Macroecological correlates of Darwinian shortfalls across terrestrial vertebrates

Most described species have not been explicitly included in phylogenetic
trees—a problem named the Darwinian shortfall—due to a lack of molecular
and/or morphological data, thus hampering the explicit incorporation of
evolution into large-scale biodiversity analyses. We investigate potential
drivers of the Darwinian shortfall in tetrapods, a group where at least
one-third of described species still lack phylogenetic data, thus
necessitating the imputation of their evolutionary relationships in
fully-sampled phylogenies. We show that the number of preserved specimens
in scientific collections is the main driver of phylogenetic knowledge
accumulation, highlighting the major role of biological collections in
unveiling novel biodiversity data and the importance of continued sampling
efforts to reduce knowledge gaps. Additionally, large-bodied and
wide-ranged species, as well as terrestrial and aquatic amphibians and
reptiles, are phylogenetically better known. Therefore, future efforts
should prioritize phylogenetic research on organisms that are
narrow-ranged, small-bodied, and underrepresented in scientific
collections, such as fossorial species. Addressing the Darwinian shortfall
will be imperative for advancing our understanding of evolutionary drivers
shaping biodiversity patterns and implementing comprehensive conservation
strategies.

目前，绝大多数已描述物种尚未被明确纳入系统发育树（phylogenetic trees），这一问题被称为达尔文缺失（Darwinian shortfall），其根源在于分子和/或形态学数据的匮乏，进而阻碍了将演化过程明确纳入大规模生物多样性分析之中。
本研究针对四足动物（tetrapods）类群的达尔文缺失问题的潜在驱动因素展开探究——该类群中仍有至少三分之一的已描述物种缺乏系统发育数据，因此在构建全采样系统发育树时，需要对这些物种的演化关系进行推演补全。
研究结果显示，科学馆藏中的标本保存量是系统发育认知积累的核心驱动因素，这凸显了生物馆藏在揭示全新生物多样性数据中的关键作用，以及持续开展采样工作以填补认知空白的重要性。
此外，体型较大、分布范围广泛的物种，以及陆生与水生的两栖类和爬行类，其系统发育认知程度更高。
因此，未来的研究应优先针对分布范围狭窄、体型较小且在科学馆藏中代表性不足的类群开展系统发育研究，例如穴居物种。
解决达尔文缺失问题，对于深化我们对塑造生物多样性格局的演化驱动因子的认知，以及落实综合保护策略而言，均势在必行。