Niche conservatism promotes speciation in cycads: the case of Dioon merolae (Zamiaceae) in Mexico
- 11 May 2020
- journal article
- research article
- Published by Wiley in New Phytologist
- Vol. 227 (6), 1872-1884
- https://doi.org/10.1111/nph.16647
Abstract
Niche conservatism is the tendency of lineages to retain the same niche as their ancestors. It constrains biological groups and prevents ecological divergence. However, theory predicts that niche conservatism can hinder gene flow, strengthen drift and increase local adaptation: does it mean that it also can facilitate speciation? Why does this happen? We aim to answer these questions. We examined the variation of chloroplast DNA, genome-wide single nucleotide polymorphisms, morphological traits and environmental variables across the Dioon merolae cycad populations. We tested geographical structure, scenarios of demographic history, and niche conservatism between population groups. Lineage divergence is associated with the presence of a geographical barrier consisting of unsuitable habitats for cycads. There is a clear genetic and morphological distinction between the geographical groups, suggesting allopatric divergence. However, even in contrasting available environmental conditions, groups retain their ancestral niche, supporting niche conservatism. Niche conservatism is a process that can promote speciation. In D. merolae, lineage divergence occurred because unsuitable habitats represented a barrier against gene flow, incurring populations to experience isolated demographic histories and disparate environmental conditions. This study explains why cycads, despite their ancient lineage origin and biological stasis, have been able to diversify into modern ecosystems worldwide.Keywords
Funding Information
- Japan Society for the Promotion of Science (18F18076)
This publication has 72 references indexed in Scilit:
- Comparative Phylogeographic Analyses Illustrate the Complex Evolutionary History of Threatened Cloud Forests of Northern MesoamericaPLOS ONE, 2013
- STRUCTURE HARVESTER: a website and program for visualizing STRUCTURE output and implementing the Evanno methodConservation Genetics Resources, 2011
- CALIBRATING DIVERGENCE TIMES ON SPECIES TREES VERSUS GENE TREES: IMPLICATIONS FOR SPECIATION HISTORY OF APHELOCOMA JAYSEvolution, 2010
- DOES NICHE DIVERGENCE ACCOMPANY ALLOPATRIC DIVERGENCE INAPHELOCOMAJAYS AS PREDICTED UNDER ECOLOGICAL SPECIATION?: INSIGHTS FROM TESTS WITH NICHE MODELSEvolution, 2009
- A Genome-Scan Method to Identify Selected Loci Appropriate for Both Dominant and Codominant Markers: A Bayesian PerspectiveGenetics, 2008
- A New Bayesian Method to Identify the Environmental Factors That Influence Recent MigrationGenetics, 2008
- formatomatic: a program for converting diploid allelic data between common formats for population genetic analysisMolecular Ecology Notes, 2007
- At‐sea distribution and scale‐dependent foraging behaviour of petrels and albatrosses: a comparative studyJournal of Animal Ecology, 2006
- Detecting the number of clusters of individuals using the software structure: a simulation studyMolecular Ecology, 2005
- Neotectonic evolution of the Isthmus of Tehuantepec (southeastern Mexico)Tectonophysics, 1998