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Macroecological trend of increasing values of intraspecific genetic diversity and population structure from temperate to tropical streams
Author(s) -
SalinasIvanenko Sofia,
Múrria Cesc
Publication year - 2021
Publication title -
global ecology and biogeography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.164
H-Index - 152
eISSN - 1466-8238
pISSN - 1466-822X
DOI - 10.1111/geb.13344
Subject(s) - biological dispersal , ecology , biology , coalescent theory , intraspecific competition , genetic structure , population , genetic diversity , macroecology , biodiversity , phylogenetic tree , biochemistry , demography , sociology , gene
Aim Assuming genetic variants are selectively neutral, estimates of intraspecific genetic diversity and population structure should increase simultaneously in parallel to coalescent time, population size and gene flow. However, other processes, such as genetic drift associated with demographic fluctuations, might cause a loss of genetic diversity while not affecting population structure. In this study, we assess large‐scale patterns of estimates of intraspecific genetic variation across species to determine the roles of dispersal, biogeography, divergence time and demographic fluctuations in decoupling genetic diversity and population structure. Location Pristine first‐order streams distributed in seven regions from Neotropical to boreal climate, covering a gradient of habitat persistence through major biogeographical changes (e.g., Pleistocene glaciations). Time period 2008–2010. Major taxa studied Freshwater insect lineages that differ in dispersal propensity. Methods Intraspecific nucleotide diversity (π) and population structure (Φ ST ) were estimated for 33 species using 2,128 sequences of the cox1 gene. The correlation between π and Φ ST was tested using linear regression models. The geographical distribution of haplotypes was represented in networks. Phylogenetic trees were time calibrated to determine divergence time. Results At a global scale, a positive relationship between π and Φ ST was found. Neotropical species showed the highest values of π and Φ ST , probably owing to historical environmental stability. Across Europe, the low estimates of π and the wide array of Φ ST values and haplotype networks found across species, lineages and latitude were contrary to the biogeographical and dispersal paradigms. Main conclusions Beyond the macroecological trend found, genetic trajectories of co‐distributed temperate species were disassociated from their functional traits and probably caused by persistent demographic fluctuations associated with local‐scale habitat instability. Overall, the idiosyncratic relationship between π and Φ ST across species prevents the establishment of conclusive global patterns and questions the phylogeographical patterns established when studying a reduced number of co‐distributed species.