Final answer:
To test whether Athyris started to exist during Phacops' timeline, a stratigraphic analysis, examination of the fossil record, radiometric dating, morphology studies, and analysis of paleoenvironmental conditions can be used to establish the relative and absolute ages of Athyris and Phacops fossils.
Step-by-step explanation:
To test the hypothesis that Athyris is a new organism that started to exist partway through Phacops' existence using fossils and rocks, we can take the following steps:
- Conduct stratigraphic analysis to ascertain the relative ages of rocks containing Athyris and Phacops fossils. Since sedimentary rocks are deposited in layers over time, the position of the fossil within these layers can indicate relative age.
- Study the fossil record extensively to identify the first appearance of Athyris fossils. This involves examining multiple geographic locations and correlating the data to see if Athyris appears globally at a certain stratigraphic level, thereby supporting the timeline of its existence relative to Phacops.
- Utilize radiometric dating techniques to determine an absolute age for the rock layers in question, which can confirm the hypothesis if the dates align with the proposed timeline of Athyris and Phacops.
- Comparative anatomy and morphology studies could also be conducted to analyze the physical characteristics of these fossils. Distinct features that arise in Athyris fossils could suggest evolutionary changes that occurred during the span of Phacops' existence.
- Analyze paleoenvironmental conditions that may have enabled the emergence of Athyris, including changes in sea levels, climate, and ecological niches.