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Martin (1968, 1984, 1990) has summarized the evidence for the world-wide
extinction of late Pleistocene megafauna.

In Africa and Asia 15–20 percent of the genera disappeared 80–60,000 years B.P.; in Australia 94 percent were lost from 40–15,000 years B.P.; North and South America
experienced a 70–80 percent loss in the last 15,000 years, with an abrupt(突然的) North American loss of mammoth, mastodon, ground sloth, and such dependent predators and scavengers as the saber toothed cat and (in much of its range) the condor 11,000 years ago. The horse and two subspecies of bison were gone by 9–8,000 years ago. This worldwide pattern correlates suspiciously with the chronology of human colonization leading to Paul Martin's hypothesis that extinction was directly or indirectly due to “overkill” by  exceptionally competent hunter cultures. This model explains the light extinctions in Africa and Asia where modern humankind “grew up,” allowing gradual adaptation to humankind's accumulating proficiency as a superpredator; it explains the abrupt massive losses in Australia and the Americas—the only habitable continents that
were colonized suddenly by advanced stone-aged humans. But the control cases for Martin's “experiment” are the large oceanic islands such as Madagascar and New
Zealand; both were colonized within the last 1000 years, and both suffered a wave of extinctions at this time.

One wonders, if extinction was due to climatic change, why Madagascar extinctions were not coincident with those of Africa 220 miles off its coast, and those of Australia were not coincident with New Zealand extinctions; and why European and Ukrainian mammoths became extinct 13,000 years B.P. while in North America they survived another 2000 years. Previous great extinction waves had affected plants and small animals as well as large animals, but the late Pleistocene extinctions are concentrated on the large gregarious herding, or slow moving, animals—the ideal prey of human hunters. Such large genera are also the animals that are slower growing, have longer gestation periods, require longer periods of maternal care, and live longer. Consequently they were more vulnerable to hunting pressure because reductions in biomass require more time to recover. The theory is bold—some say fanciful.

A counter argument is that there is little direct evidence of hunting; that Paleolithic peoples “probably” relied on plants. But if the fossil record of hunting is “small,” the fossil evidence of gathering is virtually non-existent.

A second counter argument is that there would not have been an incentive to overproduce in excess of immediate needs; that this occurs only in modern exchange
economies. But this argument fails to recognize that in the absence of private property rights, there is no intertemporal incentive to avoid the
kind of waste associated with large kills. What controls the slaughter of domestic cattle is the comparative value of dressed versus live beef. Since no one owned the mammoth, their harvest value (net of hunting cost) contrasted sharply with their zero live procreation value to the individual hunter. A third argument finds it incomprehensible that mere bands of men could have wiped out the great mammoth and two subspecies of bison. It takes a particularly skilled modern rifleman to stop a charging African elephant in time to prevent injury, and extant bison react quickly and violently when they sense danger.   


Such observations may simply tell us that these particular subspecies have survived because they were selected for their successful defensive characteristics. We know nothing of the behavioral properties of extinct species which may have been far more approachable than their surviving relatives. While the African and Indian elephants are both members of the same genus, their fossil similarities fail to inform us that the Indian elephant is docile and easily trained for circus display, while the African elephant is not. No one has successfully domesticated the African zebra; in contrast, the Tarpan horse has been domesticated since ancient times (5000–2500 B.P.). Equus includes horses, asses and zebras—all behaviorally distinct animals.

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猛兽灭绝2
P1：第一段的行文就三句话。(the first sentence) The recent evidence of the bones of M found in the XXX pit 怎样了。。然后不同于一个另一个pit的。第二句说before（之前）the scientist had found that M 死于什么什么原因，什么什么环境。。。第三句说，but the evidence now indicates that...the M 死于一个什么pond.
第二段，开始转折了，说还有许多科学家争论到这些m死的情况。到底是在pond里淹死的，还是死了以后掉进pond里的。然后很多contend。。说如果是掉进pond里死的话，这些骨头就应该藏的更深，然后骨质就应该更酥松什么的。。。然后结论好像是该动物不可能是活活在沼泽中困死的，而是先死之后，其遗迹慢慢陷入沼泽的。
题目：
1、有题问文章的第2句的作用是什么。
答案是：提供了一种关于m死亡的说法，但被第三句反驳掉了。。。

Riff

2.1.3  native species declines
第一段： native species declines, 有人认为是因为nonnative species［nondominant species］ invade了，也有人认为是本地的一些环境改变，像污染之类的才是造成这个原因, 然后给了个例子说某某湖的某鱼在另外一种鱼来invade（侵犯）之前数量已经decline了，原因是人们过度捕捞还有环境污染之类（后面有一道题目问这个例子说明了神马，或者问这个例子的作用是什么来着）。所以是因为本来nonnative species所在的环境不行了，因此nonnative species才长得好，因此nonnative species长得好是consequence不是原因。这段作者没有给出他的point
第二段： 说2个研究的人说，如果是nonnative species造成的，那如果把nonnative species拿掉的话，native species 就不会减少了；如果是本地环境变化造成的，那就算拿掉nonnative species 的话也会减少native species。（有题目问说这2个学者认为下面哪个assumption是正确的，或者问的是同意下面哪个说法） 然后就分析了一个实验还是研究，在本地的草中间引入两种外来的草，大致是说把新物种移走要是老物种数量多了，就是drive model(貌似)，如果把新物种移走老物种数量没咋变就是passenger model，实验的结果是并没有发现本地的那种草被外来物种影响数量下降（这个地方有题，问实验削弱了那个结论，选项里有关于这两个的[后面有题问哪个support什么什么的.选项CD一个是说的passenger type,一个说driver type.答案应该在这两个里面吧.我好像选的是driver type那个,C.不确定,大家到时还要好好读读]）。
题目：
1、说M和T（最后一段做实验的两个人）based on试验数据会justify以下哪个？
我选了一个什么native plant的thrive兴旺will not be impeded（阻止） by外来species
［偶选的也是那个有Thrive（兴旺）的选项］
2、第二句高亮句的作用。
偶选的是nonnative species invade不是造成habitat degradation的原因
3、主旨题：
就是Nonnative的入侵不是造成native species declines的原因，而是native species declines之后的结果

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2.1.4 lepidoptera(鳞翅类，鳞翅目)
A small number of the forest species of lepidoptera (moths(蛾，蛀虫) and butterflies, which exist as caterpillars during most of their life cycle) exhibit regularly recurring patterns(模式) of population growth and decline—such fluctuations in population are known as population cycles. Although many different variables influence population levels, a regular pattern such as a population cycle seems to imply a dominant, driving force.  Identification of that driving force, however, has proved surprisingly elusive(难懂的) despite considerable research. The common approach of studying causes of population cycles by measuring the mortality caused by different agents, such as predatory birds or parasites(食客，寄生虫), has been unproductive in the case of lepidoptera. Moreover, population ecologists’ attempts to alter cycles by changing the caterpillars’ habitat and by reducing caterpillar populations have not succeeded. In short, the evidence implies that these insect populations, if not self-regulating, may at least be regulated by an agent more intimately(紧密地) connected with the insect than are predatory birds or parasites.

Recent work suggests that this agent maybe a virus.  For many years, viral(滤过性毒菌引起的) disease had been reported in declining populations of caterpillars, but population ecologists had usually considered viral disease to have contributed to the decline once it was underway rather than to have initiated(发起) it. There cent work has been made possible by new techniques of molecular biology that allow viral DNA to be detected at low concentrations in the environment.  Nuclear polyhedrosis viruses(多角体病毒) are hypothesized to be the driving force behind population cycles in lepidoptera in part because the viruses themselves follow an infectious cycle in which, if protected from direct sun light, they may remain virulent for many years in the environment, embedded(嵌入) in durable(持久的，耐用的) crystals(晶体) of polyhedrin（多角体蛋白） protein. Once ingested(咽下) by a caterpillar, the crystals dissolve, releasing the virus to infect the insect’s cells. Late in the course of the infection, millions of new virus particles are formed and enclosed in polyhedron(多面体) crystals. These crystals reenter(重新加入，再加入) the environment after the insect dies and decomposes, thus becoming available to infect other caterpillars.

One of the attractions of this hypothesis is its broad applicability. Remarkably, despite significant differences in habitat and behavior, many species of Lepidoptera have population cycles of similar length, between eight and eleven years.  Nuclear polyhedrosis viral infection is one factor these disparate species share.

T-9-20:GWD-13-34:
Which of the following, if true, would most weaken the author’s conclusion in lines 25-30?
A. New research reveals that the number of species of birds and parasites that prey on lepidoptera has dropped significantly in recent years.
B. New experiments in which the habitats of lepidoptera are altered in previously untried ways result in the shortening of lepidoptera population cycles.
C. Recent experiments have revealed that the nuclear polyhedrosis virus is present in a number of predators and parasites of lepidoptera.
D. Differences among the habitats of lepidoptera species make it difficult to assess the effects of weather on lepidoptera population cycles.
E. Viral disease is typically observed in a large proportion of the lepidoptera population.

T-9-21:GWD-13-35:
It can be inferred from the passage that the mortality caused by agents such as predatory birds or parasites was measured in an attempt to
A. develop an explanation for the existence of lepidoptera population cycles
B. identify behavioral factors in Lepidoptera that affect survival rates
C. identify possible methods for controlling lepidoptera population growth
D. provide evidence that Lepidoptera populations are self-regulating
E.   determine the life stages of lepidoptera at which mortality rates are highest

T-9-22:GWD-13-36:
The primary purpose of the passage is to              
A. describe the development of new techniques that may help to determine the driving force behind population cycles in Lepidoptera
B. present evidence that refutes a particular theory about the driving force behind population cycles in Lepidoptera
C. present a hypothesis about the driving force behind population cycles in Lepidoptera
D. describe the fluctuating patterns of population cycles in Lepidoptera
E.    question the idea that a single driving force is behind population cycles in Lepidoptera

T-9-23:GWD-13-37:
According to the passage, before the discovery of new techniques for detecting viral DNA, population ecologists believed that viral diseases
A. were not widely prevalent among insect populations generally
B. affected only the caterpillar life stage of lepidoptera
C. were the driving force behind Lepidoptera population cycles
D. attacked already declining caterpillar populations
E.  infected birds and parasites that prey on various species of lepidoptera

Riff

2.1.5蟾蜍与青蛙
P1:  第一段说两个科学家做蛙类卵的孵化率field study，三个品种的卵拿来照紫外线，第一个品种因为含有某种酶，此酶的activity很活跃因此抵挡紫外线，所以孵化率仍然很高，另外两个的酶activities较低，所以孵化率就不行了，要减少紫外线照射孵化率才会回升。所以证明这个酶跟孵化率有关。 然后说到这个酶还会影响到蛙类的免疫系统。［说青蛙/癞蛤蟆卵对太阳光中的紫外线辐射UV的忍耐度不太一样，有些忍耐力很强，有些则很容易就被kill掉了。三种蛙，有一类H很NB就具有很高的耐受性，另外两种H和B不太行，有了UV就萎了，只有把UV移去才能恢复正常。而且说紫外线照射不仅会影响卵的生长，还会由此影响青蛙的免疫系统］
P2: 说到人类污染导致臭氧减少，紫外线升高，于是很多蛙类的孵化率降低可能是这个原因云云。［讲了这三种eggs的免疫力的问题，说他们的免疫力强的时候也能提高孵化率。但是人类活动不断deplete ozone，使更多紫外线能够到达地球，影响了eggs的免疫力，所以孵化率就降低了。］
题目：
1、主旨
选阐述科学发现那个
2、削弱：一道问下面那个削弱作者观点，这个观点好像是，什么暴露在UV射线下使得青蛙的免疫力下降，因为这样会使得青蛙更容易被一种真菌感染［下列哪个选项能weaken专家关于免疫力的观点?］
原文搜索：dumdumface （已有狗主人确认第一段为原文，但也有狗主人称不是这段，可能是GMAC出变体了，大家自行定夺，建议最好还是看下这段英文~）

Blaustein and his colleagues tested whether or not UV-B could be a factor in lowering the hatching rate of amphibian(两栖动物) eggs. At two field sites, they divided the eggs of each of three amphibian species into three groups (Figure 3.6). The first group developed without any sun filter(过滤器，滤光器). The second group developed under a filter(滤波器，过滤器) that allowed UV-B to pass through. The third group developed under a filter that blocked UV-B from reaching the eggs. For Hyla regilla, the filters had no effect, and hatching success was excellent under all three conditions. For Rana cascadea and Bufo boreas, however, the UV-B blocking filter raised the percentage of eggs hatched from about 60% to close to 80%.

The environmental programs of experimental embryology(胚胎学) were a major part of the discipline when Entwicklungsmechanik was first established. However, it soon became obvious that experimental variables could be better controlled in the laboratory than in the field, and that a scientist could do many more experiments in the laboratory. Thus, field experimentation in embryology dwindled(变小) in the first decades of the twentieth century (see Nyhart 1995). However, with our increasing concern about the environment, this area of developmental biology has become increasingly important. Other recent work in this field will be detailed in Chapter 21.

［主要说科学家在研究是什么因素导致了frog数量减少，好像反正是一种动物。科学家假设是因为frog卵细胞中可以修复DNA的酶活性不够，第二段可是做试验，一共选了三种frog，一种frog的卵在经过阳光照射后DNA损伤不大，对应的这种frog在野外的数量也没有显着减少，两外两种frog的卵经过阳光照射后DNA损失大，因为他们修复DNA的酶的活性不如第一个。第三段说科学家分析frog数量减少也有人类破环臭氧层的关系。但是由于没有以前frog卵受阳光照射强度的资料，现在这个假说也没有被完全证实。
问题：
1、问此文purpose?
我的答案貌似是identify an explanation to some findings
2、还有问如果把那做实验的两组不同frog放在同一地方会咋样,我说这是depend on the extent to shield from the sun
3、有一道题问从文章中可以推测出那两种DNA损失大的frog的什么
我选的是他们的DNA损伤随着光照强度的变化而不同。］

Riff

2.1.6恐龙灭绝（有专题整理）
一屏左右的文章，两段，开头就讲了K-T事件，就是恐龙灭绝的事件（第一句搞亮了）很多scientists认为是小行星撞击造成恐龙灭绝，讲了一堆证据和原因，说这过程涉及i**元素的大量产生（有题，文中说i元素地球上没有，故题目问i元素从哪里来，我选从小行星上来），提到fossils里面有大量动物灭绝的证据。然后有人跳出来说，不对，小行星撞击不是直接原因，撞击后地球发生变化，慢慢产生什么气体还是物质，导致大气不正常，global warm， 然后很多动植物才慢慢死掉。。。［而植物灭亡是从carbon同位素的全面改变得知（有题，我差点选了动物灭亡从fossil中得出。阴险。注意看）］
第二段就说有人研究认为是volcanic eruption造成的，行星撞击造成大量火山喷发，不仅火山灰掩埋了一些动植物，更是由于火山喷发造成大气温度的升高，慢慢使很多动植物死亡。（有题）后面的就不咋记得了。。。。。
题目：
1、第一句高亮的话作用是啥？
选项不咋难选，我选了那个introduce开头的…，大意是介绍了一个现象，并且此后第一段后面的部分在解释它。
2、作者提供了什么evidence来证明有大量古动植物死亡？
对应fossils….那句，就选从化石里发现了很多动植物的残骸。
3、 好像是真正造成大量古动植物灭绝的原因是什么？
我选了是volcanic eruption的一系列mechanism的结果。

Riff

2.1.8  DNA与细菌
讲病菌和antibiotic 的关系。其中谈到了DNA,  讲现在污染很严重， 好像是和什么病菌有关系， 然后导致antibiotic也没用了， 因为， 细菌develop antibiotic resistance（这个确定就是文中的短语），bacteria适应了这些antibiotic。
第二段将有两个人做研究， 他们的方法不是去找到这些病菌（文中用的是spot these bacteria）, 而是去blabbla, 反正就是一种研究办法。然后，讲他们研究病菌的DNA，而这些病菌是从不同的地方采集来的（田间地头、下水道和污水处理厂什么的）。发现在原始无污染的水里(pristine  river)里面某两种物质的含量比从农场工厂（farm）附近收集的水里面含量低。  
题目：
1、有一题是问， 这两人的研究提供什么作用
我选的是好像和第三段的不同地区的data有关。
2、主旨题

Riff

2.1.9 古文物DNA
说科学家们提出一个观点， 现在开始从古文物［化石、骨骼碎片］上面的残留物上分析DNA，来研究这些东西。作者说有科学家不同意，这个方法是有问题的，因为要确定DNA确实是古代的，还是现代物种的是一个关键crucial问题，DNA很有可能是外界接触到的东西的，可能是contamination的或者是人们在处理标本时不小心沾上去的，因此分析这种DNA得出的结论是纯扯淡。（高亮开始）然后有个实验就说在一个什么化石里提取某植物的DNA比对。（高亮结束）有人就说了，要在化石或者骨骼碎片里提取古生物的DNA很难，因为时间久远，而且里面的什么物质会消散什么的。。正常情况下leaf不能保存那么长的时间，因为环境是wet的，所以这个提出来的DNA肯定不是古生物的而是现代物种的。因为里面的一个什么blablabla是现代物种DNA的东西。 文章意思大概就是这样吧，就是这个新方法不太可行（这里有题，问这个例子是怎么反驳科学家的）。作者说这个问题其实很好解决(solution)，因为fossil DNA和modern DNA肯定有很大不同，如果发现跟现有的不一样，那就说明是进化以前的那种DNA。
题目：
1、高亮部分的other scientists认为那个leaves上的DNA很可能被contaminated了是cite了什么证据
我选的含有deposit的选项，不咋确定
2、如果哪个成立会削弱作者的观点(solution)
我选的是fossil DNA和modern DNA没差别
3、主旨题
4、问A科学家关于leaf的问题是如何反驳的？
我选leaf所处的环境决定了它们不可能保存那么长的时间

Riff

2.1.10  beetle 甲虫
第一段上来就将人们越来越多的使用beetle化石fossil（fossilized beetle）来了解古代的温度，作为climate的indicator。
第二段将beetle化石比较其他方法的优点，能够很快的反应出气候的变化并且不会因host受限。最后一句比较其与植物pollen花粉的优点：pollen很容易受到污染(此处有题)。［更靠谱点：相对于不能移动的花草，B有更大的活动自由，因此对于很小的气候波动，他都能及时地作出反应，因此，这也是B作为一个更好的测量标准的原因，因为P不能移动。
问为什么有优势：B可以在短时间内怎样怎样］
第三段讲科学家如何通过b测定气候变化，Scientist具体如何用FB来测气候变化一些方法
题目：
1、主旨题
我选的好像是 xxx（是一个动词，忘了) 一个科学方法which科学家们喜欢用，其他好像都不对。
2、一个细节题问beetle为什么比pollen更靠谱
原文中有contaminated by long-distant wind-啥的 pollen，应该是选花粉被污染那个选项
［B可以在短时间内怎样怎样］
［rapidly respond---quickly adapt］
［我选的甲虫的反应更quick一类的选项］
3、第三段的作用
我选的evaluate什么
［应该是Scientists 具体如何用beetle来测climate change］

Riff

2.1.11 热带雨林植物多样性
阅读还有一个是讲热带雨林植物的多样性，分析tropical plants为什么会生长得这么好，貌似说的是植物生存过程中的竞争性。有一段，三个理论，第一个是说在食草动物识破了plants的各种诡计后大量地吃它们，plants为了存活，遵循适者生存，开发出其他可以避免被吃掉的特征［植物为防动物吃也在进化］（这里考了一个逻辑题，类比关系，我选的butterfly跟花的那个选项）。第二个理论是关于冰河ice age合并的，冰河那个理解先是冰河分割了雨林，形成不同的带，接着才合并。第三个理论说是地震地址运动，火山等导致。最后作者指出对于第一和第二种理论，都有相应的证据或原因给出反对，而第三种理论由于暂时没有反对的证据出现，而被植物学家所接受。
题目：
1、关于问"refuge"（庇护）理论的infer题：
应该选“不同的refuge有不同的plant”那个选项。（有个易混的选项是“refuge的merge导致了雨林里的植物开始diversify”，看似很像其实不对。因为文章的原文是：小块refuge先生长植物，然后再merge形成雨林，这样雨林里的植物就更diversify了，其意就是refugee的植物是不同的。）
［正确的选项开头有个varision就是“不同”个词。好像是B］
［我选的是不同的refuge plant是不同的］
2、主旨题：
是介绍不同的理论about ecosystem phenomena, 不是理论in dealing with ecosystem situation
3、逻辑题：下面哪个能够削弱第二个理论
4、问的第一种theory说产生plant diversity的原因。（Natural Selection）
因为animal eaters were evolved to counter the self-protecting mechanism of plant, 所以plant也得进化。