phyloP scores measure evolutionary conservation at individual alignment sites. Interpretations of the scores are compared to the evolution that is expected under neutral drift.
Positive scores — Measure conservation, which is slower evolution than expected, at sites that are predicted to be conserved.
Negative scores — Measure acceleration, which is faster evolution than expected, at sites that are predicted to be fast-evolving.
phyloP scores are useful to evaluate the signatures of selection at particular nucleotides or classes of nucleotides. For example, as with third codon positions, or first positions of miRNA target sites.
The absolute values of phyloP scores represent –log p-values under a null hypothesis of neutral evolution.
The following range of scores is used in the Ion Reporter™ Software phyloP filter. See phyloP for an explanation of how this range is determined.
For more information on phyloP, see the following website.
To find the latest UCSC Genome Browser database search for "UCSC Genome Browser update" in the PubMed website: https://www.ncbi.nlm.nih.gov/pubmed/.