Assess concordance of δ statistic and RERconverge for multi-state traits with many transitions

Ascertain whether the δ statistic and RERconverge identify overlapping sets of genetic elements when applied to non-binary categorical traits that have many ancestral transitions, and characterize the conditions under which agreement or divergence between the two approaches occurs.

Background

RERconverge detects correlations between relative evolutionary rates and trait categories, while the δ statistic evaluates phylogenetic signal in categorical traits on gene trees.

Prior work reported substantial agreement between the two approaches for binary traits with few transitions. The extent to which this concordance holds for multi-state traits with many transitions remains unresolved.

References

It has previously been found that these two approaches tend to identify the same genetic elements for a binary trait with few transitions in phenotype \citep{Kowalczyk2022}, but it is not yet clear if the same will be true for non-binary categorical traits with many ancestral transitions in phenotype \citep{Treaster2021}.

— From trees to traits: A review of advances in PhyloG2P methods and future directions  (2501.07043 - Macdonald et al., 13 Jan 2025) in Subsection 'Defining and measuring traits to produce meaningful genotype to phenotype maps' (Additional considerations)