Doctorado en Ciencias, Instituto de Ecología, A.C., Red de Estudios Moleculares Avanzados, Carretera Antigua a Coatepec 351, Veracruz, Mexico.
CONACyT Research Fellow, Instituto de Ecología A. C., Red de Estudios Moleculares Avanzados, Carretera Antigua a Coatepec 351, Veracruz, Mexico.
J Fish Biol. 2021 Aug;99(2):396-410. doi: 10.1111/jfb.14727. Epub 2021 Apr 6.
The family Profundulidae is a group of small-sized fish species distributed between southern Mexico and Honduras, where they are frequently the only fish representatives at higher elevations in the basins where they occur. We characterized their ecological niche using different methods and metrics drawn from niche modelling and by re-examining phylogenetic relationships of a recently published molecular phylogeny of this family to gain a better understanding of its biogeographic and evolutionary history. We assessed both lines of evidence from the perspective of niche conservatism to set a foundation for discussing hypotheses about the processes underlying the distribution and evolution of the group. In fish clades where the species composition is not clear, we examined whether niche classification could be informative to discriminate groups geographically and ecologically consistent with any of the different hypotheses of valid species. The characterization of the ecological niche was carried out using the Maxent algorithm under different parameterizations and the projection of the presence on the main components of the most relevant environmental coverage, and the niche comparison was calculated with two indices (D and I), both in environmental space and in that projected geographically. With the molecular data, a species tree was generated using the *BEAST method. The comparison of these data was calculated with an age-overlap correlation test. Based on the molecular phylogeny and on niche overlap analyses, we uncovered strong evidence to support the idea that ecologically similar species are not necessarily sister species. The correlation analysis for genetic distance and niche overlap was not significant (P > 0.05). In clades with taxonomic conflicts, we only identified Profundulus oaxacae as a geographically and ecologically distinct group from P. punctatus. All the evidence considered leads us to propose that Profundulidae do not show evidence of niche conservatism and that there are reasons to consider P. oaxacae as a valid species. Our study suggests that niche divergence is a driving evolutionary force that caused the diversification and speciation processes of the Profundulidae, along with the geological and climatic events that promoted the expansion or contraction of suitable environments.
深渊科是一个小型鱼类群，分布于墨西哥南部和洪都拉斯之间，在它们出现的流域中，它们通常是高海拔地区唯一的鱼类代表。我们使用不同的方法和从生态位模型中提取的指标来描述它们的生态位，并重新检查最近发表的该科分子系统发育的系统发育关系，以更好地了解其生物地理和进化历史。我们从生态位保守主义的角度评估了这两条证据线，为讨论该群体分布和进化背后的过程假设奠定了基础。在物种组成不明确的鱼类进化枝中，我们检查了生态位分类是否可以提供信息，以便在地理和生态上区分与任何不同有效物种假设一致的群体。生态位的特征是使用不同参数的最大熵算法以及存在于最相关环境覆盖的主要成分上的投影来进行的，并且在环境空间和地理投影的空间中使用两个指数（D 和 I）来计算生态位比较。使用分子数据，使用*BEAST 方法生成了物种树。使用年龄重叠相关性检验计算这些数据的比较。基于分子系统发育和生态位重叠分析，我们有强有力的证据支持这样一种观点，即生态相似的物种不一定是姐妹种。遗传距离和生态位重叠的相关分析不显著（P>0.05）。在具有分类冲突的进化枝中，我们仅将奥萨卡深渊鱼（Profundulus oaxacae）鉴定为与 P. punctatus 在地理和生态上明显不同的群体。所有考虑的证据都使我们提出深渊科没有表现出生态位保守主义的证据，并且有理由将 P. oaxacae 视为一个有效物种。我们的研究表明，生态位分化是导致深渊科多样化和物种形成过程的驱动进化力量，以及促进适宜环境扩张或收缩的地质和气候事件。
