Morphological and niche divergence of pinyon pines.

Alejandra Ortiz-Medrano,Daniel Patrick Scantlebury,Daniel Piñero,Alicia Mastretta-Yanes,Alejandra Vázquez-Lobo

doi:10.1002/ece3.1994

Abstract

The environmental variables that define a species ecological niche should be associated with the evolutionary patterns present in the adaptations that resulted from living in these conditions. Thus, when comparing across species, we can expect to find an association between phylogenetically independent phenotypic characters and ecological niche evolution. Few studies have evaluated how organismal phenotypes might mirror patterns of niche evolution if these phenotypes reflect adaptations. Doing so could contribute on the understanding of the origin and maintenance of phenotypic diversity observed in nature. Here, we show the pattern of niche evolution of the pinyon pine lineage (Pinus subsection Cembroides); then, we suggest morphological adaptations possibly related to niche divergence, and finally, we test for correlation between ecological niche and morphology. We demonstrate that niche divergence is the general pattern within the clade and that it is positively correlated with adaptation.

Highlights

Phenotypic features of organisms that enable them to survive in diverse environments have long fascinated evolutionary biologists who have sought to identify characters shaped by natural selection that increase the individual fitness in specific environments
We first describe the niche evolution pattern within the North American pinyon pines lineage (Pinus subsection Cembroides); based on a comparative method approach, we suggest morphological adaptations possibly related to niche divergence, and we test for niche and morphological correlation
For ecological and morphological datasets, the majority of posterior trees favoured the white noise model. We interpret that these results indicate that our data are not displaying evidence of phylogenetic dependence, so we tested for adaptation without assuming the influence of phylogeny on covariance patterns among pine species (Butler and King 2004)

Summary

Introduction

Phenotypic features of organisms that enable them to survive in diverse environments have long fascinated evolutionary biologists who have sought to identify characters shaped by natural selection that increase the individual fitness in specific environments. These adaptations, being the result of selective pressures over phenotypes, often come in the form of morphological changes that reflect the habitat or environment in which species thrive. The ecological niche understood as environmental variables and conditions that define ecological properties of species (Grinellian niche sensu Soberon 2007; Peterson 2011) should reflect the evolutionary pattern seen in the adaptations that have resulted from these same variables.

Methods

Results

Conclusion