title: Linear-In-The-Parameters Oblique Least Squares (LOLS) Provides More Accurate Estimates of Density-Dependent Survival.
abstract: Survival is a fundamental demographic component and the importance of its accurate estimation goes beyond the traditional estimation of life expectancy. The evolutionary stability of isomorphic biphasic life-cycles and the occurrence of its different ploidy phases at uneven abundances are hypothesized to be driven by differences in survival rates between haploids and diploids. We monitored Gracilaria chilensis, a commercially exploited red alga with an isomorphic biphasic life-cycle, having found density-dependent survival with competition and Allee effects. While estimating the linear-in-the-parameters survival function, all model I regression methods (i.e, vertical least squares) provided biased line-fits rendering them inappropriate for studies about ecology, evolution or population management. Hence, we developed an iterative two-step non-linear model II regression (i.e, oblique least squares), which provided improved line-fits and estimates of survival function parameters, while robust to the data aspects that usually turn the regression methods numerically unstable.
authors.affiliation: MARETEC, Instituto Superior Técnico, Universidade Técnica de Lisboa, Av. Rovisco Pais, Lisboa, Portugal.
authors.forename: Vasco M N C S
authors.initials: VM
authors.lastname: Vieira
authors.affiliation: CCMAR, Center of Marine Science,-CIMAR Laboratorio Associado, F.C.T., University of Algarve, Campus Gambelas, Faro, Portugal.
authors.forename: Aschwin H
authors.initials: AH
authors.lastname: Engelen
authors.affiliation: Instituto de Ciencias Ambientales y Evolutivas, Facultad de Ciencias, Universidad Austral de Chile, Casilla, Valdivia, Chile.
authors.forename: Oscar R
authors.initials: OR
authors.lastname: Huanel
authors.affiliation: Instituto de Ciencias Ambientales y Evolutivas, Facultad de Ciencias, Universidad Austral de Chile, Casilla, Valdivia, Chile.|CNRS, Sorbonne Universités, UPMC University Paris VI, UMI 3614, Evolutionary Biology and Ecology of Algae, Station Biologique de Roscoff, CS, Place G. Tessier, Roscoff, France.
authors.forename: Marie-Laure
authors.initials: ML
authors.lastname: Guillemin
mesh_terms: D000465:Algorithms; D005075:Biological Evolution; D004171:Diploidy; D006238:Haploidy; D006801:Humans; D016018:Least-Squares Analysis; D008018:Life Cycle Stages; D016013:Likelihood Functions; D008954:Models, Biological; D011156:Population Density; D000461:Rhodophyta / Q000235:genetics / Q000254:growth & development* / Q000502:physiology