4.2 More accurate evolutionary history of C. japonica
The presented genomic resource can help us better understand the evolutionary history of C. japonica . The differentiation of conserved single-copy orthologous genes always leads to species differentiation; thus, we believe that the evolutionary history ofC. japonica can be more accurately deetermined using widespread single-copy orthologous genes (Liang et al., 2013; Fitch, 1970). In the present study, 968 single-copy orthologous genes were obtained and then applied to construct the phylogenetic relationship of C. japonica . Expectedly, the constructed phylogenetic structure is considerably congruent with the prevailing morphological and molecular biological views that crabs (P. trituberculatus and C. japonica ) from family Portunidae eventually cluster into one branch. Moreover, the evolutionary sequence of C. japonica was identified based on differentiation times, and these results provided evidence to prove the existence of “carcinization” (Keiler et al., 2017; Cui et al., 2021). In fact, 1,138 unique gene families were found in the genome, and these gene families can contribute to C. japonica -specific adaptation (Wissler et al., 2013). Additionally, the relatively evolution rates of different species may also mean differences in environmental stability (Tang et al., 2020).