Ancestral Hybridization Yields Evolutionary Distinct Hybrids Lineages and Species Boundaries in Crocodiles, Posing Unique Conservation Conundrums

摘要: Interspecific hybridization can lead to adaptation and speciation, especially in the context of recent radiations. The emblematic Crocodylus (true crocodiles) is most broadly distributed, ecologically diverse, species-rich crocodylian genus. Nonetheless, their within-species evolutionary processes are poorly resolved mainly due potential for hybridization. Notably, outcomes when ancient involves long-lived species, like crocodiles, remain largely unexplored. Here, we evaluate genomic admixture between American (Crocodylus acutus) Morelet’s moreletii) demonstrate that this system challenges definition species boundaries poses a triple conservation conundrum: what has been recognized as C. acutus actually two distinct therefore its taxonomic reassessment needed; identified hybrids lineages, which genetically discernible from parental species; remaining moreletii populations evidence likely extinction and/or evolution via Hence, crocodiles’ lineages warrant recognition need urgent efforts.