VOA慢速英语2019 地球最早可移动生物追溯至21亿年前

Earth’s Earliest Mobile Organism Lived 2.1 Billion Years Ago

Scientists have discovered the oldest fossil evidence of organism motility, or the ability of an organism to move independently. The discovery shows that development of motility began more than two billion years ago.

科学家们发现了最古老的化石证据，证明了生物体的运动性，即生物体独立运动的能力。这一发现表明，运动能力的发展始于20多亿年前。

The fossils were found in Gabon, in rock called shale¹. Researchers described them as tube-like structures up to 170 millimeters long. They say the structures may have been created when the organisms moved through soft, wet dirt in search of food or a better environment.

这些化石是在加蓬的页岩中发现的。研究人员称其为“长达170毫米的管状结构”。他们说，这些结构可能是某种生物在柔软潮湿的泥土中觅食或更舒适的生存环境时行成的。

The researchers also said the organisms might have been moving together as a group. The organisms remains² a mystery as the fossils are a record only of their movement.

研究人员还说，这些生物可能是作为群体一起移动的。这些生物的本体仍然成谜，因为这些化石只是它们运动的记录。

The researchers said the fossils dated back to a time when Earth was rich with oxygen. These conditions permitted simple life forms to develop more complexity³.

研究人员说，这些化石可追溯到地球上氧气丰富的时代。简单细胞生命体才得以进化为复杂结构生命体。

Life on Earth started with single-celled bacteria about 4 billion years ago. The earliest life forms could not move under their own power. The Gabon fossils dated to the Paleoproterozoic Era are about 1.5 billion years older than the previous earliest evidence of organism motility.

地球上的生命始于约40亿年前的单细胞细菌。最早的生命体无法依靠自己的力量移动。加蓬的化石可以追溯到古元古代，比先前最早的生物活动的证据要推前15亿年。

Abderrazak El Albani, a scientist with the University of Poitiers in France, led the team in Gabon. The shale deposit there has proven to be a treasure for the study of ancient life. Several years ago, Albani and his team discovered it held the oldest fossils know of multicellular animals.

法国普瓦捷大学的科学家阿卜杜勒－埃尔·阿尔巴尼（Abderrazak El Albani）在加蓬领导了这一研究小组。当地页岩矿床已被证明是研究古代生命的宝库。几年前，阿尔巴尼和他的研究小组发现这里保存着已知的最古老的多细胞动物化石。

“What matters here is their astonishing complexity and diversity in shape and size, and likely in terms of metabolic⁴, developmental and behavioral patterns, including the just-discovered earliest evidence of motility, at least for certain among them,” Albani said.

“重要的是它们在形状和大小方面惊人的复杂性和多样性，也有可能在代谢、发育和行为模式方面，包括刚发现的最早的运动性证据，至少这些发现是可以肯定的，”阿尔巴尼说道。

The first vertebrates, or animals with backbones⁵, appeared about 525 million years ago. Dinosaurs⁶ came about 230 million years ago and human-like species developed about 300,000 years ago.

最早的脊椎动物出现在约5.25亿年前。恐龙大约出现在2.3亿年前，类人物种大约于30万年前形成。

Scientists believe this early time in motility may have faced a setback⁷ soon after the Paleoproterozoic Era, about the time of the Gabon fossils. The Earth saw a considerable loss of atmospheric⁸ oxygen at that time.

科学家们认为，这种早期的活动性可能在古元古代（大约是加蓬化石年代）后不久就开始发生倒退。当时地球大气中的氧气开始大量流失。

The research was published in the Proceedings⁹ of the National Academy of Sciences.

I'm Pete Musto.

Words in This Story

fossil – n. something, such as a leaf, skeleton, or footprint, that is from a plant or animal which lived in ancient times and that you can see in some rocks

deposit – n. an amount of a substance, such as oil or coal, that exists naturally in the ground

astonishing – adj. causing a feeling of great surprise or wonder

diversity – n. the quality or state of having many different forms, types, ideas, etc.

metabolic – adj. of or relating to the chemical processes by which a plant or an animal uses food, water, etc., to grow and heal and to make energy

1 shale   

n.页岩，泥板岩

参考例句：

• We can extract oil from shale.我们可以从页岩中提取石油。
• Most of the rock in this mountain is shale.这座山上大部分的岩石都是页岩。

2 remains   

n.剩余物，残留物；遗体，遗迹

参考例句：

• He ate the remains of food hungrily.他狼吞虎咽地吃剩余的食物。
• The remains of the meal were fed to the dog.残羹剩饭喂狗了。

3 complexity   

n.复杂(性)，复杂的事物

参考例句：

• Only now did he understand the full complexity of the problem.直到现在他才明白这一问题的全部复杂性。
• The complexity of the road map puzzled me.错综复杂的公路图把我搞糊涂了。

4 metabolic   

adj.新陈代谢的

参考例句：

• Impressive metabolic alternations have been undergone during embryogenesis.在胚胎发生期间经历了深刻的代谢变化。
• A number of intoxicants are associated with metabolic acidosis.许多毒性物质可引起代谢性酸中毒。

5 backbones   

n.骨干( backbone的名词复数 )；脊骨；骨气；脊骨状物

参考例句：

• Why do hummingbirds and gorillas both have backbones? 为什么蜂鸟和大猩猩都有脊骨？ 来自辞典例句
• Simply adding bandwidth to the Internet backbones is not an answer. 只是简单的在互联网骨架上增加带宽是应付不了的。 来自互联网

6 dinosaurs   

n.恐龙( dinosaur的名词复数 )；守旧落伍的人，过时落后的东西

参考例句：

• The brontosaurus was one of the largest of all dinosaurs. 雷龙是所有恐龙中最大的一种。 来自《简明英汉词典》
• Dinosaurs have been extinct for millions of years. 恐龙绝种已有几百万年了。 来自《简明英汉词典》

7 setback   

n.退步，挫折，挫败

参考例句：

• Since that time there has never been any setback in his career.从那时起他在事业上一直没有遇到周折。
• She views every minor setback as a disaster.她把每个较小的挫折都看成重大灾难。

8 atmospheric   

adj.大气的，空气的；大气层的；大气所引起的

参考例句：

• Sea surface temperatures and atmospheric circulation are strongly coupled.海洋表面温度与大气环流是密切相关的。
• Clouds return radiant energy to the surface primarily via the atmospheric window.云主要通过大气窗区向地表辐射能量。

9 proceedings   

n.进程，过程，议程；诉讼(程序)；公报

参考例句：

• He was released on bail pending committal proceedings. 他交保获释正在候审。
• to initiate legal proceedings against sb 对某人提起诉讼