Hi Jarrod,
Thanks very much for your fast reply. Egg-laying and live-bearing are
dispersed throughout the tree ( I have attached a PDF of a traitplot with
egg-laying and live-bearing on it; blue is egg-laying and red is
live-bearing), being universal in chimaeras and skates, and found in
several families of galeomorph sharks. Here are the summaries of the two
models:

#############
>summary(dep)
Iterations = 3001:12991
 Thinning interval  = 10
 Sample size  = 1000

 DIC: 62.7561

 G-structure:  ~animal

       post.mean l-95% CI u-95% CI eff.samp
animal         1        1        1        0

 R-structure:  ~units

      post.mean l-95% CI u-95% CI eff.samp
units         1        1        1        0

 Location effects: parity ~ log.med.depth

              post.mean l-95% CI u-95% CI eff.samp pMCMC
(Intercept)     0.13854 -0.97336  1.40576    52.98  0.87
log.med.depth  -0.06105 -0.37972  0.32122    14.31  0.69

#############################
>summary(glm)
Call:
glm(formula = parity ~ log.med.depth, family = binomial(link = probit),
    data = traits)

Deviance Residuals:
    Min       1Q   Median       3Q      Max
-2.5976  -1.0564   0.5410   0.8522   1.6867

Coefficients:
              Estimate Std. Error z value Pr(>|z|)
(Intercept)     2.6195     0.2428  10.789   <2e-16 ***
log.med.depth  -0.9815     0.1030  -9.526   <2e-16 ***
---
Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1

(Dispersion parameter for binomial family taken to be 1)

    Null deviance: 784.17  on 609  degrees of freedom
Residual deviance: 683.16  on 608  degrees of freedom
AIC: 687.16

Number of Fisher Scoring iterations: 4


Please let me know if there is any more info I can provide...


Cheers,
Chris

On Thu, Dec 15, 2016 at 11:02 PM, Jarrod Hadfield <j.hadfi...@ed.ac.uk>
wrote:

> Hi Chris,
>
> I think ngen in threshbayes is not the number of full iterations (i.e. a
> full update of all parameters), but the number of full iterations
> multiplied by the number of nodes (2n-1). With n=600 species this means
> threshbayes has only really done about 8,000 iterations (i.e. about 1000X
> less than MCMCglmm). Simulations suggest threshbayes is about half as
> efficient per full iteration as MCMCglmm which means that it may have only
> collected 0.5*1132/1200 = 0.47 effective samples from the posterior. The
> very extreme value and the surprisingly tight credible intervals (+/-0.007)
> also suggest a problem.
>
> **However**, the low effective sample size for the covariance in the
> MCMglmm model is also worrying given the length of chain, and may point to
> potential problems. Are egg-laying/live-bearing scattered throughout the
> tree, or do they tend to aggregate a lot? Can you send me the output from:
>
> prior.dep<-=list(R=list(V=diag(1)*1e-15, fix=1),
> G=list(G1=list(V=diag(1), fix=1)))
>
> dep<-MCMCglmm(parity~log.med.depth,
>                        random=~animal,
>                        rcov=~units,
>                        pedigree=shark.tree,
>                        reduced=TRUE,
>                        data=traits,
>                        prior=prior2,
>                        pr=TRUE,
>                        pl=TRUE,
>                        family="threshold")
>
> summary(dep)
>
> summary(glm(parity~log.med.depth, data=traits,
> family=binomial(link=probit)))
>
> Cheers,
>
> Jarrod
>
>
>
> On 15/12/2016 20:59, Chris Mull wrote:
>
> Hi All,
> I am trying to look at the correlated evolution of traits using the
> threshold model as implemented in phytools::threshBayes (Revell 2014) and
> MCMCglmmRAM (Hadfield 2015). My understanding from Hadfield 2015 is that
> the reduced animal models should yeild equivalent results, yet having run
> both I am having trouble reconciling the results. I have a tree covering
> ~600 species of sharks. skates, and rays and am interested in testing for
> the correlated evolution between reproductive mode (egg-laying and
> live-bearing) with depth. When I test for this correlation using
> phytools:threshBayes there is a clear result with a high correlation
> coefficient (-0.986) as I would predict. When I run the same analysis using
> MCMCglmmRAM I get a very different result, with a low degree of covariation
> and CI crossing zero (-0.374; -3.638 - 3.163 95%CI). Both models are run
> for 10,000,000 generations with the same bunr-in and sampling period. I
> have looked at the trace plots for each model using coda and parameter
> estimates and likelihodd . I'm not sure how to reconcile the differences in
> these results and any advice would be greatly appreciated. I have appended
> the code and outputs below.
>
>
> #######################
> #phytools::threshBayes#
> #######################
>
> X<-shark.data[c("parity","log.med.depth")]
> X<-as.matrix(X)
>
> #mcmc paramters (also see control options)
> ngen<-10000000
> burnin<-0.2*ngen
> sample<-500
>
> thresh<-threshBayes(shark.tree,
>                    X,
>                    types=c("discrete","continuous"),
>                    ngen=ngen,
>                    control = list(sample=sample))
>
> The return correlation is -0.986 (-0.99 - -0.976  95%HPD)
>
>
> #############################
> #MCMCglmm bivariate-gaussian#
> #############################
>
>
> prior2=list(R=list(V=diag(2)*1e-15, fix=1), G=list(G1=list(V=diag(2),
>
> nu=0.002, fix=2)))
>
> ellb.log.dep<-MCMCglmm(cbind(log.med.depth,parity)~trait-1,
>                       random=~us(trait):animal,
>                       rcov=~us(trait):units,
>                       pedigree=shark.tree,
>                       reduced=TRUE,
>                       data=traits,
>                       prior=prior2,
>                       pr=TRUE,
>                       pl=TRUE,
>                       family=c("gaussian", "threshold"),
>                       thin=500,
>                       burnin = 1000000,
>                       nitt = 10000000)
>
> summary(ellb.log.dep)
>
> Iterations = 1000001:9999501
> Thinning interval  = 500
> Sample size  = 18000
> DIC: 2930.751
> G-structure:  ~us(trait):animal
>                                         post.mean l-95% CI u-95% CI eff.samp
> traitscale.depth:traitscale.depth.animal    16.965   15.092   18.864
>  18000
> traitparity:traitscale.depth.animal         -0.374   -3.638    3.163
> 1132
> traitscale.depth:traitparity.animal         -0.374   -3.638    3.163
> 1132
> traitparity:traitparity.animal               1.000    1.000    1.000
>  0
> R-structure:  ~us(trait):units
>                                        post.mean l-95% CI u-95% CI eff.samp
> traitscale.depth:traitscale.depth.units    16.965   15.092   18.864    18000
> traitparity:traitscale.depth.units         -0.374   -3.638    3.163     1132
> traitscale.depth:traitparity.units         -0.374   -3.638    3.163     1132
> traitparity:traitparity.units               1.000    1.000    1.000        0
> Location effects: cbind(scale.depth, parity) ~ trait - 1
>                 post.mean l-95% CI u-95% CI eff.samp pMCMC
> traitscale.depth   0.12297 -3.63655  4.02005    18000 0.949
> traitparity       -0.02212 -1.00727  0.93387    17058 0.971
>
> Thanks for any and all input.
>
> Cheers,
> Chris
>
>
>
>
> The University of Edinburgh is a charitable body, registered in
> Scotland, with registration number SC005336.
>
>


-- 
Christopher Mull
PhD Candidate, Shark Biology and Evolutionary Neuroecology
Dulvy Lab
Simon Fraser University
Burnaby,B.C.
V5A 1S6
Canada
(778) 782-3989
twitter: @mrsharkbrain
e-mail:cm...@sfu.ca
www.christophermull.weebly.com
www.earth2ocean.org

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