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▲ 链接：
https://www.science.org/doi/10.1126/science.abj7478
▲ 摘要
众所周知 ， 草原食草动物通过消耗可能易燃的物质 ， 在限制野火方面发挥着作用 。作者提出的证据表明 ， 食草动物-火的相互作用在过去影响了全球范围内的火 。他们将晚第四纪大陆层面巨型草食动物灭绝的严重程度与草食生物群落沉积木炭数据计算出的古火活动变化进行了比较 。
不同大陆的物种灭绝程度不同 ， 这种模式反映在火灾活动的变化上 。在大型食草动物灭绝最严重的地方（南美洲）和灭绝发生最少的地方（非洲） ， 火灾频率增加最多 。大型食草动物在第四纪的消失极大地改变了全球的野火状况 。
▲ Abstract
Grassland herbivores are known to play a role in limiting wildfires by consuming potentially flammable material. Karp et al. present evidence that that herbivore-fire interactions affected fire on a global scale in the past. They compared the severity of late Quaternary continent-level megaherbivore extinctions with changes in paleofire activity calculated from sedimentary charcoal data from grassy biomes. The extent of extinctions varied between continents, and this pattern was reflected in the changes in fire activity. Fire frequency increased most where the megaherbivore extinctions were greatest (South America) and least where few extinctions occurred (Africa). This loss of large-bodied grazers in the Quaternary drastically altered global fire regimes.
Adaptive evolution of flight in Morpho butterflies
大闪蝶飞行的适应性进化
▲ 作者：CAMILLE LE ROY, DARIO AMADORISAMUEL CHARBERETJAAP WINDTFLORIAN T. MUIJRES , VIOLAINE LLAURENS AND VINCENT DEBAT
▲ 链接：
https://www.science.org/doi/10.1126/science.abh2620
▲ 摘要
森林通常是拥挤和复杂的 ， 给在其中飞行的物种带来了无数和各种各样的挑战 。作者观察了亚马逊大闪蝶群体 ， 发现在形态和行为方面 ， 占据冠层的物种与占据林下植被的物种存在差异 。
那些进化到占据冠层的物种 ， 由于翅膀形状和飞行行为的结合 ， 它们的滑翔能力有所提高 。这些特征的组合在不同的物种中是不同的 ， 甚至在这个单一的属中 ， 这表明没有一条路径导致了这片森林的殖民 。
▲ Abstract
Forests are often crowded and complex, presenting numerous and varied challenges for species flying through them. Le Roy et al. looked at the Amazonian Morpho butterfly group and found differences in both morphological and behavioral perspectives across species that occupy the canopy relative the understory. Species that evolved to occupy the canopy have improved gliding abilities because of a combination of wing shape and flight behavior. The combination of these traits varied across species even within this single genus, which suggests that there was not one route that led to colonization of this part of the forest.
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