Correct Option
Both Statement 1 and Statement 2 are incorrect.
Incorrect Options
Statement 1: The passage indicates that mussels (Mytilus californianus) become the dominant competitor and crowd out other species specifically in the absence of keystone species like the sea star Pisaster ochraceus. The study cited demonstrates that when sea stars were removed, Mytilus eventually occupied the entire substratum. This suggests that their dominance is conditional upon the absence of their predator, rather than being a general characteristic across all intertidal ecosystems.
Statement 2: The passage primarily describes the ecological role of sea stars as a keystone species, highlighting their influence on mussel populations and overall species richness within intertidal ecosystems. It details how sea stars consume mussels, thereby creating space for other species and preventing mussels from monopolizing the substratum. The passage does not provide any information regarding the factors that determine the survival of sea stars or suggest that their survival is dependent on the abundance of mussels. The focus is on the impact of sea stars on the ecosystem, not the reverse.