Courtesy TmkeeseyMove over Lucy, there is a new hominid in town. Her name is Ardi. One could say Ardipithecus ramidus to be formal. She is a 4.4 million year old ancestor of ours and nearly a million years older than Lucy (Australopithecus afarensis). She is by far the most complete of all the older hominids. Researchers have recovered feet, a leg and pelvis, hands and lower arm, along with the majority of a skull and its teeth. As an added bonus, parts of nearly three dozen more specimens were recovered during the work in the Western Afar Rift of northeastern Ethiopia. This is the same region that gave us Lucy and some early Homo species.
Ardi and her kin walked upright, although their gait was debatably awkward. She retained an opposable toe which could still be used to grasp tree branches, but the remainder of the foot was built for the ground. Like later hominids, the teeth reveal a modern structure and lack enlarged canines. Her pelvis is a mosaic between chimps and Lucy. The Ilium developed short and broad more like a human, while the lower pelvis remains similar to a chimp. Ardi’s skull shows that her brain was still the size of a chimp, being smaller than Lucy’s. Its shape, however was more hominid and had begun evolve more advanced functions.
Unlike Lucy in her savannah habitat, Ardi roamed lush but temperate woodlands. More than 150,000 plant and animal fossils were recovered from the sites. Included are 20 new species of small mammals along with monkeys, antelope, elephants, and multitudes of birds. This was a much different environment than that of the savannah. Theories of the development of bipedalism on the open grasslands will be challenged now because of Ardi and her habitat.
This isn’t a recent find. The original excavations of the search teams started in 1992. But years of field work followed by more than a decade of lab time have really unearthed a mass of data about this time and place in history. 47 diverse researchers from all over the world have included excerpts of their findings about Ardi and her environment. The October 2009 special issue of the publication Science details the discovery and ongoing analysis of this latest find in the continuing quest to uncover the origins of man. With debate well underway, I’m positive we’ll all continue to learn more about our past.
more on Hominid evolution
Courtesy Travis Metcalfe and Ruth Bazinet, Harvard-Smithsonian Center for Astrophysics.
Just in time for Valentine's Day, astronomers discovered a star Feb. 13, 2004 that is thought to be a diamond crystal weighing 10 billion trillion trillion carats.
Click this link to learn more about Lucy, the star made out of diamond.
This Friday the Houston Museum of Natural Science is opening an exhibit called Lucy’s Legacy: The Hidden Treasures of Ethiopia. The exhibit features the 3.18 million-year-old hominid skeleton Lucy, which remains the oldest and most complete adult human ancestor. The exhibit will also feature over 100 artifacts that highlight Ethiopia's rich cultural heritage. The exhibit has generated a lot of media attention, and not just because this will be only the fourth time the fossil hominid has been on display.
Some scientists and researchers fear that involving Lucy in a 6 year North American tour puts the delicate fossil at an unnecessary risk as it travels from Ethiopia, around North America and then back to Ethiopia. Some museums have refused to host the exhibit for this very reason, and several members of the scientific community have spoken out quite openly about their objection to the exhibit and the tour. Some Ethiopian immigrants in Houston are urging a boycott of the exhibit. And the exhibit goes against a 1998 UNESCO resolution, signed by scientists from 20 countries, that says fossils such as Lucy should not be moved outside of the country of origin except for compelling scientific reasons.
The president of the Houston Museum of Natural Science disagrees. “The display of original artifacts is crucial to the educational impact of museum exhibitions. Anyone can make a copy. But the experience of standing before an authentic historical artifact, whether ancient parchments or multi-million-year-old fossils, is a call to the intellect, to discover more about the world and perhaps even more about yourself. The Lucy fossil in particular evokes a strong response from everyone who sees her, and as such, she is the ultimate goodwill ambassador for Ethiopia. Lucy not only validates Ethiopia’s claim as the Cradle of Mankind, she also introduces viewers to the rich cultural heritage that has flourished in Ethiopia over the course of the last 3,000 years, and to the vibrant country that Ethiopia is today.”
Part of the reason Ethiopia agreed to send Lucy on this tour is financial – Ethiopia, one of Africa’s poorest countries, received an undisclosed amount of money to release the fossil for the tour, and also gets a portion of the ticket sales. In addition, government officials hope that people who see the exhibit and who learn not only about Lucy, but also about Ethiopia, will be inspired to visit the country.
What do you think? Does the tour of Lucy put the fossil at unnecessary risk? Or, does the value of exhibiting Lucy and allowing people to learn and be inspired by the fossil outweigh the risk?
An interesting side note: Lucy was named after the Beatle’s song Lucy in the Sky with Diamonds which was playing when the researchers were discussing what to name the fossil. In the Ethiopian language, she is called Dinknesh, which means the wonderful, the fabulous, the precious. And, Ethiopia does have some really interesting stuff – check out the amazing monolithic Church of St. George, for just one example.
The fossil including an entire skull, torso, shoulder blade and various limbs was discovered at Dikaka, some 400 kms northeast of the capital Addis Ababa near the Awash river in the Rift Valley.
"The finding is the most complete hominid skeleton ever found in the world," Zeresenay Alemseged, head of the Paleoanthropological Research Team, told a news conference. Reuters
The fossil has been named "Selam", which means peace in Ethiopia's official Amharic language.
"The Dikika girl stands as one of the major discoveries in the history of palaeoanthropology," research team leader Zeresenay Alemseged said, citing the remarkably well-preserved condition of the bones, the geological age and completeness of the specimen.Cosmos Magazine
The following is the abstract of the original article describing the baby, which was authored by Zeresenay Alemseged, Fred Spoor, William H. Kimbel, René Bobe, Denis Geraads, Denné Reed and Jonathan G. Wynn, and appeared in Nature on September 20, 2006.
"Understanding changes in ontogenetic development is central to the study of human evolution. With the exception of Neanderthals, the growth patterns of fossil hominins have not been studied comprehensively because the fossil record currently lacks specimens that document both cranial and postcranial development at young ontogenetic stages. Here we describe a well-preserved 3.3-million-year-old juvenile partial skeleton of Australopithecus afarensis discovered in the Dikika research area of Ethiopia. The skull of the approximately three-year-old presumed female shows that most features diagnostic of the species are evident even at this early stage of development. The find includes many previously unknown skeletal elements from the Pliocene hominin record, including a hyoid bone that has a typical African ape morphology. The foot and other evidence from the lower limb provide clear evidence for bipedal locomotion, but the gorilla-like scapula and long and curved manual phalanges raise new questions about the importance of arboreal behaviour in the A. afarensis locomotor repertoire."
Additional reading: BBC News
Anthropologists have found the partially intact, 3.3-million-year-old skeleton of a 3-year-old Australopithecus afarensis, the ape-man species represented by "Lucy." Features of the skeleton will add to the scientific debate about whether afarensis, which walked upright, also climbed like an ape.