DOI: 10.5061/dryad.cjsxksngn
title: Molecular delimitation of evolutionary significant units reveals hidden geographic drivers of extinction risk within island arthropods

description: Aim: Globally, arthropod biodiversity is under threat, with increased risk
 of species-level extinctions, and this threat is particularly acute on
 oceanic islands. A fundamental first step toward understanding extinction
 risk is to understand genetic connectivity among the constituent
 populations of a species. Our aim is to develop and implement a protocol
 to characterise genetic connectivity among island populations within
 arthropod species to reveal otherwise hidden range size drivers of
 extinction. Location: Canary Islands, Spain. Methods: We implement a
 protocol based on mtDNA sequence data for the delimitation of evolutionary
 significant units (ESUs) to evaluate extinction risk among species of
 beetle and spider distributed across multiple islands. Results: Our
 results reveal that more than half of the species analysed are comprised
 of two or more ESUs. We also find that low dispersal ability was a
 significant predictor of ESUs within species of Coleoptera, but with no
 significant difference for Araneae. Main conclusions: Most ESUs are
 consistent with early stage differentiation, or incipient speciation, with
 some exceeding a conservative interspecific threshold, thus indicative of
 cryptic species. We suggest that extending our approach with the
 integration of other species-level traits may provide for a more refined
 predictive framework for understanding extinction risks across island
 arthropod species.
description: Date of data collection: 2012-2021 Geographic
 location of data collection: Canary Islands, Spain. Specifically, laurel
 forests of Tenerife, La Gomera, La Palma and El Hierro.
 This data set was generated to calculate the Nst index usign
 SPAGeDI software to delimited potential ESUs (Evolutionary Significant
 Units) of spider and beetle species through a specific workflow; and to
 calculate GLM and the Spearman Rank-Order Correlation.Genetic data include
 cytochrome oxidase I (COI) sequences of spiders and beetles obtained with
 Sanger sequencing.
description: # Molecular delimitation of evolutionary significant units reveals hidden
 geographic drivers of extinction risk within island arthropods
 [https://doi.org/10.5061/dryad.cjsxksngn](https://doi.org/10.5061/dryad.cjsxksngn) ## Description of the data and file structure This README.txt file was generated on 28-11-2024 by Eduardo Jiménez-García GENERAL INFORMATION Title of Dataset: Data from: Molecular delimitation of evolutionary significant units reveals hidden geographic drivers of extinction risk within island arthropods Author Information ``` Corresponding Investigator 1 Name: Dr Brent Charles Emerson Institution: IPNA-CSIC, San Cristóbal de La Laguna, Canary Islands, Spain Email: bemerson@ipna.csic.es Corresponding Investigator 2 Name: Eduardo Jiménez-García Institution: IPNA-CSIC, San Cristóbal de La Laguna, Canary Islands, Spain Email: e.jimenezgarcia@ipna.csic.es Co-investigador 1 Name: Daniel Suárez Ramos Institution: IPNA-CSIC, San Cristóbal de La Laguna, Canary Islands, Spain Co-investigador 2 Name: Dr. Carmelo Andújar Institution: IPNA-CSIC, San Cristóbal de La Laguna, Canary Islands, Spain Co-investigador 3 Name: Dr. Heriberto López Institution: IPNA-CSIC, San Cristóbal de La Laguna, Canary Islands, Spain ``` Date of data collection: 2012-2021 Recommended citation for this dataset: Jiménez-García et al. (XXXX). Data from: Molecular delimitation of evolutionary significant units reveals hidden geographic drivers of extinction risk within island arthropods ### Files and variables #### 1. Description of dataset This data set was generated to calculate the Nst index to delimited potential ESUs (Evolutionary Significant Units) of spider and beetle species through a specific workflow and the Spearman Rank-Order Correlation. Genetic data include cytochrome oxidase I (COI) sequences obtained with Sanger sequencing in the spider and beetle csv files. 2\. List of abbreviations used on files names or descriptions: ``` TF: Tenerife Island LG: La Gomera Island LP: La Palma Island EH: El Hierro Island COI-3P: Region of the Citochrome Oxidase I sequenced using Jerry-Spat primers. COI-5P: Barcode region. Fragment of Citochrome Oxidase I sequenced using the Folmer primers. Seq: Abbreviation for "sequence" that could be COI-3P in the case of beetles or COI-5P in the case of spiders. Hapl: Haplotype. PBS: Presumed Biological Species. Ind: Individual. Cat: Category (in this case, it refers to the island where the individual was sampled). Lat: Latitude. Lon: Longitude. ESU: Evolutionarily Significant Unit AOO: Area of Occupancy NA: in "4_Spearman.csv", means "Not applicable", because that cell (in that case, ESU 2 AOO or ESU 3 AOO) is not found in the target species and therefore there is no data ``` 3\. File List and descriptions: File 1 Name: 1_Coleoptera.csv Description: CSV file containing all the information needed to calculate the Nst index (overall comparisons, by island pairs, or any combination) using the SPAGeDi software. It contains a total of 8 columns (detailed below) and 2,128 rows (without counting the header) that corresponds to each individual. Columns explained: 1) Species: Name of the species; 2) Hapl: Haplotype corresponding to the individual; 3) PBS: species code; 4) Ind: Individual code; 4) Cat: Category, in this case, the island of origin of the individual that can be the island of TF, LG, LP or EH; 6) Lat: Latitude corresponding to the island in 5; 7) Lon: Longitude corresponding to the island in 5; and 8) Seq: Sequence of the individual, in the case of beetles, the COI-3P region File 2 Name: 2_Spider.csv Description: CSV file containing all the information needed to calculate the Nst index (overall comparisons, by island pairs, or any combination) using the SPAGeDi software. It contains a total of 8 columns (detailed below) and 1,844 rows (without counting the header) that corresponds to each individual. Columns explained: 1) Species: Name of the species; 2) Hapl: Haplotype corresponding to the individual; 3) PBS: species code; 4) Ind: Individual code; 4) Cat: Category, in this case, the island of origin of the individual that can be the island of TF, LG, LP or EH; 6) Lat: Latitude corresponding to the island in 5; 7) Lon: Longitude corresponding to the island in 5; and 8) Seq: Sequence of the individual, in the case of spiders, the COI-5P region File 3 Name: 3_GLM.csv Description: CSV file containing all the data necesary for the binomial GLM. It contains a total of 4 columns and 77 rows (without counting the header) corresponding to each species. Columns explained: 1) ID: Identification of the species; 2) Order: two possibilities, Araneae or Coleoptera; 3) ESU: data in binomial format, 0 represented species with only one delimited ESU while 1 corresponded to species with two or more delimited ESUs; 4) Dispersion: data in binomial format, with 0 corresponding to bad dispersers (wingless or non-ballooner) and 1 corresponding to good dispersers (winged or ballooner). File 4 Name: 4_Spearman.csv Descritption: CSV file containing all the data necesary for the Spearman Rank-Order Correlation. It contains a total of 12 columns and 22 rows (without counting the header) corresponding to each species. Columns explained: 1)Order: Order of the selected species; 2) Family: Family level of the selected species; 3) Species: Identification of the species; 4) Sampled distribution: Sampled distribution of the species on the four target islands; 5) N Island: Number of islands were the species was sampled ; 6); AOO: Area of occupancy of the species, acording to the estimated extesnsión of laurel forest in TF ( 20 km2), LG (35.8 km2), LP (36.4 km2) and EH (8 km2); 7) RANK SP: Ranking from the most threatened (1) to the least threatened (8) level, according to the AOO of the species; 8) N ESU: number of delimited ESUs; 9) ESU 1 AOO: AOO of the first delimited ESU ; 10) ESU 2 AOO: AOO of the second delimited ESU, if it exist (if not, the value appears as NA); 11) ESU 3 AOO: AOO of the third delimited ESU, if it exist (if not, the value appears as NA); 12) RANK ESU: Classification from the most threatened species (1) to the least threatened (7), according to the AOO of the ESUs using an average value in the case of species with several ESUs.