Genetic structure is stronger across human-impacted habitats than among islands in the coral Porites lobata .

Autor: Tisthammer KH; Kewalo Marine Laboratory, University of Hawaii at Manoa, Honolulu, HI, United States of America.; Department of Biology, San Francisco State University, San Francisco, CA, United States of America., Forsman ZH; Hawaii Institute of Marine Biology, University of Hawaii at Manoa, Kaneohe, HI, United States of America., Toonen RJ; Hawaii Institute of Marine Biology, University of Hawaii at Manoa, Kaneohe, HI, United States of America., Richmond RH; Kewalo Marine Laboratory, University of Hawaii at Manoa, Honolulu, HI, United States of America.
Jazyk: angličtina
Zdroj: PeerJ [PeerJ] 2020 Feb 18; Vol. 8, pp. e8550. Date of Electronic Publication: 2020 Feb 18 (Print Publication: 2020).
DOI: 10.7717/peerj.8550
Abstrakt: We examined genetic structure in the lobe coral Porites lobata among pairs of highly variable and high-stress nearshore sites and adjacent less variable and less impacted offshore sites on the islands of Oahu and Maui, Hawaii. Using an analysis of molecular variance framework, we tested whether populations were more structured by geographic distance or environmental extremes. The genetic patterns we observed followed isolation by environment, where nearshore and adjacent offshore populations showed significant genetic structure at both locations (AMOVA F ST = 0.04∼0.19, P  < 0.001), but no significant isolation by distance between islands. Strikingly, corals from the two nearshore sites with higher levels of environmental stressors on different islands over 100 km apart with similar environmentally stressful conditions were genetically closer ( F ST = 0.0, P = 0.73) than those within a single location less than 2 km apart ( F ST = 0.04∼0.08, P  < 0.01). In contrast, a third site with a less impacted nearshore site (i.e., less pronounced environmental gradient) showed no significant structure from the offshore comparison. Our results show much stronger support for environment than distance separating these populations. Our finding suggests that ecological boundaries from human impacts may play a role in forming genetic structure in the coastal environment, and that genetic divergence in the absence of geographical barriers to gene flow might be explained by selective pressure across contrasting habitats.
Competing Interests: Robert J. Toonen is an Academic Editor and Section Editor for Aquatic Biology for PeerJ.
(©2020 Tisthammer et al.)
Databáze: MEDLINE
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