[R-sig-eco] Probabilistic maturation reaction norms

[Marc Taylor]

So, it seems that there is a quite a difference between PMRNs and Maturity
ogives (see Barot et al 2004).

After searching high and low, I finally found a good description in
Dieckmann & Heino (2007) (section "Are maturation ogives and PMRNs
interchangeable?"). They state, "Maturity (described by maturity ogives) is
to maturation (described by PMRNs) what size is to growth ... For
maturation, an analogous calculation scheme for transforming from ogives to
PMRNs exists; however, this turns out to be a bit more complicated, and in
general requires additional information on growth and mortality (Barot et
al. 2004)."

Sorry to anyone that invested time in answering this question.

Cheers, Marc

###
References:
Barot, S., Heino, M., O’Brien, L., & Dieckmann, U. (2004). Estimating
reaction norms for age and size at maturation when age at first. *Evolutionary
Ecology Research*, *6*(5), 659-678.
Dieckmann, U., & Heino, M. (2007). Probabilistic maturation reaction norms:
their history, strengths, and limitations. *Marine Ecology Progress Series*,
*335*, 253-270.



On Thu, Aug 17, 2017 at 5:07 PM, Marc Taylor <marchtaylor at gmail.com> wrote:

> I'm having some difficulty getting my head around the concept of
> 'Probabilistic maturation reaction norms' (PMRN) () - as are often used to
> describe maturation schedules. These models generally describe when a
> certain species becomes mature (e.g. as a function of size and age).
>
> My issue is not in fitting such a model in R to data (e.g. fit <- glm(mat
> ~ size + age, family = binomial(link = "logit")) ). Rather, I wonder how
> such a model can be used in simulating a maturity event in an iterative
> growth model (say for a given individual). The above model can predict the
> "probability of *being *mature" at a given size and age, but what I am
> more interested for my simulation model is the "probability of *becoming *mature"
> at a given size and age, and during a given period of time. These two
> points of view do not mean the same thing in my opinion, but it looks as if
> they may be used interchangeably in the literature. It would seem that the
> latter perspective involves use of the model's derivative in some way.
>
> I would be interested if anyone has any thoughts on how such a model could
> be correctly applied in a model that simulates a change in maturity for a
> given individual.
>
> If this seems like a question more appropriate to r-sig-dynamic-models, I
> could also ask there.
>
> Cheers, Marc
>
>
>
>

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