首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
The opposite of adaptive divergence is an interesting and fairly common expression of evolution. Whereas related groups of organ
The opposite of adaptive divergence is an interesting and fairly common expression of evolution. Whereas related groups of organ
admin
2011-03-26
68
问题
The opposite of adaptive divergence is an interesting and fairly common expression of evolution. Whereas related groups of organisms take on widely different characters in becoming adapted to unlike environments in the case of adaptive divergence. We find that Unrelated groups of organisms exhibit adaptive convergence when they spot similar modes of life or become suited for special sorts of environments. For example, invertebrate marine animals living firmly attached to the sea bottom or to some foreign object tend to develop a sub- cylindrical or conical form. This is illustrated by coral individuals, by many sponges, and even by the diminutive tubes of bryozoans. Adaptive convergence in taking this coral-like form is shown by some brachiopods and pelecypods that grew in fixed position. More readily appreciated is the streamlined fitness of most fishes for moving swiftly through water; they have no neck, the contour of the body is smoothly curved so as to give minimum resistance, and the chief propelling organ is a powerful tail fin. The fact that some fossil reptiles (ichthyosaurs) and modem mammals (whales, dolphins) are wholly fishlike in form is an expression of adaptive convergence, for these air-breathing reptiles and mammals, which are highly efficient swimmers, are not closely related to fishes. Unrelated or distantly related organisms that develop similarity of form are sometimes designated as homeomorphs (having same form).
Adaptive convergence and adaptive divergence are ______.
选项
A、manifestations of evolution
B、biological phenomena
C、ways in which plants and animals adjust to a common environment
D、demonstrated by brachiopods and pelecypods
答案
A
解析
适应性趋同现象和适应性趋异现象是进化的表现形式。根据第一句话,与适应性趋异现象相反的趋同现象是一种有趣而又相当常见的、与进化有关的表现形式。由此可以推断,趋异现象也是一种进化的表现形式。
转载请注明原文地址:https://kaotiyun.com/show/NqBO777K
0
考博英语
相关试题推荐
WoulditbepossibletobringthedayofyourmeetingwithMr.Jacksonforwardbyadayorso?
Questions29-40•Readtheinformationaboutthecommunicationofinformationinbusiness.•Choosethecorrectwordtofi
•Lookatthegraphs(A-H)below,whichshowhoweightdifferentcompaniesrecruitedstaffoverfouryears.•Whichcompanydoe
•Headtilenewspaperarticlebelowaboutnewallianceinthepackagingindustry.•Choosethebestwordtofillineachgap,fr
•Lookattheadvertisementbelow.Itshowsreportsofferedbyacompany.•Forquestions6-10,decidewhichreport(A-H)would
Thesafetyteamiscarryingoutchecksinthisarea.Accesswithoutapermitisdenieduntilfurthernotice.
Someresearchersfeelthatcertainpeoplehavenervoussystemsparticularly______tohot,drywinds.Theyarewhatwecallweathe
Itwastheir______decisiontoleavetheircountry,andasaresult,theylosttheircitizenship.
Scientistsclaimthatairpollutioncausesadeclineintheworld’saverageairtemperature.Inordertoprovethattheory,eco
Inthesimplestterms,amarketistheplacewheresellermeetsbuyertoexchangeproductsformoney.Traditionalmarketsstill
随机试题
水平战略联盟
女,42岁,右腰部疼痛剧烈难忍,伴恶心、呕吐1天,疼痛放射至同侧下腹、会阴及大腿内侧,尿常规检查:RBC10~15/HP,血常规检查:WBC8.2×109/L,N75%最可能的诊断是
十二指肠球部溃疡表现为胆道蛔虫病表现为
张某、王某和刘某签订合伙协议,设立合伙企业,约定张某于企业成立之日起3个月内出资10万元,企业成立后,张某拒绝出资,以下说法正确的是:()
经济法律关系的( )是指经济法律关系主体的权利义务共同指向的事物。
背景资料:某公司承建一项地铁车站土建工程,车站长236m,标准段宽19.6m,底板埋深16.2m,地下水位标高为13.5m,车站为地下二层三跨岛式结构,采用明挖法施工,围护结构为地下连续墙,内支撑第一道为钢筋混凝土支撑,其余为800mm钢管支撑,基坑内设
某新建项目,建设期为3年,共向银行贷款1800万元。贷款分别为:第1年400万元,第2年800万元,第3年600万元。年利率为5%,则建设期利息为()万元。
SQL支持集合的并运算,在VisualFoxPro中SQL并运算的运算符是
(Eventhough)he(hadbeenstudying)Englishforthreeyears(before)hecametoEngland,itisstilldifficultforhimtomake
(1)WhenIwasayounggirllivinginIreland,Iwasalwayspleasedwhenitrained,becausethatmeantIcouldgotreasurehunti
最新回复
(
0
)