{"knowledge_schema": {"broad_category": "Biological Modeling \u2192 Phylogenetics \u2192 Birth-Death Models", "refinement": "This problem involves addressing the identifiability issues in statistical models used to estimate speciation and extinction rates over time in phylogenetic studies.", "specific_scope": "The focus is on identifying which strategies can effectively mitigate the identifiability issues when fitting a birth-death model with time-varying rates on a phylogeny of extant species.", "goal": "Determine which strategy does NOT help in resolving the identifiability issue in the context of the birth-death model."}, "summary": "This problem revolves around fitting a birth-death model to a phylogeny while addressing the challenge of identifiability in the model parameters. The task is to evaluate various strategies to identify which one does not contribute to resolving the identifiability issue. The strategies include using constant pieces, Bayesian frameworks, polynomial definitions, and incorporating fossil data, among others. The goal is to pinpoint the approach that fails to mitigate the identifiability problem effectively."}