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roaming文件夾是干嘛的 roaming文件夾( 三 )

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▲ 鏈接：
https://www.science.org/doi/10.1126/science.abj7478
▲ 摘要
眾所周知 ， 草原食草動(dòng)物通過消耗可能易燃的物質(zhì) ， 在限制野火方面發(fā)揮著作用 。作者提出的證據(jù)表明 ， 食草動(dòng)物-火的相互作用在過去影響了全球范圍內(nèi)的火 。他們將晚第四紀(jì)大陸層面巨型草食動(dòng)物滅絕的嚴(yán)重程度與草食生物群落沉積木炭數(shù)據(jù)計(jì)算出的古火活動(dòng)變化進(jìn)行了比較 。
不同大陸的物種滅絕程度不同 ， 這種模式反映在火災(zāi)活動(dòng)的變化上 。在大型食草動(dòng)物滅絕最嚴(yán)重的地方（南美洲）和滅絕發(fā)生最少的地方（非洲） ， 火災(zāi)頻率增加最多 。大型食草動(dòng)物在第四紀(jì)的消失極大地改變了全球的野火狀況 。
▲ 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
大閃蝶飛行的適應(yīng)性進(jìn)化
▲ 作者：CAMILLE LE ROY, DARIO AMADORISAMUEL CHARBERETJAAP WINDTFLORIAN T. MUIJRES , VIOLAINE LLAURENS AND VINCENT DEBAT
▲ 鏈接：
https://www.science.org/doi/10.1126/science.abh2620
▲ 摘要
森林通常是擁擠和復(fù)雜的 ， 給在其中飛行的物種帶來了無數(shù)和各種各樣的挑戰(zhàn) 。作者觀察了亞馬遜大閃蝶群體 ， 發(fā)現(xiàn)在形態(tài)和行為方面 ， 占據(jù)冠層的物種與占據(jù)林下植被的物種存在差異 。
那些進(jìn)化到占據(jù)冠層的物種 ， 由于翅膀形狀和飛行行為的結(jié)合 ， 它們的滑翔能力有所提高 。這些特征的組合在不同的物種中是不同的 ， 甚至在這個(gè)單一的屬中 ， 這表明沒有一條路徑導(dǎo)致了這片森林的殖民 。
▲ 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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