In Thailand, the forest crested lizard, Calotes emma consists of two subspecies, C. emma alticristatus Schmidt, 1925 and C. emma emma Gray, 1845. This
study was performed to determine the genetic diversity and differentiation of C. emma from 16 different localities throughout Thailand. A total of 116
samples were analyzed using the mitochondrial cytochrome c oxidase subunit 1 (CO1). Of these, 65 and 51 of C. e. alticristatus and C. e. emma were
classified into 23 (Ni - N23) and 21 (S1 - S21) haplotypes, respectively. There was no shared haplotype between subspecies or between different populations
within each subspecies. These haplotypes were classified into four (north-A to north-D) and three (south-A to south-C) haplogroups of C. e. alticristatus and
C. e. emma, respectively. Phylogenetic analyses retrieved four lineages (classified as I to IV). Lineages I and II contained the four haplogroups of C. e.
alticristatus, whereas lineage llt and IV contained three haplogroups of C. e. emma. These two subspecies live separately in different climate zones, i.e. C. e.
alticristatus is found in an equatorial winter dry climate, whereas C. e. emma inhabits areas with an equatorial monsoonal climate.