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Biology subjects

von der Heyden, S.

Publications and source records attributed to von der Heyden, S..

2 recordsLinked to original sources

Applying genomic data to seagrass conservation

Although genomic diversity is increasingly recognised as a key component of biodiversity, it is seldom used to inform conservation planning. Estuaries and keystone species such as the southern African seagrass, Zostera capensis, are under severe anthropogenic pressure and are often poorly protected. In this study we integrated SNP data generated from populations of Z. capensis across the South African coastline into the spatial prioritisation tool Marxan. We included different measures of genomic variation to account for genomic diversity, distinctness and evolutionary potential to explore spatial planning scenarios. We investigated how conservation priority areas identified by targeting only habitat type, differed from those identified by also including genomic measures; further we assessed how different genetic diversity metrics change prioritisation outcomes. All scenarios targeting genomic variation identified unique conservation prioritisation areas compared to scenarios only targeting habitat type. As such, omitting these estuaries from regional MPA networks risks the loss of evolutionarily important populations, threatening resilience and persistence of associated estuarine communities and their ecosystem services. We also observed a high degree of overlap between prioritisation outcomes across targeted measures of genomic variation. As such, by including even single measures of genomic variation, it may be possible to sufficiently represent the evolutionary processes behind the patterns of variation, while simplifying the conservation prioritisation procedure.

genomics↗

Thermal selection drives biodiversity origination across the Atlantic/Indian Ocean boundary

Intraspecific genetic structure in widely distributed marine species often mirrors the boundaries between temperature-defined bioregions. This suggests that the same thermal gradients that maintain distinct species assemblages also drive the evolution of new biodiversity. Ecological speciation scenarios are often invoked to explain such patterns, but the fact that adaptation is usually only identified when phylogenetic splits are already evident makes it impossible to rule out the alternative scenario of allopatric speciation with subsequent adaptation. We integrated large-scale genomic and environmental datasets along one of the worlds best defined marine thermal gradients (the South African coastline) to test the hypothesis that incipient speciation in the sea is due to divergence linked to the thermal environment. We identified temperature-associated gene regions in a coastal fish species that is spatially homogeneous throughout several temperature-defined biogeographical regions on the basis of selectively neutral markers. Based on these gene regions, the species is divided into geographically distinct regional populations. Importantly, the ranges of these populations are delimited by the same ecological boundaries that define distinct infraspecific genetic lineages in co-distributed marine the species, and biogeographical disjunctions in species assemblages. Our results indicate that ecologically-mediated selection represents an early stage of marine speciation in coastal regions that lack physical dispersal barriers.

evolutionary biology↗