Scientists Find Remains of Extinct Tiny Human
时间:2019-01-03 作者:英语课 分类:VOA2004(下)--健康科技
By David McAlary
Scientists have discovered fossils of an ancient, tiny species of human in an isolated 1 part of Indonesia. They are bones from what they say is a smaller version of the now extinct immediate 2 ancestor to modern humans. Some observers call it a surprising twig 3 on our family tree, one that co-existed with modern humans until relatively 4 recently, long after their normal-sized archaic 5 counterparts disappeared.
The remote eastern Indonesian Island of Flores is an exotic place, with large lizards 6 known as Komodo dragons and remains 7 of extinct dwarf 8 elephants and miniature humans.
It is the discovery of the chimpanzee-sized humans that is causing excitement among scientists. Australian researchers report in the journal Nature that they found the bones of an adult female who stood just one meter tall with a head the size of a grapefruit. Since submitting the paper for publication, they found the remains of five or six more of these wee (small) people, who lived as recently as 12,000 years ago, just before the dawn of civilization.
"In evolutionary 9 terms, 12,000 years is just yesterday," this is University of New England researcher, Peter Brown who admits to being flabbergasted when he realized these tiny archaic people had a brain one-fourth the size of modern humans.
"My colleagues reported that when I measured the size of the brain, I went pale and my jaw 10 dropped to my knees because people with this brain size were supposed to have become extinct more than three million years ago, but here we had a small-bodied human relative with a very small brain surviving until the relatively recent past, like we have only just missed them," he said.
Mr. Brown says the bones are not those of the three million-year-old pre-humans to which he referred. Rather, they belong to a small newer human thought to be our modern species most immediate ancestor, Homo erectus. But the size of the creature has earned it the right to be its own species. Mr. Brown's team calls it "Flores Man."
But Homo erectus was much larger, so how did Flores Man become small? The Australian team believes the full-sized erectus people arrived on Flores 840,000 years ago, perhaps from Java, after a million-year migration 11 out of Africa. This view is based on the dating of stone tools found on Flores in an earlier excavation 12.
Mr. Brown believes that over time, the species shrank on the isolated island.
"It underwent similar selection processes which happen to many other mammals on islands," said Peter Brown. "And in the absence of large predators 13 and with reduced calories and a heavy covering of rain forest, it became much smaller in body size."
Evidence gathered with Flores Man suggests the tiny species made its own tools and hunted, like Homo erectus. Remains of a dwarf elephant called Stegodon were near the human bones.
But unlike Homo erectus, which died out by at least 40,000 years ago and maybe earlier, Flores Man stayed around a lot longer. The Australians believe a volcano eruption 14 finally killed them off 12,000 years ago, as modern humans were populating the Americas. This belief is based on the dating of ash layers with the bones.
Scientific reaction to the discovery has been enthusiastic. "Breathtaking" is the word used by University of Cambridge anthropologist 15 Robert Foley. At the Natural History Museum in London, Christopher Stringer calls it remarkable 16, not only for the size and duration of Flores Man, but also because early humans managed to get to the remote island.
"This island is a lot further away than Java," said Christopher Stringer. "Humans could have gotten to the island of Java. At times of low sea level, Java was connected to the rest of southeast Asia. But the islands beyond Java, including Flores, are separated by deep water, so it was not thought that ancient humans could have got across that deep water."
That implies that Homo erectus had mastered the technology of boats. As for their diminutive 17 descendants, Mr. Stringer says they are another example of the variety of humans that once existed.
"It shows us that human evolution, even in the recent past, was complex," he said. "There were many different species and nature was conducting its own evolutionary experiments with early humans."
The Australian researchers suggest other remote Indonesian islands could be hiding similar surprises and plan to dig on them to find out.
David McAlary ,VOA News, Washington.
注释:
fossil 化石
version 形式
ancestor 祖先
archaic 古代的
Komodo dragon 科摩多龙
dwarf 矮小
chimpanzee 黑猩猩
flabbergaste 使大吃一惊
Java 爪哇(印度尼西亚的一个岛屿)
excavation 出土文物
Stegodon 剑齿象
enthusiastic 热心的
- His bad behaviour was just an isolated incident. 他的不良行为只是个别事件。
- Patients with the disease should be isolated. 这种病的患者应予以隔离。
- His immediate neighbours felt it their duty to call.他的近邻认为他们有责任去拜访。
- We declared ourselves for the immediate convocation of the meeting.我们主张立即召开这个会议。
- He heard the sharp crack of a twig.他听到树枝清脆的断裂声。
- The sharp sound of a twig snapping scared the badger away.细枝突然折断的刺耳声把獾惊跑了。
- The rabbit is a relatively recent introduction in Australia.兔子是相对较新引入澳大利亚的物种。
- The operation was relatively painless.手术相对来说不痛。
- The company does some things in archaic ways,such as not using computers for bookkeeping.这个公司有些做法陈旧,如记账不使用电脑。
- Shaanxi is one of the Chinese archaic civilized origins which has a long history.陕西省是中国古代文明发祥之一,有悠久的历史。
- Nothing lives in Pompeii except crickets and beetles and lizards. 在庞培城里除了蟋蟀、甲壳虫和蜥蜴外,没有别的生物。 来自辞典例句
- Can lizards reproduce their tails? 蜥蜴的尾巴断了以后能再生吗? 来自辞典例句
- 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。
- The dwarf's long arms were not proportional to his height.那侏儒的长臂与他的身高不成比例。
- The dwarf shrugged his shoulders and shook his head. 矮子耸耸肩膀,摇摇头。
- Life has its own evolutionary process.生命有其自身的进化过程。
- These are fascinating questions to be resolved by the evolutionary studies of plants.这些十分吸引人的问题将在研究植物进化过程中得以解决。
- He delivered a right hook to his opponent's jaw.他给了对方下巴一记右钩拳。
- A strong square jaw is a sign of firm character.强健的方下巴是刚毅性格的标志。
- Swallows begin their migration south in autumn.燕子在秋季开始向南方迁移。
- He described the vernal migration of birds in detail.他详细地描述了鸟的春季移居。
- The bad weather has hung up the work of excavation.天气不好耽误了挖掘工作。
- The excavation exposed some ancient ruins.这次挖掘暴露出一些古遗迹。
- birds and their earthbound predators 鸟和地面上捕食它们的动物
- The eyes of predators are highly sensitive to the slightest movement. 捕食性动物的眼睛能感觉到最细小的动静。 来自《简明英汉词典》
- The temple was destroyed in the violent eruption of 1470 BC.庙宇在公元前1470年猛烈的火山爆发中摧毁了。
- The eruption of a volcano is spontaneous.火山的爆发是自发的。
- The lecturer is an anthropologist.这位讲师是人类学家。
- The anthropologist unearthed the skull of an ancient human at the site.人类学家在这个遗址挖掘出那块古人类的颅骨。
- She has made remarkable headway in her writing skills.她在写作技巧方面有了长足进步。
- These cars are remarkable for the quietness of their engines.这些汽车因发动机没有噪音而不同凡响。
- Despite its diminutive size,the car is quite comfortable.尽管这辆车很小,但相当舒服。
- She has diminutive hands for an adult.作为一个成年人,她的手显得非常小。