Figure Legends
Figure 1. (a) Map of study regions and presence records used in
this study. Red and blue points represent sample collection locations
for molecular analyses in the Western Tropical Indo-Pacific (WTIP) and
the Central Tropical Indo-Pacific (CTIP). Gray crosses show presence
records used for the species distribution models. (b) Network of
microsatellite genetic differentiation (Cavalli-Sforza and Edwards chord
distances). The topology results from pruning the network for pairwise
genetic distances <0.534. The smallest chord distance (0.499)
between the WTIP and CTIP lineages is shown. (c) Genetic lineage
division over space based on STRUCTURE clustering (k = 2). Population
abbreviations are the same as in Hernawan et al. (2017) and
Jahnke et al. (2019a), and their classification to network
analysis is in agreement with that of STRUCTURE (Fig. 1c).Figure 2. The realized
niches for the two lineages of Thalassia hemprichii quantified
via eight-dimensional hypervolumes. Circles with white rims indicate
hypervolume centroids. Boundaries and shapes of hypervolumes were
delineated by 10,000 points randomly sampled within each hypervolume.
The photograph depicts T. hemprichii.Figure 3. Present-day continuous (a, b) and binary (c, d)
habitat suitability predictions for Thalassia hemprichii by
lineage-level (a, c) and species-level (b, d) Maxent models. Dashed
lines represent the equator.
Figure 4 . Changes in
continuous (a, b) and binary (c, d) habitat suitability forThalassia hemprichii projected by lineage-level (a, c) and
species-level (b, d) Maxent models under the RCP 8.5 scenario in the
2050s. Dashed lines indicate the equator. The category “stable”
represents areas predicted to be suitable under both present-day and
future climatic conditions, “loss” indicates areas predicted to be
suitable under present-day conditions but unsuitable in the future, and
“gain” indicates areas predicted to be unsuitable under present-day
conditions but suitable in the future.