人類演化 Human Evolution

圖根原人是第二古老與人類有關的人族 (Hominin) 祖先，是原人屬（或稱千年人屬）中的唯一種。

發現的化石最少是來自5個個體。化石包括了大腿骨、右肱骨及牙齒。從大腿骨得知他們是直立行走的，肱骨部份可見是能攀樹（但非臂行），而牙齒則顯示他們的食性與現今人類相似。另外在大腿骨後部有閉孔外肌溝，可見他們是雙足行走的。從丘狀齒、有微齒的臼齒及細小的犬齒可見他們主要是吃生果及蔬菜，有時會吃肉。千年人屬約有現今黑猩猩的大小。

Considered to be the second-oldest known hominin ancestor that is possibly related to modern humans and is the only species classified in genus Orrorin. The name was given by the discoverers who found Orrorin fossils in the Tugen Hills of Kenya. By using radiometric dating techniques, the volcanic tuffs and lavas, faunal correlation and magneto-stratigraphy, the strata in which the fossils were found were estimated to date between 6.1 and 5.8 million years ago, during the Miocene. This find is important because it is possibly an early bipedal hominin.

The fossils found so far come from at least five individuals. They include a proximal femur, which is insufficient evidence to prove that it was bipedal, though some scholars suggest that Orrorin walked upright; a right humerus shaft, suggestive of tree-climbing skills but not brachiation; and teeth that suggest a diet similar to Paranthropoids. The obturator externus groove on the posterior aspect of the neck of the fossil femur suggests that Orrorin tugenensis moved bipedally. The bunodont, microdont molars and small canines suggest that Orrorin ate mostly fruit and vegetables, with occasional meat. Orrorin was about the size of a modern chimpanzee.

Name 學名﹕Ardipithecus ramidus 地猿

Other names 別名﹕Ardi﹐拉瑪猿

Discovered 出土年份﹕1994

Place 地點﹕ Ethiopia 埃塞俄比亞

Age 年份﹕ 4.4 - 3.3 mya

枕骨大孔及腳骨的特徵顯示牠是雙足行走的。估計牠們的體型接近現今的黑猩猩。

從始祖地猿的趾骨結構，可見牠是可以站立行走。這卻引起了人科雙足行走起源的問題。因為一般相信雙足行走在大草原是最為節能的，但地猿卻是生活在森林中而非大草原。

It was originally dated at 4.4 million years, but has since been discovered to far back as 5.8 million years. Most remains are skull fragments. Indirect evidence suggests that it was possibly bipedal, and that some individuals were about 122 cm (4'0") tall. The teeth are intermediate between those of earlier apes and A. afarensis, but one baby tooth is very primitive, resembling a chimpanzee tooth more than any other known hominid tooth. Other fossils found with ramidus indicate that it may have been a forest dweller. This may cause revision of current theories about why hominids became bipedal, which often link bipedalism with a move to a savannah environment. (White and his colleagues have since discovered a ramidus skeleton which is about 45% complete, but have not yet published on it.)

2009一個更加完整的遺骸化石被發現 2009 a more complete set of fossils were found

http://news.nationalgeographic.com/news/2009/10/091001-oldest-human-skeleton-ardi-missing-link-chimps-ardipithecus-ramidus.html

Name 學名﹕Australopithecus afarensis 阿法南方古猿

Other names 別名﹕Lucy

Discovered 出土年份﹕1994

Place 地點﹕ Ethiopia 埃塞俄比亞

Age 年份﹕ 3.9 - 3.0 mya

與現今及已滅絕的類人猿比較，阿法南方古猿的犬齒及臼齒較細小，但體型卻比現今人類較大。阿法南方古猿的腦部亦較小，只有約380-430立方厘米，有下巴突出的面部。

阿法南方古猿細小的腦部及原始面孔，加上雙足行走的發現，改革了當時古人類學的想法。因為最初認為人類的最先及重大的轉變是增大腦部。

阿法南方古猿﹐又名阿法南猿或南方古猿阿法種，是生存於390-290萬年前已滅絕的人科。牠與較年輕的非洲南方古猿一樣都是較修長的。研究發現阿法南方古猿是南方古猿屬及人屬的祖先。對於阿法南方古猿的行走模式有著很多爭論。一些學者相信牠差不多是完全雙足行走的，而其他的則認為牠是部份棲於樹上的。手、腳及肩膀關節的結構都支持後者的說法。手指的彎曲及趾骨像現今的猿，足以表示牠們可能用來抓住樹枝攀樹。牠們的手腕可以緊扣，適合指背行走。肩膀關節比現今人類更近頭骨。連同相對較長的手臂，相信阿法南方古猿是伸高雙臂來攀樹的。再者，從頭顱骨的掃瞄中發現溝漕及骨質的迷宮形態，可能牠們並非雙足行走的。

但是阿法南方古猿仍有一些特徵顯示有可能是雙足行走的。整體上說，牠的骨盆較像人的而多於像猿的。牠的胯骨片短而闊，闊的薦骨直接在臀部關節之下，且有明顯證據是連接股直肌。縱然骨盆並非完全像人的，這些特徵都支持是一個某程度雙足行走的結構。牠的大腿骨亦指向膝蓋，令腳更為貼近身體的中線，適合雙足行走。現今的人類、猩猩及蜘蛛猴都有相同的特徵。牠的腳上亦有內收的腳趾，難以用後肢來抓住東西（如樹枝或母體），增加了嬰兒從母體掉下的危險。阿法南方古猿的腳踝關節亦像人類的。

Afarensis had an apelike face with a low forehead, a bony ridge over the eyes, a flat nose, and no chin. They had protruding jaws with large back teeth. Cranial capacity varied from about 375 to 550 cc. The skull is similar to that of a chimpanzee, except for the more humanlike teeth. The canine teeth are much smaller than those of modern apes, but larger and more pointed than those of humans, and shape of the jaw is between the rectangular shape of apes and the parabolic shape of humans. However their pelvis and leg bones far more closely resemble those of modern man, and leave no doubt that they were bipedal (although adapted to walking rather than running (Leakey 1994)). Their bones show that they were physically very strong.

Name 學名﹕Australopithecus africanus 非洲南方古猿

Discovered 出土年份﹕1924

Place 地點﹕ South Africa 南非

Age 年份﹕ 2 - 3 mya

非洲南方古猿（Australopithecus africanus），又名非洲南猿或南方古猿非洲种，是属于早期人科的南方人猿亚科，生存于200-300万年前的上新世。[1]较古老的阿法南方古猿与非洲南方古猿都较纤细，估计是现今人类的直接祖先。化石遗骸显示非洲南方古猿更像现今人类，相似的头颅骨可以容纳更大的脑部及有更像人的五官。

雷蒙·达特（Raymond Dart）于1924年在南非近金伯利的汤恩发现了一些骨头及头颅骨碎片，是为“汤恩幼儿”。该头颅骨有点像猿的，但却有人类的特征，如眼窝、牙齿及枕骨大孔，显示它有人类的姿势。达特将这个标本命名为非洲南方古猿，并指它是猿与人类的中间物种。

Australopithecus africanus was an early hominid, an australopithecine, who lived between 2-3 million years ago in the Pliocene. In common with the older Australopithecus afarensis, A. africanus was slenderly built, or gracile, and was thought to have been a direct ancestor of modern humans. Fossil remains indicate that A. africanus was significantly more like modern humans than A. afarensis, with a more human-like cranium permitting a larger brain and more humanoid facial features.

This species had two famous fossils, the "Taung Child" and "Mrs. Ples".

Raymond Dart was at Taung near Kimberley, South Africa in 1924 when one of his colleagues spotted a few bone fragments and the cranium on the desk of a lime worker.The skull seemed like an odd ape creature sharing human traits such as eye orbits, teeth, and, most importantly, the hole at the base of the skull over the spinal column (the foramen magnum) indicating a human-like posture. Dart assigned the specimen the name Australopithecus africanus ("southern ape of Africa"). This was the first time the word Australopithecus was assigned to any hominid.

Name 學名﹕ Homo Habilis 巧人 / 能人

Discovered 出土年份﹕1960年後

Place 地點﹕ Tanzania 坦桑尼亞

Age 年份﹕ 1.4 - 2.8 mya

Literally means the "Handy man", a species of genus homo, which lived from approximately 2.3 million to 1.4 million years ago.It is the earliest known species of the genus Homo. In its appearance and morphology H. habilis is thus the least similar to modern humans of all species in the genus (except possibly H. rudolfensis). H. habilis was short and had disproportionately long arms compared to modern humans; however, it had a less protruding face than the australopithecines from which it is thought to have descended.

Despite the ape-like morphology of the bodies, H. habilis remains are often accompanied by primitive stone tools.

Homo habilis has often been thought to be the ancestor of the lankier and more sophisticated Homo ergaster, which in turn gave rise to the more human-appearing species, Homo erectus. Debates continue over whether H. habilis is a direct human ancestor, and whether all of the known fossils are properly attributed to the species. However, in 2007, new findings suggest that the two species coexisted and may be separate lineages from a common ancestor instead of H. erectus being descended from H. habilis.

是靈長目動物裡第一種被認為屬於人類的生物，是人科人屬中的一個種。生存在約二百五十萬至二百萬年前的東非，是最早出現的人屬動物。

巧人的形態和外觀與現代人類都有很大差別：他們很矮，高度不過130厘米（4'3"），但手臂則相對地很長。一般相信他們是南方古猿的後代，但也許他們更直接的袓先是體型更大、與猿類更相似的盧多爾夫人（Homo rudolfensis）。

一般認為巧人是匠人的袓先，而匠人則是更後期的直立人的袓先。不過有關智人是否巧人的直接後代還有爭議。

Name 學名﹕ Homo Erectus 直立猿人

Discovered 出土年份﹕1960年後

Place 地點﹕ China, Indonesia, Africa 中國﹐印尼﹐非洲﹐歐洲

Age 年份﹕ 2 - 1.5 mya

Homo erectus (from the Latin ērı̆gĕre, "to put up, set upright") is an extinct species of hominid that originated in Africa—and spread as far as China and Java—from the end of the Pliocene epoch to the later Pleistocene: about 1.8-.3 million years ago. There is still disagreement on the subject of the classification, ancestry, and progeny of H. erectus, with two major alternative hypotheses: erectus may be another name for Homo ergaster, and therefore the direct ancestor of later hominids such as Homo heidelbergensis, Homo neanderthalensis, and Homo sapiens; or it may be an Asian species distinct from African ergaster.

H. erectus originally migrated from Africa during the Early Pleistocene, possibly as a result of the operation of the Saharan pump, around 2.0 million years ago, and dispersed throughout much of the Old World. Fossilized remains 1.8 and 1.0 million years old have been found in Africa (e.g., Lake Turkana and Olduvai Gorge), Europe (Georgia, Spain), Indonesia (e.g., Sangiran and Trinil), Vietnam, and China (e.g., Shaanxi).

一般相信是现代人类的袓先。这个种在更新世中期以后的时期都有化石记录，是旧石器时代最早期的人类。比起能人，直立人的脑容积较大，前额没有那么斜，牙齿的体积亦较小。他的特征与现代人的相差不远，其脑容积约达的智人74%，平均高度则约有177.8厘米（5'10"）。

直立人所制作和使用的工具比起他们袓先的都更复杂及多样化。

于1923年在中国北京附近的周口店所发现的北京猿人，以及于1891年在爪哇岛梭罗河附近发现的爪哇人化石，都是直立人的例子。後來歐洲﹑非洲都發現直立猿人化石。

Name 學名﹕ Homo heidelbergensis 海德堡人

Discovered 出土年份﹕1907年

Place 地點﹕ Germany 德國

Age 年份﹕ 40 - 70 萬年前

海德堡人是人屬當中，一種已滅絕的物種，石器技術與屬於直立人的阿舍利（Acheulean）石器相近。可能是歐洲尼安德塔人的直接祖先。而海德堡人的祖先，則可能是歐洲的前人（Homo antecessor）

Homo heidelbergensis ("Heidelberg Man", named after the University of Heidelberg) is an extinct species of the genus Homo which may be the direct ancestor of both Homo neanderthalensis in Europe and Homo sapiens. The best evidence found for these hominin date between 600,000 and 400,000 years ago. H. heidelbergensis stone tool technology was very close to that of the Acheulean tools used by Homo erectus.

參考 References:

http://www.talkorigins.org/faqs/homs/specimen.html

http://en.wikipedia.org/wiki/List_of_primate_and_hominin_fossils

影片