Final answer:
The evidence not based on observation is C. The rainfall totals in the summer are half of those in the spring, as it implies statistical analysis rather than direct observation.
Step-by-step explanation:
The evidence not resulting from an observation in the context of the scenarios provided is: C. The rainfall totals in the summer are half of the totals in the spring. This statement is more likely derived from measured data or statistics rather than a direct observation. An observation, in contrast, would be similar to B. The arrowhead fossils all have the same shape, which can be determined by looking at the fossils.
Examples of evidence supporting various hypotheses might include: continental drift, volcanic eruptions, or the relative abundance of fern spores at the Cretaceous-Paleogene boundary indicating changes in biodiversity. When drawing conclusions from fossil records, we often look for information about extinction of species or changes in their morphology over time. Critical thinking about such fossils could point to significant geological events or environmental shifts like mountain building or earthquakes.