On Long-Term Species Coexistence in Five-Species Evolutionary Spatial Cyclic Games with Ablated and Non-Ablated Dominance Networks
I present a replication and, to some extent, a refutation of key results published by Zhong, Zhang, Li, Dai, & Yang in their 2022 paper "Species coexistence in spatial cyclic game of five species" (Chaos, Solitons and Fractals, 156: 111806), where ecosystem species coexistence was explored via simulation studies of the evolutionary spatial cyclic game (EO_SCPLOWSCGC_SCPLOW) Rock-Paper-Scissors-Lizard-Spock (RO_SCPLOWPSLSC_SCPLOW) with certain predator-prey relationships removed from the games "interaction structure", i.e. with specific arcs ab-lated in the EO_SCPLOWSCGC_SCPLOWs dominance network, and with the EO_SCPLOWSCGC_SCPLOW run for 105 Monte Carlo Steps (O_SCPLOWMCSC_SCPLOW) to identify its asymptotic behaviors. I replicate the results presented by Zhong et al. for interaction structures with one, two, three, and four arcs ablated from the dominance network. I then empiri-cally demonstrate that the dynamics of the RO_SCPLOWPSLSC_SCPLOW EO_SCPLOWSCGC_SCPLOW have sufficiently long time constants that the true asymptotic outcomes can often only be identified after running the ablated EO_SCPLOWSCGC_SCPLOW for 107O_SCPLOWMCSC_SCPLOW or longer, and that the true long-term outcomes can be markedly less diverse than those reported by Zhong et al. as asymptotic. Finally I demonstrate that, when run for sufficiently many O_SCPLOWMCSC_SCPLOW, the original unablated RO_SCPLOWPSLSC_SCPLOW system exhibits essentially the same asymptotic outcomes as the ablated RO_SCPLOWPSLSC_SCPLOW systems, and in this sense the only causal effect of the ablations is to alter the time required for the system to converge to the long-term asymptotic states that the unablated system eventually settles to anyhow. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=117 SRC="FIGDIR/small/615336v1_ufig1.gif" ALT="Figure 1"> View larger version (44K): org.highwire.dtl.DTLVardef@119803borg.highwire.dtl.DTLVardef@131bfcdorg.highwire.dtl.DTLVardef@1272f6borg.highwire.dtl.DTLVardef@19a4473_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LII replicate key results from Zhong et al. (2022) where biodiversity was explored via the game Rock-Paper-Scissors-Lizard-Spock (RO_SCPLOWPSLSC_SCPLOW). C_LIO_LIZhong et al. reported results from RO_SCPLOWPSLSC_SCPLOW games where specific predatorprey interactions were ablated from the games dominance network. C_LIO_LIMy replication reveals problems in Zhong et al.s design of experiments. C_LIO_LIZhong et al. did not run their simulations for sufficiently long to reveal the true asymptotic behavior of the ablated RO_SCPLOWPSLSC_SCPLOW systems. C_LIO_LIZhong et al. did not present control outcomes from the unablated RO_SCPLOWPC_SCPLOW-O_SCPLOWSLSC_SCPLOW system, so there is no baseline data for comparison to the treatment outcomes. C_LIO_LII present results from simulations that are run for 100 to 1000 times longer than the experiments reported by Zhong et al., thereby revealing the true asymptotic behaviors of the system. C_LIO_LIThe asymptotic outcomes are remarkably uniform - practically indistinguishable - in the cases where one, two, or three arcs are ablated from the RO_SCPLOWPSLSC_SCPLOW dominance network. C_LIO_LIMy asymptotic results for the baseline original unablated system are also very similar to those for the one-two- and three-ablation systems. C_LIO_LIMy results question whether the ablations have any effect other than speeding the systems convergence to its eventual asymptotic state. C_LIO_LIResults from Zhong et al.s four-ablation system do not fit so well with the lower-ablation-count systems: potential reasons for this, and avenues for further research on it, are discussed. C_LI