CAIC

CAIC performs phylogenetically informed comparative analyses using independent contrasts to test hypotheses about trait evolution among species.

Key Features:

• Independent Contrasts: Implements the independent contrasts algorithm to partition variance among species into independent linear contrasts at nodes of a species tree.
• Phylogenetic Information: Uses phylogenetic information from the dataset's species tree to account for shared evolutionary history in statistical comparisons.
• Partitioning Procedures: Provides two partitioning procedures, one for datasets where all variables are continuous and another for datasets that include a discrete variable.
• Non-independence Correction: Accounts for non-independence among species due to common descent, addressing the failure of standard regression assumptions in comparative data.
• Correlated Evolution Testing: Enables testing hypotheses about correlated evolution among traits across species.
• Parameter Estimation: Supports estimation of parameters such as allometric exponents.
• Rate Comparisons: Allows comparison of rates of evolutionary change across species.

Scientific Applications:

• Comparative Multi-species Analysis: Analysis of comparative multi-species datasets involving continuous variables to test evolutionary hypotheses.
• Adaptation Hypothesis Testing: Testing hypotheses about organism adaptation to environments through species comparisons while accounting for phylogeny.
• Trait Correlation Studies: Assessing correlated evolution among morphological or physiological traits.
• Allometry Studies: Estimating allometric exponents to study scaling relationships among traits.
• Evolutionary Rate Analysis: Comparing rates of evolutionary change across lineages within a phylogenetic framework.

Methodology:

Computes independent linear contrasts from a species tree and partitions variance at phylogenetic nodes, with two procedures for entirely continuous datasets and for datasets that include a discrete variable.