Data from: the two faces of secondary contact on islands: introgressive hybridization between endemics and reproductive interference between endemics and introduced species
Data files
Dec 14, 2023 version files 1.18 MB
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all_endemic_species.csv
197.21 KB
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csv_descriptions.xlsx
13.05 KB
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divergence_times_endemics.csv
40.22 KB
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lit_search_data_analysis.R
18.59 KB
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lit_search_full_dataset.csv
809.20 KB
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README.md
2.32 KB
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taxa.csv
97.16 KB
Abstract
Aim: Hybridization is thought to have played an important role in shaping the evolutionary history of diverse island taxa. Here, we propose an ecological and evolutionary framework for understanding the causes and consequences of heterospecific mating on islands – with and without introgressive hybridization. We use this framework to support our main contention that cases of secondary contact among endemic species should commonly result in introgressive hybridization whereas cases of contact between endemic and introduced species should commonly result in reproductive interference – resulting in two qualitatively different faces of secondary contact on islands.
Location: Canary Islands, Galapagos, New Zealand, Caribbean, and Hawaii.
Taxa: 705 vertebrate, invertebrate, and plant species spanning 167 genera and 99 families.
Methods: Using a quantitative analysis of empirical research on secondary contact on islands, we weigh evidence for the drivers of secondary contact and heterospecific mating on islands. In particular, we compare cases of secondary contact between endemic species versus secondary contact between endemic and introduced species.
Results: We find that three main drivers of secondary contact and heterospecific mating on islands most frequently reported in the literature are disturbance, long-distance (e.g. inter-island) dispersal, and compromised assortative mating. We find support for the hypothesis that introgression is a more common outcome between endemic species while reproductive interference is a more common outcome between endemic and introduced species.
Main conclusions: We conclude that there are biological reasons to predict secondary contact and heterospecific mating to be common on islands for all taxa, but that the consequence of secondary contact is categorically different for contact between endemic species and contact between endemic and introduced species. We conclude that the former likely explains the apparent frequency of hybridization on islands, while the latter presents a cryptic and underappreciated conservation threat.
README: The two faces of secondary contact on islands: Introgressive hybridization between endemics and reproductive interference between endemics and introduced species
General Information
This data_availability directory contains all of the scripts and results necessary to recreate the analyses and plots used in the article "Reatini et al. (2023)The two faces of secondary contact on islands: Introgressive hybridization between endemics and reproductive interference between endemics and introduced species
Below is a description of the results files, the meaning of the column names within those files, and the corresponding analyses and plots for which they were used. A description of the script used to carryout the analyses follows.
Results Files
Below is a brief description of each of the results files and the figures they were used to produce:
Column name descriptions for all results files can be found in the file "csv_descriptions.xlsx"
lit_search_full_dataset.csv - dataset of all relevant articles collected from the literature search on sescondary contact on islands. Used in lit_search_data_analysis.R to produce panel A of Figure 1 and panel D of Figure 2.
divergence_times_endemics.csv - all pairs of taxa with weak intrinsic barriers and divergence estimates used in lit_search_data_analysis.R to produce panel E of Figure 3.
taxa.csv - taxonomic data and distribution data for each individual parental taxon extracted from lit_search_full_dataset.csv. Used in lit_search_data_analysis.R to produce the subplots in panel A of Figure 3 and the results in Table 1.
all_endemic_species.csv - all endemic angiosperm and vertebrate species recorded from species checklists for each archipelago. Used in lit_search_data_analysis.R to produce the results in Table 1.
Note on NA values and empty cells: all NA values and empty cells in the above csv files represent data points that were unavailable or not applicable for the category in question.
Scripts
lit_search_data_analysis.R - used to carry out all analyses in the manuscript and to produce subplots in Figures 1,2 & 3.
Package versions:
tidyverse version 1.3.2
plotly version 4.10.1
dplyr version 1.1.2
ggplot2 version 3.4.2
VennDiagram version 1.7.3
knitr version 1.43
UpSetR version 1.4.0
ComplexUpset version 1.3.3
Methods
This dataset includes an analysis of empirical research regarding secondary contact on islands gathered from a literature search. The research articles were collected from a search on Scopus, the titles and abstracts of each article were screened, and then the full texts were screened for relevance. We then extracted data surrounding the causes and consequences of heterospecific mating between endemic species and endemic and introduced species. Divergence time estimates were collected for pairs of taxa when available, and each individual taxon was extracted in order to assess the prevalence of hybridization among endemic species. All statistical analyses were performed using the scripts included in the present dataset.