Figure 2

(a) Result of Mantel test for Isolation-by-Distance using Nei’s genetic distance; (b) STRUCTURE showing the division of R. apiculata populations into two main clusters; (c) Sub-structuring of Cluster 1, forming Sub-clusters 1a and 1b; (d) Principal component analysis (PCA) based on pairwise FST of 39 R. apiculata populations, assigning the populations into two distinct clusters that coincide with western (orange color: Straits of Malacca) and eastern (blue color: South China Sea) Peninsular Malaysia and (e) PCA showing Cluster 1 further divided into two sub-clusters.