Ecological processes, non-ecological processes or a combination of both may cause reproductive isolation and speciation, but their specific roles and potentially complex interactions in evolutionary radiations remain poorly understood, which defines a central knowledge gap at the interface of microevolution and macroevolution. Here I examine genome scans in combination with phenotypic and environmental data to disentangle how ecological and non-ecological processes contributed to population differentiation and speciation in an ongoing radiation of Lanistes gastropods from the Malawi Basin. I found a remarkable hierarchical structure of differentiation mechanisms in space and time: neutral and mutation-order processes are older and occur mainly between regions, whereas more recent adaptive processes are the main driver of genetic differentiation and reproductive isolation within regions. The strongest differentiation occurs between habitats and between regions, i.e. when ecological and non-ecological processes act synergistically. The structured occurrence of these processes based on the specific geographic setting and ecological opportunities strongly influenced the potential for evolutionary radiation. The results highlight the importance of interactions between various mechanisms of differentiation in evolutionary radiations, and suggest that non-ecological processes are important in adaptive radiations, including those of cichlids. Insight into such interactions is critical to understanding large-scale patterns of organismal diversity.
Environmental data at sampling localities
[primary data file] This file contains information on five environmental variables documented at the studied sample localities
LanistesEnvData.txt
Results of BayeScan
[output file] This file contains the results of the BayeScan analysis. This output file has been used to identify loci that are putatively under selection.
BayeScan_Output_fst.txt
Raw amplified fragment length polymorphism dataset (NA = 9)
[primary data file] This file contains the raw AFLP dataset with NA’s coded as '9'.
gen_morph_pop_nine.txt
Raw amplified fragment length polymorphism dataset (NA = ?)
[primary data file] This file contains the raw AFLP dataset with NA’s coded as ‘?’.
gen_morph_pop_questionmark.txt
Information on genetic diversity
[output file] This file contains results from analysis of the AFLP dataset with AFLPsurv. Some of the tests reported in the paper have been performed on this output file.
AFLPsurv-geneticdiversity.txt
Population pairwise Fst data
[output file] This file contains results from analysis of the AFLP dataset with AFLPsurv. These results have been used as input for the Fst-Pst comparisons.
AFLPsurv-PopPairwiseFST.txt
1000 Bootstrap replicates on Population pairwise Fsts
[output file] This file contains results from analysis of the AFLP dataset with AFLPsurv. These results have been used to calculate 95 % confidence intervals on the Population pairwise Fst data.
LanistesAFLPsurv_pairwiseFSTreplicates.txt
Geometric morphometric dataset
[primary data file] This file contains information on individual specimens and the coordinates from semilandmark morphometrics after Procrustes superimposition and semilandmark alignment with perpendicular projection. This dataset has been used as the dataset for all subsequent morphometric analyses including ordination and the calculation of population pairwise Psts.
LanistesAFLP-MorphometricCoordsCS.txt
Pst summary statistics (from 1000 bootstraps)
[output file] These summary statistics have been calculated from 1000 bootstrap replicates of the geometric morphometric dataset and subsequent Pst calculations. These summary statistics are used for Fst-Pst comparisons.
PST_1000BootstrapReplicates.txt
Fst summary statistics (from 1000 bootstraps)
[output file] These summary statistics have been calculated from 1000 bootstrap replicates of AFLPsurv. These summary statistics are used for Fst-Pst comparisons.
FST_95CIfromBootstrappingAFLPsurv.txt
Data for Fst-Pst comparisons
[input file] This file contains the compiled data from Pst and Fst calculations in an organized format to do Fst-Pst comparisons.
PstFst-comparisondataFinal.txt
Input for analyses with SPAGeDi (Basin-wide)
[input file] This file is the file used to do basin-wide analyses with SPAGeDi.
Lanistes_spagedi_Final.txt
Input for analyses with SPAGeDi (Northern region)
[input file] This file is the file used to do SPAGeDi-analyses on populations from the northern region.
Lan_north_spagedi_Final.txt
Input for analyses with SPAGeDi (Southern region)
[input file] This file is the file used to do SPAGeDi-analyses on populations from the southern region.
Lan_south_spagedi_Final.txt
SPAGeDI output summary for Fi = 0.0
[output file] This file summarizes the results of basin-wide and regional analyses with SPAGeDi under an inbreeding coefficient Fi = 0.0 (thus under Hardy-Weinberg equilibrium).
kinship-distance_matrix_HW_Fi0_0.txt
SPAGeDI output summary for Fi = 0.2
[output file] This file summarizes the results of basin-wide and regional analyses with SPAGeDi under an inbreeding coefficient Fi = 0.2.
kinship-distance_matrix_Fi0_2.txt
SPAGeDI output summary for Fi = 0.4
[output file] This file summarizes the results of basin-wide and regional analyses with SPAGeDi under an inbreeding coefficient Fi = 0.4.
kinship-distance_matrix_Fi0_4.txt
SPAGeDI output summary for Fi = 0.6
[output file] This file summarizes the results of basin-wide and regional analyses with SPAGeDi under an inbreeding coefficient Fi = 0.6.
kinship-distance_matrix_Fi0_6.txt