2022新概念英语优美背诵短文.docx

2022新概念英语优美背诵短文新概念英语美丽背诵短文引导语：说起睡觉信任大家都很熟识那么大家知道睡眠也是有进化的么?下面就让我通过一则新概念英语美丽短文告知你关于睡眠的进化。EvolutionofSleep睡眠的进化Sleepisveryancient.Intheelectroencephalographicsenseweshareitwithalltheprimatesandalmostalltheothermammalsandbirds:itmayextendbackasfarasthereptiles.睡眠自古就有。从脑电图上看我们人类和全部灵长目动物以及几乎全部的哺乳动物和鸟类都一样须要睡眠;甚至爬行类动物也有睡眠。Thereissomeevidencethatthetwotypesofsleepdreaminganddreamlessdependonthelife-styleoftheanimalandthatpredatorsarestatisticallymuchmorelikelytodreamthanpreywhichareinturnmuchmorelikelytoexperiencedreamlesssleep.Indreamsleeptheanimalispowerfullyimmobilizedandremarkablyunresponsivetoexternalstimuli.Dreamlesssleepismuchshallowerandwehaveallwitnessedcatsordogscockingtheirearstoasoundwhenapparentlyfastasleep.有证据显示有梦睡眠和无梦睡眠这两种类型的睡眠取决于该动物的生活方式。从统计上看食肉动物比被捕食动物有更多的有梦睡眠而被捕食动物更多地无梦睡眠。动物在有梦睡眠时被有效地解除动作实力并且对外界刺激缺乏反应。无梦睡眠则要浅得多。我们都看到过猫和狗在明显的酣睡中有一点响动耳朵就会竖起来。Thefactthatdeepdreamsleepisrareamongpreytodayseemsclearlytobeaproductofnaturalselectionanditmakessensethattodaywhensleepishighlyevolvedthestupidanimalsarelessfrequentlyimmobilizedbydeepsleepthanthesmartones.Butwhyshouldtheysleepdeeplyatall?Whyshouldastateofsuchdeepimmobilizationeverhaveevolved?Perhapsoneusefulhintabouttheoriginalfunctionofsleepistobefoundinthefactthatdolphinsandwhalesandaquaticmammalsingeneralseemtosleepverylittle.Thereisbyandlargenoplacetohideintheocean.被捕食动物很少有深度的有梦睡眠这看来明显是自然选择的结果。而且这一点是有道理的：当睡眠高度进化以后愚笨的动物比聪慧的动物更少在深度睡眠状态下丢失动作实力。但是动物为什么要进入深度睡眠呢?为什么这样的无动作状态也会进化出来呢?海豚、鲸鱼以及水生哺乳动物睡眠都极少这一事实可以给睡眠的根本功能供应有用的线索。海洋中是没有藏身之处的。Coulditbethatratherthanincreasingananimal'svulnerabilitythefunctionofsleepistodecreaseit?WilseWebboftheUniversityof