Question

From the passage it can be inferred that the call pulse rate of male northern elephant seals in the southern rookeries was faster because:

• A. a large number of male northern elephant seals from Año Nuevo Island might have migrated to the southern rookeries to recolonise them.
• B. a large number of male northern elephant seals migrated from the southern rookeries to Año Nuevo Island in the early 1970s
• C. the male northern elephant seals of Isla Guadalupe with faster call pulse rates might have been the original settlers of the southern rookeries.
• D. the calls of male northern elephant seals in the southern rookeries have more sophisticated structures, containing doublets and triplets
• A. The call tempo of individual immigrant male seals changed to match the average tempo of resident male seals in the host colony.
• B. Besides Isla Guadalupe, there was one more founder colony with the same average male call tempo from which male seals migrated to various other colonies.
• C. The call tempo of individual male seals in host colonies changed to match the average call tempo of immigrant male seals.
• D. Besides Isla Guadalupe, there was one more surviving colony with the same average male call tempo from which no migration took place.
• A. The calls have transformed from exhibiting simple composition, great individual variety, and less regional variety to complex composition, less individual variety, and great regional variety.
• B. Owing to migrations in the aftermath of near species extinction, the average call pulse rates in the recolonised breeding locations exhibited a gradual increase until they matched the tempo at the founding colony.
• C. The calls have transformed from exhibiting simple composition, less individual variety, and great regional variety to complex composition, great individual variety, and less regional variety.
• D. Owing to migrations in the aftermath of near species extinction, the calls have transformed from exhibiting complex composition, less individual variety, and great regional variety to simple composition, less individual variety, and great regional variety.
• A. male northern elephant seals might not have exhibited dialects had they not become nearly extinct in the nineteenth century.
• B. the average call pulse rate of male northern elephant seals at Año Nuevo Island increased from the early 1970s till the disappearance of dialects.
• C. the influx of new northern elephant seals into Año Nuevo Island would have soon made the call pulse rate of its male seals exceed that of those at Isla Guadalupe.
• D. changes in population and migration had no effect on the call pulse rate of individual male northern elephant seals.

Answer 1

The Correct Option is C

From the excerpt in the fourth paragraph, a direct inference can be drawn, {"... This led Le Boeuf and his collaborator, Lewis Petrinovich, to deduce that the dialects were, perhaps, a result of isolation over time, after the breeding sites had been recolonised. For instance, the first settlers of Alio Nuevo could have had, by chance, calls with low pulse rates. At other sites, where the scientists found faster pulse rates, the opposite would have happened—seals with faster rates would have happened to arrive first.."}.
Based on this information, the sole reason for the faster call pulse rate of male northern elephant seals in the southern rookeries could be that the male northern elephant seals of Isla Guadalupe with faster call pulse rates might have been the original settlers of this region. Option A appropriately underscores this rationale and is therefore the correct answer.

So, the correct option is (C): the male northern elephant seals of Isla Guadalupe with faster call pulse rates might have been the original settlers of the southern rookeries.

Answer 2

A noticeable clue to ensure that the male northern elephant seal dialects did not disappear is presented in the penultimate paragraph: ["...At the individual level, the pulse of the calls stayed the same: A male would maintain his vocal signature throughout his lifetime. But the average pulse rate was changing. Immigration could have been responsible for this increase, as in the early 1970s, 43 per cent of the males on Alio Nuevo had come from southern rookeries that had a faster pulse rate... "].
The decline in dialects is attributed to the arrival of seals with faster pulse rates. With the ongoing population growth and continuous immigration from the original population to the islands, calls across all locations would gradually revert to the average pulse rate of the founder colony. Consequently, if the individual pulse rate of immigrants varies or adjusts to match the existing population, it could maintain the dialect in a specific region. Option A encapsulates this notion, aiding in the preservation of the existing dialect within a population. Options D and B offer minimal assistance in preventing the disappearance of dialects. Conversely, Option C aligns with the passage's discussion and contributes to the regression of dialects.

So, the correct option is (A): The call tempo of individual immigrant male seals changed to match the average tempo of resident male seals in the host colony.

Answer 3

The quoted excerpt serves as a vital reference for contrasting the characteristics of elephant seals over time, {"... Yet there are other differences between the males from the late 1960s and their great-great-grandsons: Modern males exhibit more individual diversity, and their calls are more complex. While 50 years ago the drumming pattern was quite simple and the dialects denoted just a change in tempo, Casey explained, the calls recorded today have more complex structures, sometimes featuring doublets or triplets ….}.
During the late 1960s, elephant seal calls were characterized by a basic drumming pattern, evolving over time into calls displaying significant individual diversity and complexity. Furthermore, the dialects observed in the 1960s were absent during a study conducted in the early 2010s, suggesting a decline in regional call variations. Option C effectively encapsulates these developments.

So, the correct option is (C): The calls have transformed from exhibiting simple composition,less individual variety,and great regional variety to complex composition,great individual variety,and less regional variety.

Answer 4

Let's examine each statement individually:
Option A: This inference can be drawn from the second paragraph, where it's mentioned that on recently colonized islands, the tempos of male vocal displays showed stronger differences compared to those from Isla Guadalupe, the founder colony. The passage indirectly attributes the inception of eventual dialects to the dynamic changes resulting from the near extinction of elephant seals. Hence, Option A can be inferred from the passage.
Option B: This inference can be made from the mention of the increase in pulse rate in the early 1970s due to immigration from southern rookeries and the subsequent regression of calls to the average pulse rate of the founder colony as the population continued to expand and receive immigrants. Thus, Option B can be inferred from the passage.
Option C: The passage does not support or make any claim similar to Option C.
Option D: This inference can be drawn from the fourth paragraph, where it's stated that at the individual level, the pulse of the calls remained consistent, indicating that changing variables have minimal effect on the individual vocal signature of the elephant seals. Therefore, Option D can be inferred from the passage.

So, the correct option is (C): the influx of new northern elephant seals into Año Nuevo Island would have soon made the call pulse rate of its male seals exceed that of those at Isla Guadalupe.