FIGURE 1: Map showing the grouping of sequences from the fish
species Gasterosteus gymnurus (Cuvier, 1829; a junior synonym ofGasterosteus aculeatus , Linnaeus, 1758) into a single
“population” to measure change in intraspecific genetic diversity.
This is one of the 909 time-series datasets in Millette et al. (2020).
This time-series consists of 53 mitochondrial cytochrome c oxidase
subunit 1 (COI) sequences collected at 24 different sampling sites
(colored dots). The sampling sites are all within the 1,000 km distance
threshold set by Millette et al. for being pooled into a population,
despite being located in nine watersheds from six of the major
hydrographical regions in France. Sample sizes are highly uneven across
the time series, with just three sequences from a single site each in
2004, 2007 and 2009, and then 44 sequences from 21 sites in 2013.
Millette et al. (2020) analyzed the trend in nucleotide diversity across
these temporal points, despite the 2013 sample consisting of sequences
pooled across many different regions, while the other years had a single
site, in different regions.