Ditemukan tengkorak "manusia" tertua

[Zenman1]

Awal Oktober 2009, sejumlah ilmuwan mengumumkan penemuan fosil manusia tertua di dunia. Fosil manusia tertua tersebut ditemukan di Aramis, Ethiopia serta diklasifikasikan ke dalam spesies Ardipithecus ramidus, dengan nama panggilan "Ardi". Berdasarkan penelitian para ilmuwan, Ardi berjenis kelamin wanita dan diperkirakan hidup sekitar 4,4 juta tahun yang lalu. Ardi memiliki volume otak yang terbilang kecil dibandingkan dengan volume otak manusia modern dan berat badan sekitar 50 kilogram. Penemuan Ardi ini memecahkan rekor fosil manusia tertua yang pernah ditemukan. Sebelumnya rekor ini dipegang oleh fosil "Lucy" yang diperkirakan hidup 3,2 juta tahun yang lalu.source ; megindo.net

hmm..benar2 mearik... apakah nenek moyang kita akan terkuak?

[asunn]

mana link sumbernya donk?

[rubymoon]

Move over, Lucy. And kiss the missing link goodbye.

Scientists today announced the discovery of the oldest fossil skeleton of a human ancestor. The find reveals that our forebears underwent a previously unknown stage of evolution more than a million years before Lucy, the iconic early human ancestor specimen that walked the Earth 3.2 million years ago.

The centerpiece of a treasure trove of new fossils, the skeleton—assigned to a species called Ardipithecus ramidus—belonged to a small-brained, 110-pound (50-kilogram) female nicknamed "Ardi." (See pictures of Ardipithecus ramidus.)

The fossil puts to rest the notion, popular since Darwin's time, that a chimpanzee-like missing link—resembling something between humans and today's apes—would eventually be found at the root of the human family tree. Indeed, the new evidence suggests that the study of chimpanzee anatomy and behavior—long used to infer the nature of the earliest human ancestors—is largely irrelevant to understanding our beginnings.

Ardi instead shows an unexpected mix of advanced characteristics and of primitive traits seen in much older apes that were unlike chimps or gorillas (interactive: Ardi's key features). As such, the skeleton offers a window on what the last common ancestor of humans and living apes might have been like.

Announced at joint press conferences in Washington, D.C., and Addis Ababa, Ethiopia, the analysis of the Ardipithecus ramidus bones will be published in a collection of papers tomorrow in a special edition of the journal Science, along with an avalanche of supporting materials published online.

"This find is far more important than Lucy," said Alan Walker, a paleontologist from Pennsylvania State University who was not part of the research. "It shows that the last common ancestor with chimps didn't look like a chimp, or a human, or some funny thing in between." (Related: "Oldest Homo Sapiens Fossils Found, Experts Say" [June 11, 2003].)

Ardi Surrounded by Family

The Ardipithecus ramidus fossils were discovered in Ethiopia's harsh Afar desert at a site called Aramis in the Middle Awash region, just 46 miles (74 kilometers) from where Lucy's species, Australopithecus afarensis, was found in 1974. Radiometric dating of two layers of volcanic ash that tightly sandwiched the fossil deposits revealed that Ardi lived 4.4 million years ago.

Older hominid fossils have been uncovered, including a skull from Chad at least six million years old and some more fragmentary, slightly younger remains from Kenya and nearby in the Middle Awash.

While important, however, none of those earlier fossils are nearly as revealing as the newly announced remains, which in addition to Ardi's partial skeleton include bones representing at least 36 other individuals.

"All of a sudden you've got fingers and toes and arms and legs and heads and teeth," said Tim White of the University of California, Berkeley, who co-directed the work with Berhane Asfaw, a paleoanthropologist and former director of the National Museum of Ethiopia, and Giday WoldeGabriel, a geologist at Los Alamos National Laboratory in New Mexico.

"That allows you to do something you can't do with isolated specimens," White said. "It allows you to do biology."

(Related: Rediscover the earliest Ardipithecus.)

Ardi's Weird Way of Moving

The biggest surprise about Ardipithecus's biology is its bizarre means of moving about.

All previously known hominids—members of our ancestral lineage—walked upright on two legs, like us. But Ardi's feet, pelvis, legs, and hands suggest she was a biped on the ground but a quadruped when moving about in the trees.

Her big toe, for instance, splays out from her foot like an ape's, the better to grasp tree limbs. Unlike a chimpanzee foot, however, Ardipithecus's contains a special small bone inside a tendon, passed down from more primitive ancestors, that keeps the divergent toe more rigid. Combined with modifications to the other toes, the bone would have helped Ardi walk bipedally on the ground, though less efficiently than later hominids like Lucy. The bone was lost in the lineages of chimps and gorillas.

According to the researchers, the pelvis shows a similar mosaic of traits. The large flaring bones of the upper pelvis were positioned so that Ardi could walk on two legs without lurching from side to side like a chimp. But the lower pelvis was built like an ape's, to accommodate huge hind limb muscles used in climbing.

[rubymoon]

Even in the trees, Ardi was nothing like a modern ape, the researchers say.

Modern chimps and gorillas have evolved limb anatomy specialized to climbing vertically up tree trunks, hanging and swinging from branches, and knuckle-walking on the ground.

While these behaviors require very rigid wrist bones, for instance, the wrists and finger joints of Ardipithecus were highly flexible. As a result Ardi would have walked on her palms as she moved about in the trees—more like some primitive fossil apes than like chimps and gorillas.

"What Ardi tells us is there was this vast intermediate stage in our evolution that nobody knew about," said Owen Lovejoy, an anatomist at Kent State University in Ohio, who analyzed Ardi's bones below the neck. "It changes everything."

Against All Odds, Ardi Emerges

The first, fragmentary specimens of Ardipithecus were found at Aramis in 1992 and published in 1994. The skeleton announced today was discovered that same year and excavated with the bones of the other individuals over the next three field seasons. But it took 15 years before the research team could fully analyze and publish the skeleton, because the fossils were in such bad shape.

After Ardi died, her remains apparently were trampled down into mud by hippos and other passing herbivores. Millions of years later, erosion brought the badly crushed and distorted bones back to the surface.

They were so fragile they would turn to dust at a touch. To save the precious fragments, White and colleagues removed the fossils along with their surrounding rock. Then, in a lab in Addis, the researchers carefully tweaked out the bones from the rocky matrix using a needle under a microscope, proceeding "millimeter by submillimeter," as the team puts it in Science. This process alone took several years.

Pieces of the crushed skull were then CT-scanned and digitally fit back together by Gen Suwa, a paleoanthropologist at the University of Tokyo.

In the end, the research team recovered more than 125 pieces of the skeleton, including much of the feet and virtually all of the hands—an extreme rarity among hominid fossils of any age, let alone one so very ancient.

"Finding this skeleton was more than luck," said White. "It was against all odds."

Ardi's World

The team also found some 6,000 animal fossils and other specimens that offer a picture of the world Ardi inhabited: a moist woodland very different from the region's current, parched landscape. In addition to antelope and monkey species associated with forests, the deposits contained forest-dwelling birds and seeds from fig and palm trees.

Wear patterns and isotopes in the hominid teeth suggest a diet that included fruits, nuts, and other forest foods.

If White and his team are right that Ardi walked upright as well as climbed trees, the environmental evidence would seem to strike the death knell for the "savanna hypothesis"—a long-standing notion that our ancestors first stood up in response to their move onto an open grassland environment.

Sex for Food

Some researchers, however, are unconvinced that Ardipithecus was quite so versatile.

"This is a fascinating skeleton, but based on what they present, the evidence for bipedality is limited at best," said William Jungers, an anatomist at Stony Brook University in New York State.

"Divergent big toes are associated with grasping, and this has one of the most divergent big toes you can imagine," Jungers said. "Why would an animal fully adapted to support its weight on its forelimbs in the trees elect to walk bipedally on the ground?"

One provocative answer to that question—originally proposed by Lovejoy in the early 1980s and refined now in light of the Ardipithecus discoveries—attributes the origin of bipedality to another trademark of humankind: monogamous sex.

Virtually all apes and monkeys, especially males, have long upper canine teeth—formidable weapons in fights for mating opportunities.

But Ardipithecus appears to have already embarked on a uniquely human evolutionary path, with canines reduced in size and dramatically "feminized" to a stubby, diamond shape, according to the researchers. Males and female specimens are also close to each other in body size.

Lovejoy sees these changes as part of an epochal shift in social behavior: Instead of fighting for access to females, a male Ardipithecus would supply a "targeted female" and her offspring with gathered foods and gain her sexual loyalty in return.

To keep up his end of the deal, a male needed to have his hands free to carry home the food. Bipedalism may have been a poor way for Ardipithecus to get around, but through its contribution to the "sex for food" contract, it would have been an excellent way to bear more offspring. And in evolution, of course, more offspring is the name of the game (more: "Did Early Humans Start Walking for Sex?").

Two hundred thousand years after Ardipithecus, another species called Australopithecus anamensis appeared in the region. By most accounts, that species soon evolved into Australopithecus afarensis, with a slightly larger brain and a full commitment to a bipedal way of life. Then came early Homo, with its even bigger brain and budding tool use.

Did primitive Ardipithecus undergo some accelerated change in the 200,000 years between it and Australopithecus—and emerge as the ancestor of all later hominids? Or was Ardipithecus a relict species, carrying its quaint mosaic of primitive and advanced traits with it into extinction?

Study co-leader White sees nothing about the skeleton "that would exclude it from ancestral status." But he said more fossils would be needed to fully resolve the issue.

Stony Brook's Jungers added, "These finds are incredibly important, and given the state of preservation of the bones, what they did was nothing short of heroic.

But this is just the beginning of the story."

sumber

http://news.nationalgeographic.com/n...s-ramidus.html

[rubymoon]

Even in the trees, Ardi was nothing like a modern ape, the researchers say.

Modern chimps and gorillas have evolved limb anatomy specialized to climbing vertically up tree trunks, hanging and swinging from branches, and knuckle-walking on the ground.

While these behaviors require very rigid wrist bones, for instance, the wrists and finger joints of Ardipithecus were highly flexible. As a result Ardi would have walked on her palms as she moved about in the trees—more like some primitive fossil apes than like chimps and gorillas.

"What Ardi tells us is there was this vast intermediate stage in our evolution that nobody knew about," said Owen Lovejoy, an anatomist at Kent State University in Ohio, who analyzed Ardi's bones below the neck. "It changes everything."

Against All Odds, Ardi Emerges

The first, fragmentary specimens of Ardipithecus were found at Aramis in 1992 and published in 1994. The skeleton announced today was discovered that same year and excavated with the bones of the other individuals over the next three field seasons. But it took 15 years before the research team could fully analyze and publish the skeleton, because the fossils were in such bad shape.

After Ardi died, her remains apparently were trampled down into mud by hippos and other passing herbivores. Millions of years later, erosion brought the badly crushed and distorted bones back to the surface.

They were so fragile they would turn to dust at a touch. To save the precious fragments, White and colleagues removed the fossils along with their surrounding rock. Then, in a lab in Addis, the researchers carefully tweaked out the bones from the rocky matrix using a needle under a microscope, proceeding "millimeter by submillimeter," as the team puts it in Science. This process alone took several years.

Pieces of the crushed skull were then CT-scanned and digitally fit back together by Gen Suwa, a paleoanthropologist at the University of Tokyo.

In the end, the research team recovered more than 125 pieces of the skeleton, including much of the feet and virtually all of the hands—an extreme rarity among hominid fossils of any age, let alone one so very ancient.

"Finding this skeleton was more than luck," said White. "It was against all odds."

Ardi's World

The team also found some 6,000 animal fossils and other specimens that offer a picture of the world Ardi inhabited: a moist woodland very different from the region's current, parched landscape. In addition to antelope and monkey species associated with forests, the deposits contained forest-dwelling birds and seeds from fig and palm trees.

Wear patterns and isotopes in the hominid teeth suggest a diet that included fruits, nuts, and other forest foods.

If White and his team are right that Ardi walked upright as well as climbed trees, the environmental evidence would seem to strike the death knell for the "savanna hypothesis"—a long-standing notion that our ancestors first stood up in response to their move onto an open grassland environment.

Sex for Food

Some researchers, however, are unconvinced that Ardipithecus was quite so versatile.

"This is a fascinating skeleton, but based on what they present, the evidence for bipedality is limited at best," said William Jungers, an anatomist at Stony Brook University in New York State.

"Divergent big toes are associated with grasping, and this has one of the most divergent big toes you can imagine," Jungers said. "Why would an animal fully adapted to support its weight on its forelimbs in the trees elect to walk bipedally on the ground?"

One provocative answer to that question—originally proposed by Lovejoy in the early 1980s and refined now in light of the Ardipithecus discoveries—attributes the origin of bipedality to another trademark of humankind: monogamous sex.

Virtually all apes and monkeys, especially males, have long upper canine teeth—formidable weapons in fights for mating opportunities.

But Ardipithecus appears to have already embarked on a uniquely human evolutionary path, with canines reduced in size and dramatically "feminized" to a stubby, diamond shape, according to the researchers. Males and female specimens are also close to each other in body size.

Lovejoy sees these changes as part of an epochal shift in social behavior: Instead of fighting for access to females, a male Ardipithecus would supply a "targeted female" and her offspring with gathered foods and gain her sexual loyalty in return.

To keep up his end of the deal, a male needed to have his hands free to carry home the food. Bipedalism may have been a poor way for Ardipithecus to get around, but through its contribution to the "sex for food" contract, it would have been an excellent way to bear more offspring. And in evolution, of course, more offspring is the name of the game (more: "Did Early Humans Start Walking for Sex?").

Two hundred thousand years after Ardipithecus, another species called Australopithecus anamensis appeared in the region. By most accounts, that species soon evolved into Australopithecus afarensis, with a slightly larger brain and a full commitment to a bipedal way of life. Then came early Homo, with its even bigger brain and budding tool use.

Did primitive Ardipithecus undergo some accelerated change in the 200,000 years between it and Australopithecus—and emerge as the ancestor of all later hominids? Or was Ardipithecus a relict species, carrying its quaint mosaic of primitive and advanced traits with it into extinction?

Study co-leader White sees nothing about the skeleton "that would exclude it from ancestral status." But he said more fossils would be needed to fully resolve the issue.

Stony Brook's Jungers added, "These finds are incredibly important, and given the state of preservation of the bones, what they did was nothing short of heroic.

But this is just the beginning of the story."

sumber

http://news.nationalgeographic.com/n...s-ramidus.html

[チャン]

Wuaduh.. Inggrisan semua..

Kok bisa ya manusia memprediksikan Fosil berjuta2 tahun yang lalu.. Sesuatu yang tidak masuk akal...

Apakah hampir sama dengan Pithecantropus Erectus..?

[Szayel]

Itungannya diliat dari tes kimia kepada fosil n kedalaman tempat ditemukannya
Begitu seinget gue dijelasinnya pas Geografi kelas 1 SMA

[TumTum]

shun, cari artikel yg bagusnya susah,tapi garis besarnya spt ini:

http://romdhoni.staff.gunadarma.ac.i...Kimia+Inti.pdf

Umur sisa mahluk hidup (fosil) dapat ditentukan dengan mengukur radioaktifitas atau laju
peluruhan C14 pada sisa mahluk hidup dan dibandingkan dengan laju peluruhan C14 pada mahluk
hidup sekarang (» laju peluruhan C14 semula). Penggunaan radiasi C14 untuk menentukan umur
sisa mahluk hidup ini disebut Radiokarbon Dating.
Misal radioaktifitas C14 pada fosil sisa tumbuhan (= A) = 10 peluruhan permenit pergram
C14, Radioaktifitas C14 pada tumbuhan sekarang (= Ao) = 50 peluruhan permenit pergram C14.
Waktu paruh C14 = 5 730 tahun. Maka umur fosil (= t) dicari dengan persamaan:

[rubymoon]

In itu opo toh?

duh

[チャン]

Originally Posted by Benodhi

Itungannya diliat dari tes kimia kepada fosil n kedalaman tempat ditemukannya
Begitu seinget gue dijelasinnya pas Geografi kelas 1 SMA

Tapi..seluruh Fosil apa harus utuh..misal ditemukan cuman bagian kepalanya.. Apa untuk tangan dan kakinya tidak termasuk hitungan.. ?

Originally Posted by TumTum

shun, cari artikel yg bagusnya susah,tapi garis besarnya spt ini:

http://romdhoni.staff.gunadarma.ac.i...Kimia+Inti.pdf

Umur sisa mahluk hidup (fosil) dapat ditentukan dengan mengukur radioaktifitas atau laju
peluruhan C14 pada sisa mahluk hidup dan dibandingkan dengan laju peluruhan C14 pada mahluk
hidup sekarang (» laju peluruhan C14 semula). Penggunaan radiasi C14 untuk menentukan umur
sisa mahluk hidup ini disebut Radiokarbon Dating.
Misal radioaktifitas C14 pada fosil sisa tumbuhan (= A) = 10 peluruhan permenit pergram
C14, Radioaktifitas C14 pada tumbuhan sekarang (= Ao) = 50 peluruhan permenit pergram C14.
Waktu paruh C14 = 5 730 tahun. Maka umur fosil (= t) dicari dengan persamaan:

Weeehh.... pake rumus Logaritma.. tetep ga ngerti Tum.. Puyeng...

[jeanvaljean]

Originally Posted by チャン

Tapi..seluruh Fosil apa harus utuh..misal ditemukan cuman bagian kepalanya.. Apa untuk tangan dan kakinya tidak termasuk hitungan.. ?

Usia semua bagiannya kan bakal sama, karena dari individu yang sama.

[TumTum]

Originally Posted by rubymoon

In itu opo toh?

duh

ln itu dibaca lon.. dlm logaritma kan a log b (posisi a itu diatas) nah kalo a = n yaitu bilangan alam,maka log bisa berubah jd ln... (kalo salah mohon dikoreksi yah... )

[rubymoon]

jd inget pithecan tropus javanicus (kalo bener tulisannya)
ditemukan di jawa oleh

Pithechanthropus Wongdeso Javanicus
xxpedia ensiklopedia bebas berbahasa Indonesia.
Langsung ke: navigasi, cari

Merupakan salah satu Manusia tertua di Indonesia, Pithecanthropus Wongdeso Javanicus sudah memiliki peradaban moderen diantaranya:

* Bertani
* Membuat Gubuk
* Diperkirakan Kapur sirih berasal dasri kebudayaan mereka
* Musik Rock
* Laptop
* Seni menembak ludah

ampun

[rubymoon]

A European Ancestor to African Great Apes and Humans?



While the spotlight of the day might rest on the newly announced Miocene ape, Anoiapithecus brevirostris, another important early great ape is sitting in the shadows. It is Rudapithecus hungaricus, which, along with Dryopithecus and Anoiapithecus, is considered by some to be related to living great apes. Rudapithecus may be the closest we have yet come to finding the ancestor of African great apes and humans. All of these fossil apes were found in Europe.

Rudapithecus, nicknamed Gabi, was discovered through the work of National Geographic grantee David Begun of the University of Toronto and his collaborator at the Geological Institute in Budapest, László Kordos. The fossil is known from an almost complete skull and mandible (the only such set from a Miocene ape in Europe) and some skeletal parts, including a pelvis, two thigh bones, and wrist bones.

Begun has long championed the idea that the ancestors of African apes evolved in Eurasia. In his view, Anoiapithecus adds more evidence to support his hypothesis. Begun suggests, however, that Anoiapithecus is very similar to Dryopithecus, and may not deserve the status of a new genus. Furthermore, while Anoiapithecus, which is 12 million years old, is presented as ancestral to all great apes, Rudapithecus, which is 10 million years old, is ancestral only to a subfamily of great apes that excludes orangutans but includes humans. Thus Rudapithecus is key to the argument that the earliest members of the African great ape lineage we evolved from appeared first in Europe before returning to Africa.

Scientists who disagree with Begun discount the significance of the Miocene apes of Europe, including Rudapithecus, because they think African great apes evolved in Africa. Unfortunately, there is a gap in the fossil record in Africa between Miocene apes living there before 14 million years ago and the appearance of hominins in Africa between 7 and 5 million years ago. So there is little fossil evidence to support the view that great apes evolved from earlier African apes in Africa. To remedy this paleontologists are scouring Africa for fossil apes that lived there between 12 and 5 million years ago, when the lineages of gorillas, chimps, and humans diverged. And in Hungary, Begun and Kordos will keep searching for more remains of Rudapithecus, hoping they will provide further evidence for their "Out of Europe" hypothesis. They are confident that more of Gabi's skeleton remains buried at the site, which is near Rudabánya. National Geographic is funding their continued excavations there.

The fossil skull of the Rudapithecus specimen nicknamed Gabi (below) is remarkably well preserved and shares features with gorillas, such as short lower parts of the face. Photo © David Begun.



sumber

http://blogs.ngm.com/blog_central/20...e-artwork.html

[チャン]

Originally Posted by rubymoon

jd inget pithecan tropus javanicus (kalo bener tulisannya)
ditemukan di jawa oleh

Pithechanthropus Wongdeso Javanicus
xxpedia ensiklopedia bebas berbahasa Indonesia.
Langsung ke: navigasi, cari

Merupakan salah satu Manusia tertua di Indonesia, Pithecanthropus Wongdeso Javanicus sudah memiliki peradaban moderen diantaranya:

* Bertani
* Membuat Gubuk
* Diperkirakan Kapur sirih berasal dasri kebudayaan mereka
* Musik Rock
* Laptop
* Seni menembak ludah

ampun

Laptop


apa sudah ada di jaman itu Fe ?