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. Author manuscript; available in PMC: 2009 Apr 28.
Published in final edited form as: Evolution. 2008 Jul;62(7):1764–1776. doi: 10.1111/j.1558-5646.2008.00392.x

Table 2.

PGLS analysis to estimate the phylogenetic signal, lambda (λ), of each sleep trait (TST is total sleep time).

Log-likelihood for λ = 0 Log-likelihood for λ = ML Likelihood-ratio test P ML λ Lower CI of ML λ
TST −179.76 −167.42 12.34 < 0.001 1.00 0.83
NREM −156.83 −149.07 7.77 < 0.001 0.861 0.46–1.00
REM −66.08 −52.79 13.29 < 0.001 1.00 0.90

The first two columns give the Log-likelihood values for a model with λ = 0 (species independence) and for a model with λ equal to the estimate from Continuous with the highest likelihood score (ML, maximum likelihood). The third and forth columns give the likelihood-ratio test and its associated P-value. The last columns indicate the estimated ML λ value for the sleep traits and its associated lower confidence interval (when ML λ equal 1, no upper CI can be reported).

1

The ML λ value for NREM is not significantly different from 1 (P = 0.183).