What is an important aspect of the Grand Canyon's stratigraphy?

The correct choice emphasizes that the Grand Canyon's stratigraphy reveals the geological history and changes over millions of years. This aspect is crucial because the layers of rock and sediment exposed in the canyon provide a natural record of the Earth's geological processes, including sediment deposition, erosion, volcanic activity, and tectonic movements.

By studying these stratified layers, geologists can reconstruct the environmental conditions that existed at different times in the Earth's history, which helps in understanding how the landscape has transformed over time. Each layer corresponds to a specific geological time period, allowing scientists to make inferences about the climate, organisms, and geological events that existed when these layers were formed.

The other options do not accurately reflect the significance of stratigraphy in the Grand Canyon. For example, the current species present would only provide a snapshot of biodiversity and would not convey any historical geological changes. Similarly, human impacts and modern weather patterns, while important, do not pertain to the natural geological record that stratigraphy represents. Thus, the geological history captured within the canyon makes it an invaluable resource for understanding Earth's past.