tsd: Estimate the parameters that best describe temperature-dependent sex determination

Description

Estimate the parameters that best describe the thermal reaction norm for sex ratio when temperature-dependent sex determination occurs. It can be used also to evaluate the relationship between incubation duration and sex ratio. The parameter l was defined in Girondot (1999). The TRT is defined from the difference between the two boundary temperatures giving sex ratios of $l$ and $1 - l$, respectively: For logistic model (Girondot, 1999), it follows $$TRT_{l}=abs\left ( S\: K_{l} \right )$$ where $K_{l}$ is a constant equal to $2\: log\left ( \frac{l}{1-l} \right )$. In Girondot (1999), l was 0.05 and then the TRT was defined as being the range of temperatures producing from 5% to 95% of each sex. For other models, TRT is calculated numerically. The basic model is logistic one. This model has the particularity to have a symmetric shape around P. The other models have been built to alleviate this constraint. Hill and A-logistic models can be asymmetric, but it is impossible to control independently the low and high transitions. Hulin model is assymmetric but the control of asymmetry is difficult to manage./cr If asymmetric model is selected, it is always better to use flexit model. $$if dose < P then (1 + (2^K1 - 1) * exp(4 * S1 * (P - x)))^(-1/K1)$$ $$if dose > P then 1-((1 + (2^K2 - 1) * exp(4 * S2 * (x - P)))^(-1/K2)$$ with: $$S1 = S/((4/K1)*(2^(-K1))^(1/K1+1)*(2^K1-1))$$ $$S2 = S/((4/K2)*(2^(-K2))^(1/K2+1)*(2^K2-1))$$

Usage

tsd(
  df = NULL,
  males = NULL,
  females = NULL,
  N = NULL,
  temperatures = NULL,
  durations = NULL,
  l = 0.05,
  parameters.initial = c(P = NA, S = -2, K = 0, K1 = 1, K2 = 0),
  males.freq = TRUE,
  fixed.parameters = NULL,
  equation = "logistic",
  replicate.CI = 10000,
  range.CI = 0.95,
  replicate.NullDeviance = 1000,
  control = list(maxit = 1000),
  print = TRUE
)

Arguments

A dataframe with at least two columns named males, females or N and temperatures, Incubation.temperature or durations column

males

A vector with male numbers

females

A vector with female numbers

A vector with total numbers

temperatures

The constant incubation temperatures used to fit sex ratio

durations

The duration of incubation or TSP used to fit sex ratio

Sex ratio limits to define TRT are l and 1-l (see Girondot, 1999)

parameters.initial

Initial values for P, S or K search as a vector, ex. c(P=29, S=-0.3)

males.freq

If TRUE data are shown as males frequency

fixed.parameters

Parameters that will not be changed

equation

Could be "logistic", "Hill", "A-logistic", "Hulin", "Double-A-logistic", "flexit" or "GSD"

replicate.CI

Number of replicates to estimate confidence intervals

range.CI

The range of confidence interval for estimation, default=0.95

replicate.NullDeviance

Number of replicates to estimate null distribution of deviance

control

List of parameters used in optim.

Should the results be printed at screen? TRUE (default) or FALSE

Value

A list the pivotal temperature, transitional range of temperatures and their SE

Details

tsd estimates the parameters that best describe temperature-dependent sex determination

References

Girondot, M. 1999. Statistical description of temperature-dependent sex determination using maximum likelihood. Evolutionary Ecology Research, 1, 479-486.

Godfrey, M.H., Delmas, V., Girondot, M., 2003. Assessment of patterns of temperature-dependent sex determination using maximum likelihood model selection. Ecoscience 10, 265-272.

Hulin, V., Delmas, V., Girondot, M., Godfrey, M.H., Guillon, J.-M., 2009. Temperature-dependent sex determination and global change: are some species at greater risk? Oecologia 160, 493-506.

Examples

Run this code

# NOT RUN {
library(embryogrowth)
CC_AtlanticSW <- subset(DatabaseTSD, RMU=="Atlantic, SW" & 
                          Species=="Caretta caretta" & (!is.na(Sexed) & Sexed!=0) &
                          !is.na(Correction.factor))
tsdL <- with (CC_AtlanticSW, tsd(males=Males, females=Females, 
                                 temperatures=Incubation.temperature-Correction.factor, 
                                 equation="logistic", replicate.CI=NULL))
tsdH <- with (CC_AtlanticSW, tsd(males=Males, females=Females, 
                                 temperatures=Incubation.temperature-Correction.factor, 
                                 equation="Hill", replicate.CI=NULL))
tsdR <- with (CC_AtlanticSW, tsd(males=Males, females=Females, 
                                 temperatures=Incubation.temperature-Correction.factor, 
                                 equation="A-logistic", replicate.CI=NULL))
tsdF <- with (CC_AtlanticSW, tsd(males=Males, females=Females, 
                                 temperatures=Incubation.temperature-Correction.factor, 
                                 equation="Flexit", replicate.CI=NULL))
tsdDR <- with (CC_AtlanticSW, tsd(males=Males, females=Females, 
                                 temperatures=Incubation.temperature-Correction.factor, 
                                 equation="Double-A-logistic", replicate.CI=NULL))
gsd <- with (CC_AtlanticSW, tsd(males=Males, females=Females, 
                                 temperatures=Incubation.temperature-Correction.factor, 
                                 equation="GSD", replicate.CI=NULL))
compare_AIC(Logistic_Model=tsdL, Hill_model=tsdH, Alogistic_model=tsdR, 
               flexit=tsdF, 
               DoubleAlogistic_model=tsdDR, GSD_model=gsd)
compare_AICc(Logistic_Model=tsdL, Hill_model=tsdH, Alogistic_model=tsdR, 
               DoubleAlogistic_model=tsdDR, GSD_model=gsd, factor.value = -1)
compare_BIC(Logistic_Model=tsdL, Hill_model=tsdH, Alogistic_model=tsdR, 
               DoubleAlogistic_model=tsdDR, GSD_model=gsd, factor.value = -1)
##############
eo <- subset(DatabaseTSD, Species=="Emys orbicularis", c("Males", "Females", 
                                       "Incubation.temperature"))
                                       
eo_Hill <- with(eo, tsd(males=Males, females=Females, 
                                       temperatures=Incubation.temperature,
                                       equation="Hill"))
eo_Hill <- tsd(df=eo, equation="Hill", replicate.CI=NULL)
eo_logistic <- tsd(eo, replicate.CI=NULL)
eo_Alogistic <- with(eo, tsd(males=Males, females=Females, 
                                 temperatures=Incubation.temperature, 
                                 equation="a-logistic", replicate.CI=NULL))
### The Hulin model is a modification of A-logistic (See Hulin et al. 2009)

########## Caution
### It should not be used anymore as it can produce unexpected results
par <- eo_Alogistic$par
names(par)[which(names(par)=="K")] <- "K2"
par <- c(par, K1=0)
eo_Hulin <- with(eo, tsd(males=Males, females=Females, 
                                 parameters.initial=par, 
                                 temperatures=Incubation.temperature, 
                                 equation="Hulin", replicate.CI=NULL))
                                 
### The Double-A-logistic model is a A-logistic model with K1 and K2 using respectively
### below and above P

########## Caution
### The curve is not smooth at pivotal temperature

par <- eo_Alogistic$par
names(par)[which(names(par)=="K")] <- "K2"
par <- c(par, K1=as.numeric(par["K2"])*0.8)
par["K2"] <- par["K2"]*0.8
eo_Double_Alogistic <- with(eo, tsd(males=Males, females=Females,
                                 parameters.initial=par,
                                 temperatures=Incubation.temperature,
                                 equation="Double-a-logistic", replicate.CI=NULL))
                                 
### The flexit model is modeled with K1 and K2 using respectively
### below and above P and smooth transition at P; S is the slope at P

par <- c(eo_logistic$par["P"], 1/4*eo_logistic$par["S"], K1=1, K2=1)
eo_flexit <- with(eo, tsd(males=Males, females=Females,
                                 parameters.initial=par,
                                 temperatures=Incubation.temperature,
                                 equation="flexit", replicate.CI=NULL))
                                 
compare_AIC(Logistic=eo_logistic, Hill=eo_Hill, Alogistic=eo_Alogistic, 
             Hulin=eo_Hulin, Double_Alogistic=eo_Double_Alogistic, 
             flexit=eo_flexit)
## Note that SE for lower limit of TRT is wrong
plot(eo_flexit)
## To get correct confidence interval, check \code{tsd_MHmcmc()}. 
             
### Note the asymmetry of the Double-A-logistic and flexit models
predict(eo_Double_Alogistic, 
       temperatures=c(eo_Double_Alogistic$par["P"]-0.2, eo_Double_Alogistic$par["P"]+0.2))
predict(eo_Double_Alogistic)

(p <- predict(eo_flexit, 
       temperatures=c(eo_flexit$par["P"]-0.3, eo_flexit$par["P"]+0.3)))
p["50%", 1]-0.5; 0.5-p["50%", 2]
predict(eo_flexit)

### It can be used also for incubation duration
CC_AtlanticSW <- subset(DatabaseTSD, RMU=="Atlantic, SW" & 
                          Species=="Caretta caretta" & Sexed!=0)
tsdL_IP <- with (CC_AtlanticSW, tsd(males=Males, females=Females, 
                                 durations=IP.mean, 
                                 equation="logistic", replicate.CI=NULL))
plot(tsdL_IP, xlab="Incubation durations in days")
# Example with Chelonia mydas
cm <- subset(DatabaseTSD, Species=="Chelonia mydas" & !is.na(Sexed), c("Males", "Females", 
                                       "Incubation.temperature", "RMU"))
tsd(subset(cm, subset=RMU=="Pacific, SW"))
tsd(subset(cm, subset=RMU=="Pacific, Northwest"))
tsd(subset(cm, subset=RMU=="Atlantic, S Caribbean"))

### Eretmochelys imbricata
Ei_PacificSW <- subset(DatabaseTSD, RMU=="Pacific, SW" & 
                       Species=="Eretmochelys imbricata")
Ei_AtlanticW <- subset(DatabaseTSD, RMU=="Atlantic, W (Caribbean and E USA)" & 
                       Species=="Eretmochelys imbricata")
Ei_AtlanticSW <- subset(DatabaseTSD, RMU=="Atlantic, SW" & 
                       Species=="Eretmochelys imbricata")
Ei_PacSW <- tsd(Ei_PacificSW)
Ei_AtlW <- tsd(Ei_AtlanticW)
Ei_AtlSW <- tsd(Ei_AtlanticSW)

plot(Ei_PacSW, xlim=c(27, 33), show.PTRT = FALSE, main=expression(italic("Eretmochelys imbricata")))
par(new=TRUE)
plot(Ei_AtlW, xlim=c(27, 33), col="red", xlab="", ylab="", 
     axes=FALSE, xaxt="n", show.PTRT = FALSE, errbar.col="red")
par(new=TRUE)
plot(Ei_AtlSW, xlim=c(27, 33), col="blue", xlab="", ylab="", axes=FALSE, 
     xaxt="n", show.PTRT = FALSE, errbar.col="blue")
legend("topright", legend=c("Pacific, SW", "Atlantic, W", "Atlantic, SW"), lty=1, 
col=c("black", "red", "blue"))

### Chelonia mydas
Cm_PacificSW <- subset(DatabaseTSD, RMU=="Pacific, SW" & !is.na(Sexed) & 
                       Species=="Chelonia mydas")
Cm_PacificNW <- subset(DatabaseTSD, RMU=="Pacific, NW" &  !is.na(Sexed) & 
                       Species=="Chelonia mydas")
Cm_AtlanticSC <- subset(DatabaseTSD, RMU=="Atlantic, S Caribbean" &  !is.na(Sexed) & 
                       Species=="Chelonia mydas")
Cm_IndianSE <- subset(DatabaseTSD, RMU=="Indian, SE" &  !is.na(Sexed) & 
                       Species=="Chelonia mydas")
Cm_PacSW <- tsd(Cm_PacificSW)
Cm_PacNW <- tsd(Cm_PacificNW)
Cm_IndSE <- tsd(Cm_IndianSE)
Cm_AtlSC <- tsd(Cm_AtlanticSC)

plot(Cm_PacSW, xlim=c(24, 34), show.PTRT = FALSE, main=expression(italic("Chelonia mydas")))
par(new=TRUE)
plot(Cm_PacNW, xlim=c(24, 34), col="red", xlab="", ylab="", 
     axes=FALSE, xaxt="n", show.PTRT = FALSE, errbar.col="red")
par(new=TRUE)
plot(Cm_IndSE, xlim=c(24, 34), col="blue", xlab="", ylab="", 
     axes=FALSE, xaxt="n", show.PTRT = FALSE, errbar.col="blue")
par(new=TRUE)
plot(Cm_AtlSC, xlim=c(24, 34), col="green", xlab="", ylab="", 
     axes=FALSE, xaxt="n", show.PTRT = FALSE, errbar.col="green")

# To fit a TSDII or FMF TSD pattern, you must indicate P_low, S_low, P_high, and S_high
# for logistic model and P_low, S_low, K1_low, K2_low, P_high, S_high, K1_high, and K2_high for 
# flexit model
# The model must be 0-1 for low and 1-0 for high with P_low < P_high

Chelydra_serpentina <- subset(DatabaseTSD, !is.na(Sexed) & (Sexed != 0) & 
                       Species=="Chelydra serpentina")
                       
model_TSDII <- tsd(Chelydra_serpentina, males.freq=FALSE, 
                   parameters.initial=c(P_low=21, S_low=0.3, P_high=28, S_high=-0.4), 
                   equation="logistic")
plot(model_TSDII, lab.TRT = "TRT l = 5 %")
priors <- tsd_MHmcmc_p(result=model_TSDII, accept=TRUE)
out_mcmc <- tsd_MHmcmc(result=model_TSDII, n.iter=10000, parametersMCMC=priors)
plot(model_TSDII, resultmcmc=out_mcmc, lab.TRT = "TRT l = 5 %")
predict(model_TSDII, temperatures=25:35)

# Podocnemis expansa
Podocnemis_expansa <- subset(DatabaseTSD, !is.na(Sexed) & (Sexed != 0) & 
                       Species=="Podocnemis expansa")
Podocnemis_expansa_Valenzuela_2001 <- subset(Podocnemis_expansa, 
                   Reference=="Valenzuela, 2001")
PeL2001 <- tsd(df=Podocnemis_expansa_Valenzuela_2001)
# The pivotal temperature is 32.133 <U+00B0>C (CI 95% 31.495;32.766)
# In Valenzuela, 2001: "Using data from the present study alone, 
# the critical temperature was 32.2 <U+00B0>C by both methods and the 95% 
# confidence limits were 31.4 <U+00B0>C and 32.9 <U+00B0>C."
# Data are close but not identical to what was published.

# The pivotal temperature calculated by maximum likelihood and by inverse 
# prediction from logistic regression, was 32.6<U+00B0>C using raw data from 
# 1991 (N. Valenzuela, unpublished data) and from this study. The lower 
# and upper 95% confidence limits of the pivotal temperature were 32.2<U+00B0>C 
# and 33.2<U+00B0>C,

Podocnemis_expansa_Valenzuela_1997 <- subset(Podocnemis_expansa, 
                   subset=(((Reference=="Lance et al., 1992; Valenzuela et al., 1997") | 
                   (Reference=="Valenzuela, 2001")) & 
                   (!is.na(Sexed)) & (Sexed != 0)))

PeL1997 <- tsd(df=Podocnemis_expansa_Valenzuela_1997)

# }

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