Read the passage below and evaluate the statement that follows.
For decades, comparative psychologists attributed the sophisticated tool-manufacturing abilities of New Caledonian crows (Corvus moneduloides) strictly to cumulative cultural evolution, akin to human technological transmission. Proponents of this cultural transmission model pointed to regional variations in the design of stepped cut-leaf tools as evidence of localized traditions passed down across generations through social learning. However, recent longitudinal studies on hand-reared, socially isolated individuals have challenged this consensus. Juveniles raised without exposure to adult tutors or pre-fabricated tools nevertheless demonstrated the spontaneous development of functional tool-shaping behaviors, constructing rudimentary stepped tools from Pandanus leaves identical in mechanical logic to those found in the wild.
These findings suggest that while social learning may refine motor precision, the foundational cognitive scripts and motor patterns for tool geometry are genetically canalized rather than culturally inherited. Skeptics of the genetic model contend that isolated juveniles still require environmental exposure to raw leaf materials, arguing that interaction with the physical medium acts as a catalyst for cognitive mapping. Yet this objection fails to distinguish between environmental triggers necessary for gene expression and social transmission of novel information. Because the structural template of the tool emerges independently of observational learning, the claim that regional variation uniquely demonstrates cumulative culture remains unpersuasive; such variation could equally reflect localized micro-adaptations to vegetation rigidity.
Statement: Based on the passage, the author's argument implies that regional variations in New Caledonian crow tool design cannot serve as conclusive evidence for cumulative cultural transmission because such variations can be accounted for by environmental factors without requiring social learning.
Answer: Answer