考满分 toefl

1 .Listen to part of a lecture in a paleontology class.

听一段古生物学课程中的演讲

1 .As we've discussed, birds are apparently descendants of dinosaurs and shared many commonalities with some dinosaur species, like... um... feathers and maybe even flight and of course egg laid.

正如我们已经讨论的,鸟类显然是恐龙的后代,与某些恐龙物种有许多共性,像。。。嗯。。。羽毛，甚至飞行,当然还有下蛋了。

1 .OK. So, many paleontologists, myself included, have wondered about other similarities between dinosaurs and birds.

。好吧。因此,许多古生物学家,包括我自己,都想知道恐龙和鸟类之间的其他相似之处。

2 .Since adult dinosaur fossils have sometimes been discovered near or on top of nests, we've been looking at the dinosaur parenting behavior.

自从成年恐龙化石有时被发现在巢的附近或者上面,我们一直关注恐龙育儿行为。

1 .Parenting behavior, well, that sounds so gentle and caring.

育儿行为，哦，听起来那么温柔和充满关怀。

2 .But dinosaurs were ferocious reptiles and reptiles don't take care of their young, do they?

但恐龙是凶猛的爬行动物，爬行动物不照顾他们的后代,不是吗?

1 .Well, some reptiles incubate their eggs, crocodiles do.

嗯,一些爬行动物会孵化他们的蛋,像是鳄鱼。

2 .And as for popular attitudes towards dinosaurs... well, take the Oviraptor for instance.

至于现在对于恐龙的普遍观点。。。嗯，举个偷蛋龙的例子。

1 .In the 1920s, a paleontologist discovered the fossil remains of a small dinosaur near a nest containing eggs.

。在二十世纪二十年代，一个古生物学家发现了一个小恐龙在一个有着恐龙蛋的巢旁边的化石

2 .He assumed the dinosaur was stealing the eggs, so he named it Oviraptor that means egg thief in Latin, which fueled the generally negative public image of such dinosaurs.

他猜测这个恐龙正在偷蛋，所以他把这种恐龙命名Oviraptor，在拉丁语中是偷蛋贼的意思，这激起了公众对这样的恐龙产生了普遍的负面形象。

1 .But by the 1990s, other experts had convincingly made the case that instead of robbing the nest, the Oviraptor was probably taking care of the eggs.

但是到了二十世纪九十年代，另一些专家证实这种情况并非洗劫恐龙巢，偷蛋龙可能正在照顾恐龙蛋

2 .You see, dinosaurs' closest living relatives - birds and crocodiles - display nesting behavior.

你看，恐龙存活着的近亲－鸟类和鳄鱼－都有育儿行为。

3 .And dinosaur fossils have been found in postures that we now believe to indicate brooding behavior, that is, sitting on the eggs until they hatch.

因此我们相信已经找到的恐龙化石的姿势就是孵化行为，那就是，坐在蛋上直到孵化。

1 .So we are curious about the type of care dinosaurs gave to their young.

所以我们对于恐龙照顾他们后代的方式很好奇。

2 .And we'd like to figure out which dinosaur parent, the male or the female gave the care.

而且我们希望弄清楚是母亲还是父亲照顾他们的后代。

1 .Shouldn't the behavior of crocodiles and birds give us some clues then?

那么我们不能从鸟类和鳄鱼的行为上得到一些暗示吗？

1 .Well, with crocodiles, it is the female who guards the nest, and with birds, it depends on the species, it can be the male or the female that takes care the eggs, or both.

嗯，鳄鱼是母亲照顾他们的巢，鸟类则取决于他们的种类，他们可能是母亲或父亲或者双方都照顾巢

2 .In over 90 percent of all bird species, both parents take care of the eggs and the young birds.

在所有鸟的种类中，超过百分之九十的都是父母照顾鸟蛋和幼鸟。

1 .But sometimes it's just the male?

但是有时候只是雄鸟照顾？

1 .Well, exclusive care by the male parent is much less common, but it does occur.

由雄鸟单独照顾的情况很不常见，但是偶尔也会这样。

2 .Now, for animals other than birds, the care of young by both parents is pretty unusual in the animal kingdom.

在动物王国中，就除了鸟类以外的动物来说，父母双方照顾幼崽是很不常见的

3 .Males contribute to parental care in fewer than five percent of all mammalian species.

在哺乳动物中，雄性照顾后代的占不到百分之五。

4 .It's even less frequent among reptiles, and exclusive care by the male is very rare.

在爬行动物中比例更小.由雄性专职照顾后代的很罕见。

5 .So researchers have wondered about the evolution of male parenting behavior in birds for quite some time.

所以研究人员认为在鸟类中，由雄鸟照顾后代这一行为的进化已经有一段时间了

6 .And now there's research showing that for some of the birds' dinosaur relatives, it's likely that the male parent was also in charge of taking care of the eggs.

。现在的调查显示一些鸟类恐龙的亲戚，很可能雄性一方也是负责照顾恐龙蛋的。

1 .How did they figure that out?

那研究人员是怎么知道的呢？

1 .Well, first they looked at clutch volume, that's the number of eggs in the nest of crocodiles, birds and three types of dinosaurs, including Oviraptors that are thought to be closely related to the dinosaur ancestors of birds.

嗯首先他们观察了巢的体积，鳄鱼，鸟和三种恐龙的巢里蛋的数量，包括被认为是和鸟类的恐龙祖先是近亲的偷蛋龙。

2 .So when researchers examined fossilized remains of nests, they found that the dinosaurs had larger clutch volumes, more eggs in the nests that is, than most of the crocodiles and birds that were studied.

所以当研究人员研究恐龙巢化石时，他们发现相比于所研究的鳄鱼和鸟的最大的巢和最多的蛋，恐龙巢的体积更大，蛋更多。

3 .But, and this is important, their clutch volumes matched those of birds that have only male parental care.

但是，重要的是，他们的巢都是雄性恐龙在照顾。

4 .You see, bird species in which only the males take care of the nest tend to have the largest clutches of eggs.

你看，鸟类中，由雄鸟照顾的巢有最大的体积和最多的蛋。

1 .So what's the connection between bird and dinosaur behavior?

所以，鸟类和恐龙的行为之间有什么联系呢？

1 .Well, researchers now believe, because of this study, that the male parenting behavior of these birds might have its origins in the behavior of dinosaurs.

由于以上的研究，现在，研究人员认为一些鸟类由雄性抚育后代的行为也许起源于这些恐龙。

1 .Based only on evidence of clutch volume size, the number of eggs?

仅仅基于巢的体积和蛋的数量？

1 .No, there's more.

不，有更多证据。

2 .They also examined the fossilized bones of those three types of dinosaurs that were found on or near nests to determine their sex.

他们还研究了在巢上方和附近的三种恐龙的骨头化石来确定这些恐龙的性别。

3 .You see, adult female birds during egg production produce a layer of spongy bone tissue inside certain long bones.

你看，成年雌鸟在产蛋时在某些长骨头会产生一层海绵骨组织。

4 .And so did female dinosaurs of the kinds that were investigated.

所以，在雌性恐龙的种类调查时发现确实是这样。

5 .This spongy tissue serves as a source of calcium for eggshell formation.

这个海绵组织是蛋壳形成的钙源。

6 .But when the dinosaur fossils were examined, there were no spongy bone deposits.

但是,当恐龙化石进行检测时,发现没有海绵骨组织。

1 .Meaning that those dinosaurs on the nests were probably adult males who wouldn't have needed calcium for making eggshells.

这就意味着那些在巢上方的可能是不需要钙来形成蛋壳的雄性恐龙。

1 .Exactly. And then there's this: birds like the kiwi, the ostrich and the emu, they share certain physical characteristics with these dinosaurs, and interestingly, they also show a consistent pattern of nest care by the male.

正确。还有:鸟类像几维（一种新西兰产的无翼鸟），鸵鸟和鸸鹋；他们与这些恐龙有着某些相同的物理特性。有趣的是,他们也表现出一致的雄性照顾巢的模式。