Interpretation of the results of common principal components analyses |
| |
Authors: | Houle David Mezey Jason Galpern Paul |
| |
Affiliation: | Department of Zoology, University of Toronto, Toronto, ON M5S 3G5, Canada;Department of Biological Science, Florida State University, Tallahassee, Florida 32306-1100 |
| |
Abstract: | Common principal components (CPC) analysis is a new tool for the comparison of phenotypic and genetic variance-covariance matrices. CPC was developed as a method of data summarization, but frequently biologists would like to use the method to detect analogous patterns of trait correlation in multiple populations or species. To investigate the properties of CPC, we simulated data that reflect a set of causal factors. The CPC method performs as expected from a statistical point of view, but often gives results that are contrary to biological intuition. In general, CPC tends to underestimate the degree of structure that matrices share. Differences of trait variances and covariances due to a difference in a single causal factor in two otherwise identically structured datasets often cause CPC to declare the two datasets unrelated. Conversely, CPC could identify datasets as having the same structure when causal factors are different. Reordering of vectors before analysis can aid in the detection of patterns. We urge caution in the biological interpretation of CPC analysis results. |
| |
Keywords: | Common principal components analysis Flury hierarchy matrix comparisons variance-covariance matrix |
本文献已被 PubMed 等数据库收录! |
|