts this by pointing out that a bulldog and a spaniel look very different but belong to the same species.
• Option 3: Their shared evolutionary ancestor – The passage states that horses and donkeys share a recent common ancestor, yet they are distinct species.
• Option 4: Their capacity to adapt to the environment – This is not mentioned in the passage as the criterion for defining a species.

Conclusion:

Therefore, according to the passage, two animals belong to the same species based on their ability to mate and produce fertile offspring.