Model Based Phylogenetic Analysis.

Installation

To install this package:

devtools::install_github("daijiang/phyr")
# or install from binary file (may not be the latest version)
# macOS
install.packages("https://raw.githubusercontent.com/daijiang/phyr/master/phyr_1.0.3.tgz", repos = NULL)
# Windows
install.packages("https://raw.githubusercontent.com/daijiang/phyr/master/phyr_0.1.6.zip", repos = NULL)

Main functions

The phyr package has three groups of functions:

1. community phylogenetic diversity metrics (alpha: psv, psr, pse, etc. and beta: pcd), which were included in the picante package originally. They were updated with c++ to improve speed.
2. models to estimate correlation between functional traits while accounting for phylogenetic relationships (cor_phylo), which was included in the ape package originally. It has new syntax, much improved performance (c++), and bootstrapping option.
3. phylogenetic generalized linear mixed models (pglmm), which was originally included in the pez package. It has new model formula syntax that allows straightforward model set up, a faster version of maximum likelihood implementation via c++, and a Bayesian model fitting framework based on INLA.
   • We hope the model formula proposed here can be used to standardize PGLMMs set up across different tools (e.g. brms for Stan).
   • PGLMM for comparative data (pglmm.compare), which was originally from ape::binaryPGLMM() but has more features.

Usage examples of pglmm()

pglmm use similar syntax as lme4::lmer to specify random terms: add __ (two underscores) at the end of grouping variable (e.g. sp) to specify both phylogenetic and non-phylogenetic random terms; use (1|sp__@site) to specify nested term (i.e. species phylogenetic matrix V_sp nested within the diagonal of site matrix I_site) to test phylogenetic overdispersion or underdispersion. This should be the most commonly used one and is equal to kronecker(I_site, V_sp).

We can also use a second phylogeny for bipartite questions. For example, (1|parasite@host__) will be converted to kronecker(V_host, I_parasite); (1|parasite__@host__) will be converted to kronecker(V_host, V_parasite).

For details about model formula, see documentation ?phyr::pglmm. More application examples can be found in Ives 2018 Chapter 4.

library(phyr)

library(dplyr)
## 
## Attaching package: 'dplyr'
## The following objects are masked from 'package:stats':
## 
##     filter, lag
## The following objects are masked from 'package:base':
## 
##     intersect, setdiff, setequal, union
comm = comm_a
comm$site = row.names(comm)
dat = tidyr::gather(comm, key = "sp", value = "freq", -site) %>% 
  left_join(envi, by = "site") %>% 
  left_join(traits, by = "sp")
dat$pa = as.numeric(dat$freq > 0)
head(dat)
##    site          sp freq  sand shade   precip       tmin sla veg.height
## 1 s3293 Acer_rubrum    0 80.75  20.9 1.902397  0.1288019 294      170.5
## 2 s3294 Acer_rubrum    3 83.36  45.1 1.902397  0.1288019 294      170.5
## 3 s3295 Acer_rubrum    8 88.83  58.9 1.922669 -0.1061756 294      170.5
## 4 s3296 Acer_rubrum    0 91.24  19.7 1.922669 -0.1061756 294      170.5
## 5 s3297 Acer_rubrum    0 90.04  56.6 1.922669 -0.1061756 294      170.5
## 6 s3299 Acer_rubrum   15 81.87  87.0 1.899665  0.1736423 294      170.5
##   disp.mode pa
## 1      Wind  0
## 2      Wind  1
## 3      Wind  1
## 4      Wind  0
## 5      Wind  0
## 6      Wind  1
# phy-LMM
test1 = phyr::pglmm(freq ~ 1 + shade + (1|sp__) + (1|site) + (1|sp__@site), 
                    data = dat, family = "gaussian", REML = FALSE,
                    cov_ranef = list(sp = phylotree))
## Warning: Drop species from the phylogeny that are not in the variable sp
test1
## Linear mixed model fit by maximum likelihood
## 
## Call:freq ~ 1 + shade
## 
## logLik    AIC    BIC 
## -463.3  940.6  956.5 
## 
## Random effects:
##              Variance   Std.Dev
## 1|sp        7.345e-01 0.8570105
## 1|sp__      1.800e-04 0.0134157
## 1|site      1.035e-07 0.0003217
## 1|sp__@site 2.138e-05 0.0046238
## residual    3.261e+00 1.8058430
## 
## Fixed effects:
##                  Value  Std.Error  Zscore   Pvalue    
## (Intercept) -0.1911039  0.3920853 -0.4874 0.625972    
## shade        0.0226917  0.0067263  3.3736 0.000742 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
# phy-GLMM
test2 = phyr::pglmm(pa ~ 1 + shade + (1|sp__) + (1|site) + (1|sp__@site), 
                    data = dat, family = "binomial", REML = FALSE,
                    cov_ranef = list(sp = phylotree))
## Warning: Drop species from the phylogeny that are not in the variable sp
test2
## Generalized linear mixed model for binomial data fit by maximum likelihood
## 
## Call:pa ~ 1 + shade
## 
## 
## Random effects:
##              Variance  Std.Dev
## 1|sp        1.786e-06 0.001336
## 1|sp__      4.441e-01 0.666389
## 1|site      4.496e-06 0.002120
## 1|sp__@site 8.689e-06 0.002948
## 
## Fixed effects:
##                  Value  Std.Error  Zscore    Pvalue    
## (Intercept) -2.0835724  0.5744500 -3.6271 0.0002867 ***
## shade        0.0165916  0.0087165  1.9035 0.0569784 .  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
# bipartite
tree_site = ape::rtree(n = n_distinct(dat$site), tip.label = sort(unique(dat$site)))
z_bipartite = phyr::pglmm(freq ~ 1 + shade + (1|sp__) + (1|site__) + 
                            (1|sp__@site) + (1|sp@site__) + (1|sp__@site__), 
                          data = dat, family = "gaussian",REML = TRUE,
                          cov_ranef = list(sp = phylotree, site = tree_site))
## Warning: Drop species from the phylogeny that are not in the variable sp
z_bipartite
## Linear mixed model fit by restricted maximum likelihood
## 
## Call:freq ~ 1 + shade
## 
## logLik    AIC    BIC 
## -466.0  952.1  974.8 
## 
## Random effects:
##                Variance  Std.Dev
## 1|sp          1.648e-02 0.128377
## 1|sp__        1.173e+00 1.082923
## 1|site        2.792e-02 0.167098
## 1|site__      8.659e-03 0.093052
## 1|sp__@site   1.965e+00 1.401671
## 1|sp@site__   7.968e-02 0.282273
## 1|sp__@site__ 8.041e-05 0.008967
## residual      9.625e-01 0.981064
## 
## Fixed effects:
##                 Value Std.Error  Zscore Pvalue
## (Intercept) -0.127328  0.815075 -0.1562 0.8759
## shade        0.019393  0.011889  1.6311 0.1029

Licenses

Licensed under the GPL-3 license.

Contributing

Contributions are welcome. You can provide comments and feedback or ask questions by filing an issue on Github here or making pull requests.

Code of conduct

Please note that the 'phyr' project is released with a Contributor Code of Conduct. By contributing to this project, you agree to abide by its terms.