stasis: simulate phenotypic stasis

In StratPal: Stratigraphic Paleobiology Modeling Pipelines

simulate phenotypic stasis

Description

Simulates stasis of mean trait values as independent, normally distributed random variables with mean mean and standard deviation sd

Usage

stasis(t, mean = 0, sd = 1)

Arguments

t	times at which the traits are determined
mean	number, mean trait value
sd	strictly positive number, standard deviation of traits

Value

A list with two elements: t and y. t is a duplicate of the input t, y are the corresponding trait values. Output list is of S3 class timelist (inherits from list) and can thus be plotted directly using plot, see ?admtools::plot.timelist

See Also

• random_walk() and ornstein_uhlenbeck() to simulate other modes of evolution

• stasis_sl() to simulate stasis on specimen level - for usage in conjunction with the paleoTS package.

Examples

 library("admtools") # required for plotting of results
 t = seq(0, 1, by = 0.01)
 l = stasis(t)
 plot(l, type = "l") # plot lineage
 l2 = stasis(t, mean = 0.5, sd = 0.3) # simulate second lineage
 lines(l2$t, l2$y, col = "red") # plot second lineage

StratPal documentation built on Dec. 6, 2025, 5:08 p.m.