differentials: Estimate phenotypic selection differentials

In MorphoFun/psa: Phenotypic Selection Analysis tools

Description

differentials allows the user to evaluate how different methods for calculating phenotypic section differentials influence the output and, thus, the interpretation of indirect selection on phenotypic traits.

Usage

differentials(w, z, method = c(1,2,3,4, "all"), standardize = TRUE, ...)

Arguments

w	Relative fitness.
z	Phenotypic trait(s). Character values are not accepted.
method:	method to estimate the selection differential. 1 = covariance of relative fitness to the trait; 2 = differences in mean, variance, and covariance before and after selection; 3 = matrix algebra approach of phenotypic distributions before and after selection; 4 = ordinary least-squares regression of relative fitness against the trait; "all" = use all of the methods to produce multiple estimates.
standardize	Indicate whether phenotypic trait data should be standardized to a mean of zero and unit variance.

Value

differentials returns a data.frame

Output

dCov is the selection differential calculated from the covariance between the relative fitness, w, and each phenotypic trait z (Lande and Arnold 1983).

dBeforeAfter is the selection differential calculated as as described in Brodie et al. (1995).

dMatrix is the selection differential calculated using matrix algebra (e.g., equation 13b in Lande and Arnold (1983))

dReg is the selection differential calculated as the partial regression coefficient of relative fitness, w, against each individual phenotypic trait through univariate linear regressions.

dCovScale calculates the selection differential using the equation in dCovScale, but uses z data that are standardized to a mean of zero and unit variance.

References

Brodie III ED, Moore AJ, Janzen FJ. 1995. Visualizing and quantifying natural selection. Trends in Ecology and Evolution 10(8): 313-318. http://www.sciencedirect.com/science/article/pii/S016953470089117X

Lande R, Arnold SJ. 1983. The measurement of selection on correlated characters. Evolution 37(6): 1210-1226. http://www.jstor.org/stable/2408842

Examples

data(BumpusMales)

differentials(BumpusMales$w, BumpusMales[,3:11], "all")

MorphoFun/psa documentation built on Nov. 10, 2021, 7:01 a.m.