Refer back to Chapter 4 of your textbook, in the second paragraph in the section on mammals. Establish your clear understanding of Rechtschaffen’s statement, “If sleep does not serve an absolutely vital function then it is the biggest mistake the evolutionary process has ever made.” In your own words, explain what he meant.Please write 100-300 words. Remember not to plagiarize. There are no wrong answers so you do not need to check with me to find out if you are correct. I want to know your understanding of his statement. Figure 4.9 Bathow can we resist the question, "Why is sleep sovital?" Let's further investigate animal sleep andget some answers.Although they live and sleep in the water,whales, seals, and dolphins are mammals and somust breathe in the air. If they fell fully asleepunderwater, they would drown, so like somebirds, only half of their brain sleeps at a time.When one hemisphere is sleeping, the otherhemisphere guides the animal to the surface andactivates the body to take a breath. The visual sys-tem of the awake hemisphere is vigilant for dangerand stays connected to other animals in its group,such as companions or offspring. These elaborateevolutionary adaptations suggest that sleep mustprovide a crucial function, since sleep does notmake it to the bargaining table when evolutionarypressure looks for behaviors to remove. At firstFigure 4.10 Sea ottersAnimals: Mammals 67Ready to Move On?Before moving on, establishthat you have a clear under-standing of Rechtschaffen'sstatement, "If sleep does not serve an abso-lutely vital function, then it is the biggestmistake the evolutionary process has evermade." In your own words, explain whathe meant.blush, it seems it would be easier to evolve to notsleep than to evolve the mechanisms necessaryto sleep while swimming. In other words, sleepis indispensable!Getting back to unihemispheric sleep in aquaticmammals, there are exceptions: seals have bihemi-spheric sleep underwater (they hold their breath)and sperm whales sleep with both hemispherestoo, seemingly dangling in the water, tail down,until they awaken to swim to the surface to take abreath (figure 4.11).Dolphins and some whales do not show obvi-ous signs of REM sleep, but scientists speculatethat they may experience transient REM sleep orREM brain activity in deeper structures than thecortex. This motivation to not rule out dolphin andwhale REM sleep is partially due to observed mus-cle twitching, penile erections, and eyelid move-ments during dolphin sleep. These behaviors areassociated with REM sleep in land mammals butalso occur during waking states, so REM sleep indolphins remains an area of active research. Dol-phins are so highly evolved that maybe we will seethey have a unique form for REM that providesadditional survival benefits beyond those given tous humans during REM sleep.Fur seals do clearly have REM sleep, but theyadd a unique variation to its predictability. On land,the fur seal sleeps with both hemispheres at onceand goes through REM and NREM stages, similarto most mammals (figure 4.12). However, when afur seal sleeps in the water, its sleep is similar to ccccccc'Olelo Hawai'i(Language of Hawai'i)'Iwa is Hawaiian for "frigatebird" (figure 4.7).can stay awake for two weeks at a time during itsmigratory period and apparently not suffer theusual deleterious consequences of sleep depriva-tion. During these phases, the bird also remainscapable of proficiently responding to stimuli. TheUS military, with its history of pressuring troops touse various forms of stimulants such as amphet-amines (with deadly consequences), is highlymotivated to determine a way to keep people suchas pilots awake for long stretches at a time withoutnot compromising their judgment or damagingtheir health. At this point, the science suggests it isnot possible. Let's hope for the sake of the troops,their families, and the world community that thereare also researchers actively investigating revolu-tionary and innovative solutions to minimize theneed to put people in harm's way.MammalsImagine swimming through the ocean with halfof your brain asleep, or catching z's while dan-gling like a ripe mango from a tree (figures 4.8and 4.9). The unihemispheric sleep of dolphinsallows them to swim and communicate-duringsleep-with other dolphins. Up in the trees, bats,with their unique wing structure, are unable tocreate the rapid vertical takeoff mastered by birds.The best way for a sleeping bat to escape a hungryraccoon lumbering toward its roost is for the batto drop from the tree and take flight midair. In thesea, dozens of sea otters come together and wrapthemselves in seaweed, creating a sea otter raftfor safety in numbers and to keep from drifting* E. Mignot, "Why We Sleep: The Temporal Organization ofRecovery," PLoS Biology 6, no. 4 (April 2008), https://doi.org/10.1371/journal.pbio.0060106.Figure 4.7 Frigate birdaway while snoozing. Occasionally, they even holdhands (figure 4.10). In open grassy areas, cows,horses, zebras, and elephants can sleep standingup, able to quickly flee if attacked. They have a"stay apparatus" that allows them to essentiallylock their legs, minimizing muscular effort toremain standing. At times, these big mammalsalso lie down to sleep in order to complete theirsleep architecture.Noticing the range of adaptations and behav-iors that make it possible for animals to sleep andsurvive, we see that sleep has persisted even inthe face of environments where it seems it wouldhave been simpler to just eliminate it from themix. As Alan Rechtschaffen, a sleep science trail-blazer, has said, "If sleep does not serve an abso-lutely vital function, then it is the biggest mistakethe evolutionary process has ever made."* ThenFigure 4.8 Dolphins

In the given message, Alan Rechtschaffen's assertion is featured: "On the off chance that rest…

Answered: blish nder- Ffen's bso- ggest ever what

11th Edition

ISBN:9780134580999

Author:Elaine N. Marieb, Katja N. Hoehn

Publisher:Elaine N. Marieb, Katja N. Hoehn

Chapter1: The Human Body: An Orientation

Section: Chapter Questions

Problem 1RQ: The correct sequence of levels forming the structural hierarchy is A. (a) organ, organ system,...