Affiliation:
1. Departamento de Ecología Evolutiva, Instituto de Ecología Universidad Nacional Autónoma de México AP70‐275 CDMX 04510 México
2. Departamento de Botánica, Instituto de Biología Universidad Nacional Autónoma de México AP 70‐233 CDMX 04510 México
3. Laboratorio de Bioconservación y Manejo, Departamento de Zoología Escuela Nacional de Ciencias Biológicas del Instituto Politécnico Nacional CDMX México
Abstract
AbstractInterspecific trait divergence may reflect adaptation and reproductive isolation, particularly after the rapid differentiation that may follow the colonization of new environments. Although new lineages are generally expected to be morphologically and ecologically similar to their ancestors, environmental forces can also drive adaptive differentiation along specific phenotypic axes. We used climate niche models and comparative analyses based on a previously inferred phylogeny to examine the history of ecological and morphological divergence of Neotropical firs (AbiesMill., Pinaceae), a group of conifers that have recently colonized and diversified in the mountains of Mexico and northern Central America. We inferred past secondary contact zones by comparing current and past climate niche projections and looked for evidence of recent interspecific gene flow using genomic data. Neotropical firs have similar niches to each other and show a strong phylogenetic signal for most evaluated morphological traits. Analyses based on individual variables suggested a random walk model of differentiation. However, early adaptation to tropical conditions is inferred in the ancestor of the southernmost firs, as all modern southern taxa are differentiated climatically fromAbies concolor, the northernmost species. In addition, observed autapomorphic traits for soil properties and the number of resin ducts in needles are consistent with possible species‐specific adaptations. Thus, a combination of nonadaptive and adaptive processes along different phenotypic axes, some related to the environment, likely operated after the southward migration of this plant lineage from North America and its subsequent radiation in the Neotropics.
Funder
Consejo Nacional de Ciencia y Tecnología
Dirección General de Asuntos del Personal Académico, Universidad Nacional Autónoma de México
Subject
Plant Science,Ecology, Evolution, Behavior and Systematics