Wolf in sheep's clothing: Model misspecification undermines tests of the neutral theory for life histories.

Autor: Authier M; Observatoire PELAGIS UMS-CNRS 3462 Université de la Rochelle La Rochelle France., Aubry LM; Wildland Resources Department & the Ecology Center Utah State University Logan UT USA., Cam E; Laboratoire Évolution & Diversité Biologique UMR 5174 Université Toulouse III CNRS ENSFEA IRD, Toulouse Cedex 9 France.
Jazyk: angličtina
Zdroj: Ecology and evolution [Ecol Evol] 2017 Apr 04; Vol. 7 (10), pp. 3348-3361. Date of Electronic Publication: 2017 Apr 04 (Print Publication: 2017).
DOI: 10.1002/ece3.2874
Abstrakt: Understanding the processes behind change in reproductive state along life-history trajectories is a salient research program in evolutionary ecology. Two processes, state dependence and heterogeneity, can drive the dynamics of change among states. Both processes can operate simultaneously, begging the difficult question of how to tease them apart in practice. The Neutral Theory for Life Histories (NTLH) holds that the bulk of variations in life-history trajectories is due to state dependence and is hence neutral: Once previous (breeding) state is taken into account, variations are mostly random. Lifetime reproductive success (LRS), the number of descendants produced over an individual's reproductive life span, has been used to infer support for NTLH in natura. Support stemmed from accurate prediction of the population-level distribution of LRS with parameters estimated from a state dependence model. We show with Monte Carlo simulations that the current reliance of NTLH on LRS prediction in a null hypothesis framework easily leads to selecting a misspecified model, biased estimates and flawed inferences. Support for the NTLH can be spurious because of a systematic positive bias in estimated state dependence when heterogeneity is present in the data but ignored in the analysis. This bias can lead to spurious positive covariance between fitness components when there is in fact an underlying trade-off. Furthermore, neutrality implied by NTLH needs a clarification because of a probable disjunction between its common understanding by evolutionary ecologists and its translation into statistical models of life-history trajectories. Irrespective of what neutrality entails, testing hypotheses about the dynamics of change among states in life histories requires a multimodel framework because state dependence and heterogeneity can easily be mistaken for each other.
Databáze: MEDLINE