Data from: How scientists perceive the evolutionary origin of human traits: results of a survey study

Various hypotheses have been proposed for why the traits distinguishing humans from other primates originally evolved, and any given trait may have been explained both as an adaptation to different environments and as a result of demands from social organization or sexual selection. To find out how popular the different explanations are among scientists, we carried out an online survey among authors of recent scientific papers in journals covering relevant fields of science (palaeoanthropology, palaeontology, ecology, evolution, human biology). Some of the hypotheses were clearly more popular among the 1266 respondents than others, but none was universally accepted or rejected. Even the most popular of the hypotheses were assessed “very likely” by <50 % of the respondents, but many traits had 1–3 hypotheses that were found at least moderately likely by >70 % of the respondents. An ordination of the hypotheses identified two strong gradients. Along one gradient, the hypotheses were sorted by their popularity, measured by the average credibility score given by the respondents. The second gradient separated all hypotheses postulating adaptation to swimming or diving into their own group. The average credibility scores given for different subgroups of the hypotheses were not related to respondent’s age or number of publications authored. However, (palaeo)anthropologists were more critical of all hypotheses, and much more critical of the water-related ones, than were respondents representing other fields of expertise. Although most respondents did not find the water-related hypotheses likely, only a small minority found them unscientific. The most popular hypotheses were based on inherent drivers, i.e. they assumed the evolution of a trait to have been triggered by the prior emergence of another human-specific behavioural or morphological trait, but opinions differed as to which of the traits came first.

学界已针对人类区别于其他灵长类的特征最初的演化动因提出诸多假说，而任一特征均可同时被解释为对不同环境的适应，或是社会组织需求或性选择的结果。为探明不同解释在科研人员中的认可度，我们针对近期发表于相关领域期刊（古人类学、古生物学、生态学、进化生物学、人类生物学）的论文作者开展了一项线上调查。在1266名受访者中，部分假说的认可度显著高于其余假说，但尚无任何假说获得全体受访者的一致认可或全盘否定。即便最受认可的假说，也仅有不到50%的受访者将其评定为‘极有可能’；但针对多数特征，有1至3种假说获得了超过70%的受访者认定为‘至少中度可信’。对假说进行排序分析后，发现存在两个显著的梯度维度。其中一个维度依据假说的认可度排序，该认可度以受访者给出的平均可信度得分衡量。第二个维度则将所有假定适应游泳或潜水行为的假说归为独立类别。不同假说子类的平均可信度得分，与受访者的年龄及已发表论文数量均无关联。然而，相较于其他专业领域的受访者，（古）人类学家对所有假说的批判态度更强，对与水相关假说的批判尤为严厉。尽管多数受访者认为与水相关的假说可信度不高，但仅有极少数受访者认为这些假说不具备科学性。最受认可的假说均基于内在驱动因素，即假定某一特征的演化由另一项人类特有的行为或形态特征的先期出现所触发，但学界对于何者率先出现存在分歧。