版權(quán)說明：本文檔由用戶提供并上傳，收益歸屬內(nèi)容提供方，若內(nèi)容存在侵權(quán)，請(qǐng)進(jìn)行舉報(bào)或認(rèn)領(lǐng)
文檔簡介
1、GWD_RC_改版大全制作者:Hamiton@CDGWDTN1..........................................................2GWDTN2..........................................................8GWDTN3........................................................16G
2、WDTN4........................................................24GWDTN5........................................................31GWDTN6........................................................38GWDTN7.......................
3、.................................44GWDTN8........................................................53GWDTN9........................................................60GWDTN10..................................................
4、....68GWDTN11......................................................76GWDTN13......................................................91GWDTN14....................................................100GWDTN15...................
5、.................................105GWDTN16....................................................111GWDTN17....................................................118GWDTN18....................................................1
6、22GWDTN19....................................................129GWDTN20....................................................135GWDTN21....................................................144GWDTN22.........................
7、...........................150GWDTN23....................................................156GWDTN24....................................................161GWD1Q9toQ12:Overthelast150yearslargestretchesofsalmonhabitathavebe
8、eneliminatedbyhumanactivity:mininglivestockgrazingtimberharvestingagricultureaswellasrecreationalurbandevelopment.Thenumericaleffectisobvious:therearefewersalmonindegradedregionsthaninpristineoneshoweverhabitatlossalsoha
9、sthepotentialtoreducegeicdiversity.Thisismostevidentincaseswhereitresultsintheextinctionofentiresalmonpopulations.Indeedmostanalystsbelievethatsomekindofenvironmentaldegradationunderliesthedemiseofmanyextinctsalmonpopula
10、tions.Althoughsomerivershavebeenrecolonizedtheuniquegenesoftheiginalpopulationshavebeenlost.Largescaledisturbancesinonelocalealsohavethepotentialtoalterthegeicstructureofpopulationsinneighbingareasevenifthoseareashavepri
11、stinehabitats.WhyAlthoughthehominginstinctofsalmontotheirnatalstreamisstrongafractionofthefishreturningfromthesea(rarelymethan15percent)strayspawninnearbystreams.Lowlevelsofstrayingarecrucialsincetheprocessprovidesasourc
12、eofnovelgenesamechanismbywhichalocationcanberepopulatedshouldthefishtheredisappear.Yethighratesofstrayingcanbeproblematicbecausemisdirectedfishmayinterbreedwiththeexistingstocktosuchadegreethatanylocaladaptationsthatarep
13、resentbecomediluted.Strayingratesremainrelativelylowwhenenvironmentalconditionsarestablebutcanincreasedramaticallywhenstreamssufferseveredisturbance.The1980volcaniceruptionofMountSaintHelensfexamplesentmuddebrisintosever
14、altributariesoftheColumbiaRiver.Fthenextcoupleofyearssteelheadtrout(aspeciesincludedamongthesalmonids)returningfromtheseatospawnwerefcedtofindalternativestreams.Asaconsequencetheirratesofstrayinginitially16percentrosetom
15、ethan40percentoverall.AlthoughnoonehasquantifiedchangesintherateofstrayingasaresultofthedisturbancescausedbyhumansthereisnoreasontosuspectthattheeffectwouldbequalitativelydifferentthanwhatwasseenintheaftermathoftheMountS
16、aintHelenseruption.Suchadramaticincreaseinstrayingfromdamagedareastomepristinestreamsresultsinsubstantialgeneflowwhichcaninturnlowertheoverallfitnessofsubsequentgenerations.GWD1Q9:TheprimarypurposeofthepassageistoA.argue
17、againstaconventionalexplanationftheextinctionofcertainsalmonpopulationssuggestanalternativeB.crectacommonmisunderstingaboutthebehaviofsalmoninresponsetoenvironmentaldegradationcausedbyhumanactivityC.comparetheeffectsofhu
18、manactivityonsalmonpopulationswiththeeffectsofnaturaldisturbancesonsalmonpopulationsD.differentiatetheparticulareffectsofvarioushumanactivitiesonsalmonhabitatsE.describehowenvironmentaldegradationcancausechangesinsalmonp
19、opulationsthatextendbeyondanumericalreductionGWD1Q10:ItcanbeinferredfromthepassagethattheoccasionalfailureofsomesalmontoreturntotheirnatalstreamsindertospawnprovidesamechanismbywhichA.pristinestreamsthatarenearpollutedst
20、reamsbecomepollutedthemselvesB.theparticularadaptationsofapollutedstream’ssalmonpopulationcanbepreservedwithoutdilutionC.thenumberofsalmoninpristinehabitatsdecreasesrelativetothenumberinpollutedstreamsD.anenvironmentally
21、degradedstreamcouldberecolonizedbynewsalmonpopulationsshouldthestreamrecoverE.theextinctionofthesalmonpopulationsthatspawninpollutedstreamsisacceleratedGWD1Q11:Accdingtothepassagehumanactivityhashadwhichofthefollowingeff
22、ectsonsalmonpopulationsA.AnincreaseinthesizeofsalmonpopulationsinsomepreviouslypollutedriversB.AdeclineinthenumberofsalmoninsomeriversC.AdecreaseinthenumberstrayingsalmoninsomeriversD.Adecreaseinthegeneflowbetweensalmonp
溫馨提示
- 1. 本站所有資源如無特殊說明，都需要本地電腦安裝OFFICE2007和PDF閱讀器。圖紙軟件為CAD,CAXA,PROE,UG,SolidWorks等.壓縮文件請(qǐng)下載最新的WinRAR軟件解壓。
- 2. 本站的文檔不包含任何第三方提供的附件圖紙等，如果需要附件，請(qǐng)聯(lián)系上傳者。文件的所有權(quán)益歸上傳用戶所有。
- 3. 本站RAR壓縮包中若帶圖紙，網(wǎng)頁內(nèi)容里面會(huì)有圖紙預(yù)覽，若沒有圖紙預(yù)覽就沒有圖紙。
- 4. 未經(jīng)權(quán)益所有人同意不得將文件中的內(nèi)容挪作商業(yè)或盈利用途。
- 5. 眾賞文庫僅提供信息存儲(chǔ)空間，僅對(duì)用戶上傳內(nèi)容的表現(xiàn)方式做保護(hù)處理，對(duì)用戶上傳分享的文檔內(nèi)容本身不做任何修改或編輯，并不能對(duì)任何下載內(nèi)容負(fù)責(zé)。
- 6. 下載文件中如有侵權(quán)或不適當(dāng)內(nèi)容，請(qǐng)與我們聯(lián)系，我們立即糾正。
- 7. 本站不保證下載資源的準(zhǔn)確性、安全性和完整性, 同時(shí)也不承擔(dān)用戶因使用這些下載資源對(duì)自己和他人造成任何形式的傷害或損失。
評(píng)論
0/150
提交評(píng)論