Random forest assessment of correlation between environmental factors and genetic differentiation of populations: Case of marine mussels Mytilus

Summary: The novel machine learning technique Random Forest (RF) was used to test if the genetic differentiation of populations of marine species may be related to any of the key environmental variables known to shape species distributions. The study was performed in North and Baltic Sea characteriz...

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Main Authors: Tomasz Kijewski, Malgorzata Zbawicka, Jakob Strand, Hans Kautsky, Jonne Kotta, Merli Rätsep, Roman Wenne
Format: Article
Language:English
Published: Elsevier 2019-01-01
Series:Oceanologia
Online Access:http://www.sciencedirect.com/science/article/pii/S0078323418300927
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author Tomasz Kijewski
Malgorzata Zbawicka
Jakob Strand
Hans Kautsky
Jonne Kotta
Merli Rätsep
Roman Wenne
author_facet Tomasz Kijewski
Malgorzata Zbawicka
Jakob Strand
Hans Kautsky
Jonne Kotta
Merli Rätsep
Roman Wenne
author_sort Tomasz Kijewski
collection DOAJ
description Summary: The novel machine learning technique Random Forest (RF) was used to test if the genetic differentiation of populations of marine species may be related to any of the key environmental variables known to shape species distributions. The study was performed in North and Baltic Sea characterized by strong gradients of environmental factors and almost continuous distributions of Mytilus mussel populations. Assessment of the species identity was performed using four nuclear DNA markers, and previously published single nucleotide polymorphism (SNP) data. A general pattern of cline variation was observed with increasing Mytilus trossulus share towards the eastern Baltic Sea. Average allele share rose to 61% in Höga Kusten, Gulf of Bothnia. All Baltic Sea samples revealed a strong introgression of Mytilus edulis and a limited introgression of M. trossulus through the Danish Straits.The studied environmental variables described 67 and 68% of the variability in the allele frequencies of M. edulis and M. trossulus. Salinity defined over 50% of the variability in the gene frequencies of the studied Mytilus spp. populations. Changes along this environmental gradient were not gradual but instead a significant shift from gene dominance was found at a salinity of 12 PSU. Water temperature and the trophic status of the sea area had only moderate association with the gene frequencies. The obtained results showed that the novel machine learning technique can be successfully used for finding correlations between genetic differentiation of populations and environmental variables and for defining the functional form of these linkages. Keywords: Marine environment, Spatial distribution, Seascape genetics, Nuclear DNA markers EFbis, Glu-5′, ITS, M7 and Single Nucleotide Polymorphism, Baltic Sea
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spelling doaj.art-32a760553f6c4f61b9cfb6c5aeae202d2022-12-22T01:56:28ZengElsevierOceanologia0078-32342019-01-01611131142Random forest assessment of correlation between environmental factors and genetic differentiation of populations: Case of marine mussels MytilusTomasz Kijewski0Malgorzata Zbawicka1Jakob Strand2Hans Kautsky3Jonne Kotta4Merli Rätsep5Roman Wenne6Institute of Oceanology, Polish Academy of Sciences, Sopot, PolandInstitute of Oceanology, Polish Academy of Sciences, Sopot, PolandArctic Research Centre, Department of Bioscience, Aarhus University, Aarhus, DenmarkDepartment of Ecology, Environment and Plant Sciences, Stockholm University, SwedenEstonian Marine Institute, University of Tartu, Tallinn, EstoniaEstonian Marine Institute, University of Tartu, Tallinn, EstoniaInstitute of Oceanology, Polish Academy of Sciences, Sopot, Poland; Corresponding author at: Institute of Oceanology, Polish Academy of Sciences, Powstańców Warszawy 55, 81-712 Sopot, Poland. Tel.: +48 58 7311763; fax: +48 58 5512130.Summary: The novel machine learning technique Random Forest (RF) was used to test if the genetic differentiation of populations of marine species may be related to any of the key environmental variables known to shape species distributions. The study was performed in North and Baltic Sea characterized by strong gradients of environmental factors and almost continuous distributions of Mytilus mussel populations. Assessment of the species identity was performed using four nuclear DNA markers, and previously published single nucleotide polymorphism (SNP) data. A general pattern of cline variation was observed with increasing Mytilus trossulus share towards the eastern Baltic Sea. Average allele share rose to 61% in Höga Kusten, Gulf of Bothnia. All Baltic Sea samples revealed a strong introgression of Mytilus edulis and a limited introgression of M. trossulus through the Danish Straits.The studied environmental variables described 67 and 68% of the variability in the allele frequencies of M. edulis and M. trossulus. Salinity defined over 50% of the variability in the gene frequencies of the studied Mytilus spp. populations. Changes along this environmental gradient were not gradual but instead a significant shift from gene dominance was found at a salinity of 12 PSU. Water temperature and the trophic status of the sea area had only moderate association with the gene frequencies. The obtained results showed that the novel machine learning technique can be successfully used for finding correlations between genetic differentiation of populations and environmental variables and for defining the functional form of these linkages. Keywords: Marine environment, Spatial distribution, Seascape genetics, Nuclear DNA markers EFbis, Glu-5′, ITS, M7 and Single Nucleotide Polymorphism, Baltic Seahttp://www.sciencedirect.com/science/article/pii/S0078323418300927
spellingShingle Tomasz Kijewski
Malgorzata Zbawicka
Jakob Strand
Hans Kautsky
Jonne Kotta
Merli Rätsep
Roman Wenne
Random forest assessment of correlation between environmental factors and genetic differentiation of populations: Case of marine mussels Mytilus
Oceanologia
title Random forest assessment of correlation between environmental factors and genetic differentiation of populations: Case of marine mussels Mytilus
title_full Random forest assessment of correlation between environmental factors and genetic differentiation of populations: Case of marine mussels Mytilus
title_fullStr Random forest assessment of correlation between environmental factors and genetic differentiation of populations: Case of marine mussels Mytilus
title_full_unstemmed Random forest assessment of correlation between environmental factors and genetic differentiation of populations: Case of marine mussels Mytilus
title_short Random forest assessment of correlation between environmental factors and genetic differentiation of populations: Case of marine mussels Mytilus
title_sort random forest assessment of correlation between environmental factors and genetic differentiation of populations case of marine mussels mytilus
url http://www.sciencedirect.com/science/article/pii/S0078323418300927
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