- August 14, 2005 at 1:30 pm #128228
人 類 和 現 代 大 型 猿 類 動 物 在 進 化 史 上 最 後 一 個 共 同 祖 先
( 星 島 日 報 報 道 ) 人 類 和 現 代 大 型 猿 類 動 物 在 進 化 史 上 最 後 一 個 共 同 祖 先 ， 可 能 就 是 西 班 牙 東 北 部 最 近 出 土 的 化 石 主 人 ─ ─ 爬 樹 類 動 物 。
西 班 牙 米 格 爾 ． 克 魯 薩 方 特 古 生 物 學 研 究 院 專 家 索 拉 所 率 領 的 探 挖 小 組 ， 在 巴 塞 隆 那 郊 外 二 十 里 的 一 個 「 小 盆 地 」 ， 發 現 了 八 十 三 件 來 自 同 一 種 動 物 的 骸 骨 化 石 ， 年 代 可 以 追 溯 到 一 千 三 百 萬 年 前 。
這 批 化 石 分 別 屬 於 頭 蓋 骨 、 椎 骨 、 腕 骨 和 身 體 其 他 部 位 的 骨 頭 。 經 過 拼 湊 後 ， 科 學 家 發 現 ， 化 石 主 人 屬 於 雄 性 ， 有
- August 14, 2005 at 1:32 pm #79726
Fossil find may be the father of us all
It\’s hailed as last common kin of the great apes and humans
David Perlman, Chronicle Science Editor
Monday, November 22, 2004
Spanish anthropologists, intrigued by a single fossil tooth found near a Catalonian village, dug up more of the animal\’s stony skeleton and announced they have discovered what may be the last common ancestor of all the world\’s living great apes — including the human family.
And unlike theories on the evolution of human running that provoked strong controversy last week, the find is being heralded as highly significant and filled with fresh insights into the long and murky quest for understanding how Homo sapiens came to be.
The Spanish scientists are calling their new ape species Pierolapithecus catalaunicus and say that it must have lived nearly 13 million years ago, during a period known geologically as the Middle Miocene — a time for which the fossil evidence of animal life has been extremely scarce until now.
The ancient ape or its close relatives, the scientists believe, would have been the ancestor of today\’s chimpanzees, gorillas, orangutans and, of course, humans. The entire great ape lineage was separated millions of years earlier from the lesser apes like gibbons and siamangs, as well as by the monkeys of both the New World and the Old, they say.
The leader of the anthropology team is Salvador Moya-Sola of Barcelona\’s Paleontology Institute, and his group\’s report was published Friday in the journal Science.
During a telephone press conference from Spain, Meike Kohler, one of the scientists, said she pictures their ancient ape\’s features as \”a kind of bridge between something more primitive and something more advanced — not a missing link, but a basic body design leading to modern apes and humans.\”
\”This is really an exciting discovery,\” C. Owen Lovejoy of Kent State University in Ohio, a veteran expert on primate fossils and human evolution who is familiar with the work but not connected to the group, said in an interview. \”It is filling in what until now has seen only the most meager evidence for the idea, but now the fossil evidence seems strong.\”
The extraordinary find comes from a new and rich fossil site, near the village of Hostalets de Pierola, and it \”promises to contribute substantially to our understanding of the origin of extant great apes and humans,\” Moya-Sola said.
The name Pierolapithecus for the fossil bones of the primitive ape combines part of the village\’s name with the Greek word for ape, while catalaunicus derives from Catalonia, the province where both the village and Barcelona are located.
The trove of bones the scientists uncovered there included all or parts of the skull, the metacarpal bones of both hands and feet, pieces of toes and fingers, three vertebrae, two complete ribs and large fragments of a dozen others.
From those 83 fossils, Moya-Sola and his colleagues deduced they had found the bones of what was most probably a single adult male that weighed about 75 pounds, and was well adapted for tree climbing while upright and for knuckle-walking on the ground. And from the shape of the single surviving tooth, it was probably a fruit-eater, the scientists deduced.
Several significant features distinguish the primitive ape from the lesser apes and monkeys, the anthropologists say. For example, its rib cage, lower spine and wrist indicate it climbed the way modern great apes do; although the even more primitive monkeys also climb, their bones are very different.
The ape\’s chest, or thorax, is wider and flatter than that of monkeys, Moya-Sola said, adding: \”The thorax is the most important anatomical part of this fossil, because it is the first time that the modern ape-like thorax has been found in the fossil record.\”
In the current timetable of early primate evolution inferred by most anthropologists, the lineage of tail-bearing monkeys split off about 25 million years ago from the line that developed toward apes and humans. The gibbons and siamang lines split from the apes 14 to 16 million years ago. The great apes, with their strong upright posture, continued evolving. The orangutans split off from that line about 10 or 11 million years ago, and were followed by another split when the gorilla line branched off, leaving the ancestors of the chimpanzees.
Then about 6 to 7 million years ago came another split in the lineage, which led to the many separate branches of hominids — the Ardipithecines, the Australopithecines and eventually the genus Homo: Homo habilis, Homo erectus, and now, Homo sapiens, or us.
To Lovejoy, the Spanish scientists have struck real gold.
\”Up to now all we\’ve had is bits and scraps of evidence,\” he said. \”But this skeleton is relatively complete, and its wrist bones show one of the premier adaptations of modern great apes — a formation we call ulnar deviation. Monkeys don\’t have it, but great apes and humans do.
\”It\’s the wrist structure that a baseball pitcher can use when he throws — first twisting his right hand back and toward his right — if he\’s right- handed — and then swinging the hand forward and bending it 90 almost degrees toward his left. Monkeys can\’t do that at all.\”
Another significant difference from monkeys that makes the Spanish fossil find so significant, Lovejoy said, is the shape of the ape\’s lower back and thorax — \”it\’s a shape that lets him move through the trees by a new form of locomotion that monkeys never achieved,\” he said.
The great ape lineage, Lovejoy said, \”went through a whole host of adaptive changes over millions of years. In my view — and the Spanish fossils mark a start — the apes grew bigger and bigger, and a lot smarter.\”
- August 14, 2005 at 1:59 pm #118658
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