The extinct earliest known ancestor of the cheetah, a large cat now found only in Africa, lived only in what...
GMAT Critical Reasoning : (CR) Questions
The extinct earliest known ancestor of the cheetah, a large cat now found only in Africa, lived only in what is now western North America when the two continents were conjoined, as fossil skeletons found in North America but nowhere else indicate. That ancestor shared certain skeletal features with the cheetah but with no other cat.
If all of the information above is true, which of the following hypotheses does it most strongly support?
Passage Visualization
| Passage Statement | Visualization and Linkage |
| The extinct earliest known ancestor of the cheetah, a large cat now found only in Africa, lived only in what is now western North America when the two continents were conjoined | Establishes: Geographic distribution patterns
Key insight: Complete geographic separation between ancestor and descendant locations |
| as fossil skeletons found in North America but nowhere else indicate | Establishes: Evidence source and exclusivity
Confirms: Ancestor population was geographically isolated |
| That ancestor shared certain skeletal features with the cheetah but with no other cat | Establishes: Evolutionary relationship specificity
|
| Overall Implication | Pattern Revealed: Geographic migration with evolutionary continuity The evidence shows a specific cat lineage that:
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Valid Inferences
Inference: The cheetah lineage originated in western North America and subsequently migrated to Africa.
Supporting Logic: Since the earliest known cheetah ancestor lived exclusively in western North America (as evidenced by fossils found only there) and shared unique skeletal features only with modern cheetahs (not with any other cat species), this demonstrates a direct evolutionary lineage that moved from North America to Africa. The geographic separation between ancestor location (North America) and descendant location (Africa), combined with the maintained species-specific skeletal characteristics, indicates migration of this lineage between continents.
Clarification Note: This inference is supported by the fossil evidence and anatomical similarities, but the passage does not provide information about the timing, mechanism, or specific route of migration.
This focuses on the cheetah's efficiency as a predator based on skeletal features. However, the passage doesn't discuss predatory abilities or hunting efficiency at all. The skeletal features mentioned are used to establish evolutionary relationships, not to evaluate predatory effectiveness. This choice introduces information not supported by the passage.
This suggests we can reconstruct an animal's outward appearance from skeletal structure. The passage only discusses skeletal features for establishing evolutionary relationships between the ancestor and modern cheetah. It makes no claims about reconstructing external appearance or what the animals looked like on the outside.
This claims the cheetah's skeletal structure remained completely unchanged. While the passage says the ancestor 'shared certain skeletal features' with modern cheetahs, this doesn't mean the structure remained entirely unchanged - only that some features were shared. The word 'certain' suggests partial, not complete, similarity.
This makes a claim about nonskeletal features (things like fur, behavior, etc.) having few similarities between ancestor and modern cheetah. However, the passage provides no information about nonskeletal characteristics at all. We cannot infer anything about features not discussed in the evidence.
This directly follows from the evidence. The earliest ancestor lived only in western North America (where all fossils were found), shared unique skeletal features only with modern cheetahs (establishing direct lineage), and modern cheetahs live only in Africa. The geographic separation between ancestor location and descendant location, combined with maintained species-specific traits, most strongly supports migration from North America to Africa.