Post-Pleistocene demographic history of the North Atlantic endemic Irish moss Chondrus crispus: glacial survival, spatial expansion and gene flow

Abstract

Range expansions and gene flow as micro‐evolutionary processes played a leading role in the population demographic history of marine organisms. Herein, we sequenced partial mtDNA Cox1 gene from 26 assigned geographical populations to understand how Irish moss (Chondrus crispus) responded to severe climatic oscillations during the Pleistocene glaciations and contemporary forces such as gene flow. Phylogeographic patterns indicated that haplotype frequency distributions were strongly skewed, with nearly half found only in single samples and thus restricted to a single population. Analysis of molecular variance revealed that most of the variation was within populations with no significant genetic structuring on either side of the Atlantic. Demographic analyses indicated that ISI (Irish Sea and Ireland) and NS (the North Sea) areas experienced a slight trend of increase in population size over time, whereas EC (the English Channel) area experienced expansion beginning approximately 170 000–360 000 BP. The observed complex genetic pattern of C. crispus is consistent with a scenario of multiple unrelated founding events by survival of this species in at least three putative Pleistocene refugia along the European coastline, and subsequent trans‐Atlantic dispersal combined with contiguous northward population expansion predating the LGM and geographically gene flow.

Phylogeographic structure and deep lineage diversification of the red alga Chondrus ocellatus Holmes in the Northwest Pacific

“…Mutation rates for mtDNA Cox 1 (3.5 × 10 −9 substitutions per site per year, ss −1 year −1 ) and nrDNA ITS2 (3.0 × 10 −9 ss −1 year −1 ), based on phylogeographic estimates for the North Atlantic congener C. crispus (Hu et al . , ), were used to measure the approximate divergence times between genetic lineages.…”

Phylogeography of the bivalve Tegillarca granosa in coastal China: implications for management and conservation

“…For the redlip mullet Chelon haematocheilus, gene flow propelled by the currents between the ECS and SCS was limited, despite this species' relative long pelagic larvae stage duration (PLD) of 4 wk (Liu et al 2007). Accumulated evidence suggests that the present genetic structuring in the marine realm is more likely a product of complex species-specific ecological processes than of oceanographic circulation patterns (Hu et al 2011). From this point of view, hypotheses proposed for explaining the evolutionary history of 1 species may not be readily applicable to another, even when the 2 species have the same dispersal capacity (Marko 2004).…”

“…From this point of view, hypotheses proposed for explaining the evolutionary history of 1 species may not be readily applicable to another, even when the 2 species have the same dispersal capacity (Marko 2004). Therefore, more phylogeographical and/or biogeographical studies are needed for a comprehensive understanding of the interactive effects of various historical and present-day factors on the genetic structures of marine organisms in East Asia (Xiao et al 2010, Hu et al 2011.…”

Differences in dehydration tolerance among populations of a gametophyte‐only fern

“…Historical shifts in Earth's climate have affected the contemporary distributions of many plant species (e.g., Davis and Shaw, 2001). During periods of glaciation in the Northern Hemisphere, many species responded by retreating to lower latitudes or into protected refugia (Knowles, 2001; Trewick et al, 2002; Schonswetter et al, 2005; Hu et al, 2011). For species that retreated into refugia, the historical climatic and environmental conditions associated with these glacial periods have left lasting imprints that are discernable among contemporary populations (Normand et al, 2011; Bystriakova et al, 2014; Stevens and Emery, 2015).…”