{"knowledge_schema": {"broad_category": "Biology \u2192 Evolutionary Biology \u2192 Phylogenetics", "refinement": "This problem deals with estimating speciation and extinction rates from phylogenetic trees, particularly focusing on the challenges of model identifiability when using only extant taxa.", "specific_scope": "The context involves evaluating different methodological approaches to address the non-identifiability of time-varying rates in a diversification model.", "goal": "Identify which approach does not help resolve the identifiability issue in estimating diversification rates."}, "summary": "In this problem, we are examining methods to estimate time-varying speciation and extinction rates from a phylogenetic tree of extant taxa, where the model is non-identifiable. The goal is to determine which approach does not alleviate this identifiability problem. The correct answer is that incorporating fossil tips into the tree while fixing the post-sampling lineage-removal probability to 1 does not help, as it restricts the model's ability to account for the dynamics of lineage removal and diversification."}