a Department of Zoology, University of Johannesburg, Kingsway Campus, P.O. Box 524, Auckland Park 2006, South Africa.
b Department of Geography, Environmental Management and Energy Studies, University of Johannesburg, Kingsway Campus, P.O. Box 524, Auckland Park 2006, South Africa.
Genome. 2019 Mar;62(3):170-182. doi: 10.1139/gen-2018-0023. Epub 2019 Mar 13.
Our understanding of how the phylogenetic tree of fishes might be affected by the ongoing extinction risk is poor. This is due to the unavailability of comprehensive DNA data, especially for many African lineages. In addition, the ongoing taxonomic confusion within some lineages, e.g., Cyprinidae, makes it difficult to contribute to the debate on how the fish tree of life might be shaped by extinction. Here, we combine COI sequences and taxonomic information to assemble a fully sampled phylogeny of the African Cyprinidae and investigate whether we might lose more phylogenetic diversity (PD) than expected if currently threatened species go extinct. We found evidence for phylogenetic signal in extinction risk, suggesting that some lineages might be at higher risk than others. Based on simulated extinctions, we found that the loss of all threatened species, which approximates 37% of total PD, would lead to a greater loss of PD than expected, although highly evolutionarily distinct species are not particularly at risk. Pending the reconstruction of an improved multi-gene phylogeny, our results suggest that prioritizing high-EDGE species (evolutionary distinct and globally endangered species) in conservation programmes, particularly in some geographic regions, would contribute significantly to safeguarding the tree of life of the African Cyprinidae.
我们对于鱼类系统发育树可能会受到正在发生的灭绝风险的影响的理解是有限的。这是因为缺乏全面的 DNA 数据,尤其是对于许多非洲谱系。此外,一些谱系(例如鲤科)中持续存在的分类学混乱,使得难以就灭绝可能如何塑造鱼类生命之树展开辩论。在这里,我们结合 COI 序列和分类学信息,构建了非洲鲤科鱼类的全采样系统发育树,并研究了如果目前受威胁的物种灭绝,我们可能会失去比预期更多的系统发育多样性(PD)。我们发现灭绝风险中存在系统发育信号,表明某些谱系可能比其他谱系面临更高的风险。基于模拟灭绝,我们发现,如果所有受威胁物种灭绝,这大约占总 PD 的 37%,则 PD 的损失将超过预期,尽管高度进化独特的物种并不特别面临风险。在重建改进的多基因系统发育之前,我们的研究结果表明,在保护计划中优先考虑高 EDGE 物种(进化独特和全球濒危物种),特别是在一些地理区域,将有助于保护非洲鲤科鱼类的生命之树。