Ancient bones unearthed in China are helping scientists better understand the development, or evolution, of modern pandas.在中國出土的古代大熊貓骨骼正在幫助科學家更好地了解現代大熊貓的發展或進化過程。 Pandas are a kind of animal called bears that live in forests in the mountains of Southwestern China.大熊貓是熊的一種，生活在中國西南部山區的森林裡。 Pandas' main food is a plant called bamboo.大熊貓的主要食物是一種叫做竹子的植物。 Currently, experts estimate the wild population of pandas is under 2,000.目前，專家估計野生大熊貓數量不足2000隻。 Researchers recently reported that they discovered fossils, or mineralized bones, from an extinct panda called Ailurarctos.研究人員最近報告稱，他們發現了一種叫做「始熊貓」的滅絕大熊貓的化石或礦化骨骼。 The fossils were found near the city of Zhaotong in the northern Yunnan Province in China.這些化石是在中國雲南省北部的昭通市附近發現的。 They are about 6 million years old and are from an ancestor to the modern panda.它們大約有600萬年的歷史，來自於現代大熊貓的祖先。 The fossils helped scientists understand the evolution of a bone structure that helps pandas eat bamboo called a false thumb.這些化石幫助科學家了解了輔助大熊貓吃竹子的一種骨骼結構的進化，這種骨骼結構叫做偽拇指。 The false thumb found on Ailurarctos is similar to those found on modern pandas.在「始熊貓」身上發現的偽拇指與在現代大熊貓身上發現的相似。 But, it is longer and lacks a hook that living pandas use to eat bamboo.但是，在「始熊貓」身上發現的偽拇指更長，而且沒有現存大熊貓用來吃竹子的那個鈎。 The fossils are the oldest-known evidence of the false thumb, which is really an enlarged wrist bone called the radial sesamoid.這些化石是目前已知關於偽拇指的最古老證據，偽拇指實際上是一塊叫做橈側籽骨的增大腕骨。 The wrist is a joint of the body that permits the hand to move.手腕是身體的一個關節，它使手可以活動。 The false thumb is an adaptation that helps the existing five fingers, or digits, hold objects.偽拇指是為了幫助已有的五根手指握住物體而產生的適應性變化。 A bear's hand lacks an opposable thumb, a true digit.熊的手沒有對生拇指，真正的手指。 Humans and other related animals, called primates, possess opposable thumbs.人類和其他被稱為靈長類動物的親緣物種擁有對生拇指。 They permit primates to hold and handle objects using fingers.對生拇指允許靈長類動物用手指握住和掌控物體。 The false thumb operates in a similar way.偽拇指的作用和對生拇指類似。 The researchers first found an Ailurarctos arm bone in 2010.研究人員在2010年首次發現了「始熊貓」的臂骨。 They then discovered teeth and the false thumb in 2015, giving them a better understanding of the animal.然後他們在2015年發現了「始熊貓」牙齒和偽拇指，那讓他們更好地了解了這種動物。 Until now, the oldest-known evidence of this thumb-like structure was 102,000 to 49,000 years old.到目前為止，關於這種類拇指結構的已知最古老證據可以追溯到10.2萬到4.9萬年前。 It came from the same kind of panda that is alive today.該證據來源於和現存大熊貓同種的大熊貓。 The false thumb was not present in another closely related bear that lived about 9 million years ago, the researchers said.研究人員說，生活在900萬年前的另一大熊貓近親沒有偽拇指。 Xiaoming Wang is the lead writer of the research published in the Scientific Reports.王曉明是發表在《科學報告》上的該研究的主要作者。 He studies fossils at the Natural History Museum of Los Angeles County.他在洛杉磯縣自然歷史博物館研究化石。 Wang said: "It uses the false thumb as a very crude opposable thumb to grasp bamboo,王說：「它利用偽拇指作為一種非常粗糙的對生拇指來抓住竹子， sort of like our own thumbs except it is located at the wrist and is much shorter than human thumbs."有點像我們自己的拇指，只不過偽拇指位於手腕處，比人類的拇指短得多。」 The modern panda's false thumb is more useful than the earlier version found in Ailurarctos.現代大熊貓的偽拇指比在「始熊貓」身上發現的早期偽拇指更有用。 Wang said the hooked false thumb offers a better grasp and it comes out less from the body.王說，鈎狀偽拇指能更好地抓握，從身體中凸出的部分也更少。 That makes it easier for the panda to walk.這使得大熊貓走路更容易。 Wang said scientists think that is the reason the false thumb in modern pandas has become shorter, not longer.王說科學家認為，這就是現代大熊貓的偽拇指變得更短而非更長的原因。 The false thumb lets pandas hold bamboo to eat but not to turn the food as a thumb would permit.偽拇指可以讓大熊貓拿着竹子吃，但不像拇指一樣能轉動食物。 Tao Deng of the Chinese Academy of Sciences in Beijing is a paleontologist and co-writer of the study.北京中國科學院的鄧濤是一位古生物學家，也是這項研究的合著者。 He said, "The panda's false thumb is far less effective than the human thumb,他說：「大熊貓的偽拇指遠不如人類的拇指有用， but is enough to provide the giant panda with the grasping ability to eat bamboo."但它足以讓大熊貓獲得抓握能力來吃竹子。」 I'm Gregory Stachel.格里高利·施塔赫爾為您播報。
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