Adaptive Evolution of the Ventral Scale Microornamentations among Three Snake Species

Research on the ecological effect of microronamentations on the scale surface in reptiles has been carried out over the past few decades.It is found that the microornamentation pattern in reptiles is related to their habitats.This study examined the wettability on scale surface,as well as the differences in microornamentation on ventral scales from the mid-body region in three snake species,Hypsiscopus plumbea(aquatic),Oocatochus rufodorsata(semi-aquatic) and Elaphe carinata(terricolous).Moreover,the scale specimens were metallized and analyzed using scanning electron microscopy.Our results showed that there are microornamentations on the ventral scale surfaces of the tested species,which showed interspecific differences.To be specific,the aquatic snake shows the narrow,fine and regular denticulations which are connected to reduce friction and dirt shedding.By contrast,the terrestrial snake acquired the wider and shorter denticulation which would render more friction during locomotion but it shows greater water resistance to improve the capacity of dirt shedding and compensate for the disadvantage of short and wide denticulations.Additionally,the denticulation characteristics of the semi-aquatic snake fell in between those of aquatic and terrestrial snakes.Therefore,it is deduced in this study that the ventral scale microornamentations in snakes contribute to ecological adaptation to their preferential microhabitats.

自我牺牲型领导对员工工作努力的双刃剑效应:领导认同与领导虚伪的作用

一直以来,自我牺牲型领导都因其所展现出的自我牺牲行为而备受推崇。现有研究普遍认为,自我牺牲型领导在调动员工工作积极性、感召员工努力工作等方面均发挥了正面作用。然而,有学者提出,自我牺牲型领导有时并不能对员工产生正面激励作用。为回应上述研究分歧,本研究提出自我牺牲型领导对员工工作努力具有双刃剑影响效应,且这种效应取决于员工对自我牺牲型领导的印象管理归因。对365份领导-员工两时点配对数据进行回归分析后发现:当员工的印象管理归因较高时,自我牺牲型领导使员工感知到领导虚伪,从而降低员工工作努力。当员工的印象管理归因较低时,自我牺牲型领导激发员工对领导的认同,从而提升员工工作努力水平。通过归因理论视角,揭示了自我牺牲型领导所具有的两面性,拓宽了自我牺牲型领导对员工工作努力的影响机制研究,同时为组织提升员工工作努力水平提供了启示。