Strong species structure but weak geographical structure in demersal Lake Victoria cichlids.

van Rijssel, Jacco C; Moser, Florian N; Mwaiko, Salome; Seehausen, Ole (2022). Strong species structure but weak geographical structure in demersal Lake Victoria cichlids. Ecology and evolution, 12(12), e9669. John Wiley & Sons, Inc. 10.1002/ece3.9669

[img]
Preview
Text
Ecology_and_Evolution_-_2022_-_Rijssel_-_Strong_species_structure_but_weak_geographical_structure_in_demersal_Lake_Victoria.pdf - Published Version
Available under License Creative Commons: Attribution (CC-BY).

Download (2MB) | Preview

Studying phenotypic and genetic differentiation between very young species can be very informative with regard to learning about processes of speciation. Identifying and characterizing genetic species structure and distinguishing it from spatial genetic structure within a species is a prerequisite for this and is often not given sufficient attention. Young radiations of cichlid fish are classical speciation study systems. However, it is only during the past decade that population genomics based on next-generation sequencing has begun to provide the power to resolve species and distinguish speciation from spatial population structure for the youngest of these radiations. The Lake Victoria haplochromine cichlids constitute the youngest large cichlid fish radiation, probably <20,000 years old. Earlier work showed that communities of rocky reef cichlids are composed of many reciprocally monophyletic species despite their very recent origins. Here, we build on this work by studying assemblages of offshore demersal cichlids, adding analyses of within-species spatial structure to the sympatric species structure. We sampled seven multispecies communities along a 6-km-long transect from one side of the Mwanza Gulf to the other side. We investigated whether phenotypically diagnosed putative species are reciprocally monophyletic and whether such monophyly is stable across species geographic ranges. We show that all species are genetically strongly differentiated in sympatry, that they are reciprocally monophyletic, and that monophyly is stable across distribution ranges. We found significant differentiation between geographically distinct populations in two species, but no or weak isolation by distance. We further found subtle but significant morphological differences between all species and a linear relationship between genomic and morphological distance which suggests that differences in morphology begin to accumulate after speciation has already affected genome-wide restrictions of gene flow.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Department of Biology > Institute of Ecology and Evolution (IEE)
08 Faculty of Science > Department of Biology > Institute of Ecology and Evolution (IEE) > Aquatic Ecology

UniBE Contributor:

Seehausen, Ole

Subjects:

500 Science > 570 Life sciences; biology

ISSN:

2045-7758

Publisher:

John Wiley & Sons, Inc.

Language:

English

Submitter:

Pubmed Import

Date Deposited:

06 Jan 2023 11:30

Last Modified:

06 Jan 2023 23:22

Publisher DOI:

10.1002/ece3.9669

PubMed ID:

36582774

Uncontrolled Keywords:

Lake Victoria RAD‐tag sequencing cichlids haplochromines hybridization speciation species delineation

BORIS DOI:

10.48350/176720

URI:

https://boris.unibe.ch/id/eprint/176720

Actions (login required)

Edit item Edit item
Provide Feedback