Contrasting phylogeographic patterns of sandy vs. rocky sympatric sister species of supralittoral Tylos isopods in Chile
Data files
Jul 16, 2025 version files 2.33 MB
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README.md
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SupportingDatasetS1.zip
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SupportingDatasetS2.zip
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SupportingDatasetS3.zip
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SupportingDatasetS4.zip
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SupportingTableS1.zip
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Abstract
Sister taxa that have diverged and persisted in sympatry have likely been exposed to the same general environmental changes throughout their evolutionary history and may thus exhibit similar phylogeographies. Here we compare the phylogeographic patterns of two sister species of isopods (genus Tylos) that have broadly overlapping distributions but distinct habitat preferences in the supralittoral zone of Chile. The dynamic geoclimatic history of this region during the Quaternary has been implicated in shaping the evolutionary histories of other coastal taxa. Tylos spinulosus is found in sandy beaches at latitudes ~27–30°S, whereas Tylos chilensis has been found in rocky shores at ~27–33°S and at ~39–42°S. We sampled both species across their ranges (collectively from 20 localities) and obtained sequences from at least one mitochondrial gene for 95 T. chilensis and 41 T. spinulosus. We used phylogenetics and population genetics methods to analyze four single-gene and one concatenated datasets: 12S rDNA (n=130); 16S rDNA (n=31); Cytochrome oxidase subunit I (n=28); Cytochrome b (n=24); concatenation of the four genes (n=24). Both species show high levels of isolation of local populations, consistent with expectations from their limited autonomous dispersal potential. However, they exhibit strikingly different mitochondrial phylogeographic patterns. Tylos chilensis shows evidence of multiple relatively deep divergence events leading to geographically restricted lineages that appear to have persisted over multiple glaciations. Surprisingly, one lineage of T. chilensis was found in geographically distant localities, suggesting the possibility of human-mediated dispersal. Tylos spinulosus appears to have undergone a relatively recent bottleneck followed by a population/range expansion. Differences in life histories and habitat preferences or stochasticity may have contributed to these striking phylogeographic differences. Finally, the high levels of differentiation and isolation among populations indicate that they are highly vulnerable to extirpation. We discuss threats to their persistence, and recommendations for their conservation.
This dataset includes: details about each of the specimens used in this study (Supporting Table S1); input and output files used to generate the haplotype networks depicted in the manuscripts; input and output files of the analyses used to generate the rooted phylogenies depicted in this manuscript (5 datasets: four single-gene and one concatenated); command line and input files used to infer isolation by distance in Tylos spinulosus (Mante test); and input and output files and detailed methodology for testing the molecular clock hypothesis and inferring genetic distances for two genes.
Dataset DOI: 10.5061/dryad.8kprr4xzr
Description of the data and file structure
1. SupportingDatasetS1.zip
contains the files used to generate the haplotype networks for Tylos chilensis and Tylos spinulosus in the program PopArt. Files/folders included:
a. chilensis_haplotype_network folder contains:
- Tylos_Chile_12S_90taxa_chilensis_for_popart.nex input file for PopArt: Tylos chilensis 12S rDNA alignment file in nexus format including the “traits” block where individuals are assigned to populations
- ylos_Chile_12S_90taxa_chilensis_for_popartMJN.nex output file for PopArt for the preceding file.
b. Spinulosus_haplotype_network folder contains:
- Tylos_Chile_12S_spinulosus_for_DNAsp_39tax.nex input file for PopArt: Tylos spinulosus 12S rDNA alignment file in nexus format including the “traits” block where individuals are assigned to populations
- Tylos_Chile_12S_spinulosus_forpopart40tax.nex output file for PopArt for the preceding file.
2. SupportingTableS1.zip
Empty cells mean that data are not applicable.
a. File: TableS1_Sheet_11Jul2025.csv (csv format of the first sheet in TableS1_Workbook_11Jul2025.xlxs)
Descriptions of columns
- Specimen_voucher: Identification number used to distinguish individual specimens in our lab
- GenBank_Acc_12S: GenBank Accession Number of the 12S rDNA sequence (if applicable)
- GenBank_Acc_16S: GenBank Accession Number of the 16S rDNA sequence (if applicable)
- GenBank_Acc_COI: GenBank Accession Number of the Cytochrome Oxidase Subunit I sequence (if applicable)
- GenBank_Acc_Cytb GenBank Accession Number of the Cytochrome b sequence (if applicable)
- Included in concatenated dataset:
- Yes = individual was included in the dataset that concatenated the four genes listed in preceding columns
- No = individual was not included in the dataset that concatenated the four genes listed in preceding columns
- Lat_Lon: Geographical coordinates of locality where specimen was collected in decimal units
- TipLabelwithGB: One of the options for labeling individual in other files (e.g. in trees).
- Locality_simple_name: Simplified name of collection locality
- Organism: Species name
- Name as in nexus file: Specimen label used in DNA sequence alignment file
- Name as in fasta for GenBank: Specimen label used for submission of sequences to GenBank
- TipLabelDraft: Another option for labeling individual in other files (e.g. in trees).
- Desired Tip Label no spaces: Another option for labeling individual in other files (e.g. in trees).
- Names: Another option for labeling individual in other files (e.g. in trees).
- Desired Tip Label spaces: Another option for labeling individual in other files (e.g. in trees).
- Locality Group: name given to nearby localities grouped into a single locality in maps and figures
- species_ind_locality_gp: Another option for labeling individual in other files (e.g. in trees).
- TipLabel_no_species: Another option for labeling individual in other files (e.g. in trees).
- Date: date specimen was collected in the field
- Site: Locality name with additional details for some specimens in parenthesis
- Lat: Latitudinal coordinates of locality where specimen was collected in Degrees, Minutes, and Decimal Seconds
- Long: Longitudinal coordinates of locality where specimen was collected in Degrees, Minutes, and Decimal Seconds
- Fixation: when known, specimen preservation method. ETOH = ethanol
- Collectors: names of individuals who collected specimens. In parenthesis, their institutions. Ulagos = Universidad de los Lagos; UCN = Universidad Catolica del Norte
- Remarks: remarks on the specimens or the collection site during the time of collection
- Molecular Work: First name of individual lab member who performed molecular work
- “Lat Degrees” through “long decimal”: series of columns with used to convert formats of geographical coordinates
- Sequence_ID: Another option for labeling individual in other files (e.g. in trees).
- Fwd_primer_name: name of the forward primer used to amplify and sequence the 12S rDNA gene
- Fwd_primer_seq: sequence of the forward primer used to amplify and sequence the 12S rDNA gene
- Rev_primer_name: name of the reverse primer used to amplify and sequence the 12S rDNA gene
- Rev_primer_seq: sequence of the reverse primer used to amplify and sequence the 12S rDNA gene
- Collected_by: names of individuals who collected specimens. In parenthesis, their institutions. Ulagos = Universidad de los Lagos; UCN = Universidad Catolica del Norte
- Collection_date: date specimen was collected in the field
- Country: country where specimen was collected
- Haplotype_Label_12SrDNA: 12S rDNA gene haplotype label
- Haplotype label unique: list of unique 12S rDNA gene haplotypes
- counts per haplotype: number of individuals per haplotype in the preceding column
- haplotype frequency: frequency of haplotype in the preceding column (6 decimals)
- frequency rounded: values in the preceding column rounded to 2 decimals
b. File: TableS1_Sheet_11Jul2025.csv (csv format of the first sheet in TableS1_Workbook_11Jul2025.xlxs)
- Sheet “TableS1” contains essentially the same data as “TableS1_Sheet_11Jul2025.csv”, but contains Excel formulas used to generate some of the contents. For description of columns, see for file “TableS1_Sheet_11Jul2025.csv”.
- Sheet “sorted_by_sp_lat_date” contains essentially the same data as Sheet “TableS1” but reordered by species, latitude, and date, and color coded. Cell colors are intended to closely match locality/region colors used in figures. Different font colors within the same cell color are used to distinguish different localities within a region or different collection years within the same locality/region.
- Sheet “Lat_Longs_Unique_Counts” contains the commands used to find unique geographic coordinates among the rows of sheet “TableS1”, and counts of the rows per each unique geographic coordinate values
- Sheet “T_spi_01&05haps_individuals” contains a list of the specimens of Tylos spinulosus assigned to haplotypes T_spi_01 and T_spi_05
- Sheet “summary_table” was used to generate the Table 1 in the main text.
3. SupportingDatasetS2.zip contains 5 folders.
Each folder groups the files associated with the phylogenetic analyses of the four single-gene datasets and the concatenated dataset. Files names ending with “.phy” are the Phylip-formatted alignment files used in each analysis. In some cases, nexus- (.nex) and fasta- (.fas) formatted alignment files are also included. Files including “TipLabels” in the name, were used to replace tip label names in the resulting trees using the FigTree app. All remaining files are output files of the IQTree analyses. File names ending with “.log” provide the command line used and details on the output file names and contents. List of 5 folders:
a. 12S_rDNA_gene
b. 16SrDNA_gene
c. COI_gene
d. Concatenated
e. Cytb_gene
4. SupportingDatasetS3.zip
contains the input files and commands used to run the Mantel test. List of files:
a. SuccessfulMantel_commands_results.txt contains the command line used in R
b. Fst_matrix.txt contains the pairwise Fst distances used in the Mantel test (.txt format)
c. Fst_matrix.csv contains the pairwise Fst distances used in the Mantel test (.csv format)
d. geog_matrix.csv contains the pairwise geographic distances used in the Mantel test (.csv format)
e. geog__no_L_matrix.csv contains the same information as “geog_matrix.csv”, but excludes the Lagunillas locality
f. Fst_matrix_no_L.csv
contains the same information as “Fst_matrix.csv”, but excludes the Lagunillas locality
5. SupportingDatasetS4.zip
contains 3 folders and 2 files that collectively include the input files, commands, and formulas used to run the test the molecular clock hypothesis for the Cytb and COI genes, and the estimated Kimura-2-parameter (K2P) distances. List of files/folders:
a. Methods_to_test_molecular_clock_and_estimate_pairwise_distances folder: contains the instructions and file names of the pipeline followed for these analyses in two formats
- i. Methods_to_test_molecular_clock_and_estimate_pairwise_distances.md in MarkDown format
- ii. Methods_to_test_molecular_clock_and_estimate_pairwise_distances.pdf in pdf format
b. COI_dataset contains the files used to generate the tree used to test the molecular clock hypothesis for the COI gene dataset. Please see description of Supporting Dataset S2 for interpretation of files names.
c. Cytb_dataset contains the files used to generate the tree used to test the molecular clock hypothesis for the Cytb gene dataset. Please see description of Supporting Dataset S2 for interpretation of files names.
d. lrt_k2p_coi_cytb.xlsx is an Excel workbook containing processed output of Paup*.
List of sheets:
- i. k2p_cytb_271chars_24taxa contains the Kimura-2-parameter (K2P) distances inferred by Paup* for the Cytb dataset.
- ii. k2p_coi_159chars contains the Kimura-2-parameter (K2P) distances inferred by Paup* for the COI dataset
- iii. molec_clock_tests contains the Excel formulas used to conduct the Likelihood ratio test (LRT) to test the molecular clock hypothesis.
e. k2p_cytb_271chars_24taxa.csv has identical contents to sheet “k2p_cytb_271chars_24taxa”, but in csv format
f. k2p_coi_159chars.csv has identical contents to sheet “k2p_coi_159chars”, but in csv format.