A paradigm shift in our view of species drives current trends in biological classification
A paradigm shift in our view of species drives current trends in biological classification
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DOI：
10.1111/brv.12676
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发表时间：
2020-12-23
影响因子：
10
通讯作者：
De la Riva, Ignacio
中科院分区：
文献类型：
--
作者：
Padial, Jose M.;De la Riva, Ignacio
近年来，对物种分类变化的不满有所增加。许多这些变化被认为是武断的，源于不合理的概念和方法基础，或者导致物种比过去认识到的物种不那么明显。我们认为，目前物种分类的趋势是一种范式转变的结果，即系统学和群体遗传学已经趋同，并将物种视为形成生命之树分支的系统发育谱系。物种划分现在包括确定哪个种群属于哪个单独的系统发育谱系。这需要对谱系分裂和分化的过程进行推断，我们只能通过偶然的证据和假设来部分地了解这一过程，而这些证据和假设本身也会遭到驳斥。这种方法并非没有问题，因为水平基因转移、基因渗入、杂交、不正确的假设、抽样和方法偏差可能会误导对系统发育谱系的推断。通过识别姐妹关系和模糊或模仿系统发育的过程，要求提高精度，这一方面触发了明确处理这些过程的方法的发展，另一方面，增加了推断/测试这些过程所必需的地理和特征数据采样。尽管我们的分辨能力增强了，但对于许多分类群和地区来说，我们对姐妹关系的认识——我们称之为物种分辨能力——仍然很差，这就影响了物种的界限，也影响了物种之间的差异程度。我们将这种概念转变归因于我们正在目睹的亚种到物种的崛起或它们的完全拒绝的三名命名法的消亡；如果亚种被发现与系统发育谱系相对应，则被提升为种，而如果它们反映了连续或非遗传变异的任意划分，则被拒绝作为捏造的分类群。如果保护策略以分类群为基础，则应强调种，减少亚种的使用，以避免保留连续变异的任意分区；通过关注产生生态系统恢复力和多样性的生物过程，而不是通过正式命名任何类型的可诊断单元，可以最好地保护局部变异。由于许多双名法仍然是指物种的复合体而不是单个物种，许多物种已被发现但尚未命名，地理采样很少，基因谱系被误认为是物种，许多物种限制仍未得到检验，许多群体和地区缺乏足够的物种分辨率，我们在解决这些问题时无法避免频繁的分类变化。变化不仅会影响到被忽视的分类群或地区，也会影响到分类研究沉寂数十年、旧分类被视为理所当然的热门分类群和地区。
Discontent about changes in species classifications has grown in recent years. Many of these changes are seen as arbitrary, stemming from unjustified conceptual and methodological grounds, or leading to species that are less distinct than those recognised in the past. We argue that current trends in species classification are the result of a paradigm shift toward which systematics and population genetics have converged and that regards species as the phylogenetic lineages that form the branches of the Tree of Life. Species delimitation now consists of determining which populations belong to which individual phylogenetic lineage. This requires inferences on the process of lineage splitting and divergence, a process to which we have only partial access through incidental evidence and assumptions that are themselves subject to refutation. This approach is not free of problems, as horizontal gene transfer, introgression, hybridisation, incorrect assumptions, sampling and methodological biases can mislead inferences of phylogenetic lineages. Increasing precision is demanded through the identification of both sister relationships and processes blurring or mimicking phylogeny, which has triggered, on the one hand, the development of methods that explicitly address such processes and, on the other hand, an increase in geographical and character data sampling necessary to infer/test such processes. Although our resolving power has increased, our knowledge of sister relationships - what we designate as species resolution - remains poor for many taxa and areas, which biases species limits and perceptions about how divergent species are or ought to be. We attribute to this conceptual shift the demise of trinominal nomenclature we are witnessing with the rise of subspecies to species or their rejection altogether; subspecies are raised to species if they are found to correspond to phylogenetic lineages, while they are rejected as fabricated taxa if they reflect arbitrary partitions of continuous or non-hereditary variation. Conservation strategies, if based on taxa, should emphasise species and reduce the use of subspecies to avoid preserving arbitrary partitions of continuous variation; local variation is best preserved by focusing on biological processes generating ecosystem resilience and diversity rather than by formally naming diagnosable units of any kind. Since many binomials still designate complexes of species rather than individual species, many species have been discovered but not named, geographical sampling is sparse, gene lineages have been mistaken for species, plenty of species limits remain untested, and many groups and areas lack adequate species resolution, we cannot avoid frequent changes to classifications as we address these problems. Changes will not only affect neglected taxa or areas, but also popular ones and regions where taxonomic research remained dormant for decades and old classifications were taken for granted.