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Yaroslav Afanasyev
Yaroslav Afanasyev

Hominid HOT!


Lucy was found by Donald Johanson and Tom Gray on November 24, 1974, at the site of Hadar in Ethiopia. They had taken a Land Rover out that day to map in another locality. After a long, hot morning of mapping and surveying for fossils, they decided to head back to the vehicle. Johanson suggested taking an alternate route back to the Land Rover, through a nearby gully. Within moments, he spotted a right proximal ulna (forearm bone) and quickly identified it as a hominid. Shortly thereafter, he saw an occipital (skull) bone, then a femur, some ribs, a pelvis, and the lower jaw. Two weeks later, after many hours of excavation, screening, and sorting, several hundred fragments of bone had been recovered, representing 40 percent of a single hominid skeleton.




hominid



The term hominid refers to a member of the zoological family Hominidae. Hominidae encompasses all species originating after the human/African ape ancestral split, leading to and including all species of Australopithecus and Homo. While these species differ in many ways, hominids share a suite of characteristics that define them as a group. The most conspicuous of these traits is bipedal locomotion, or walking upright.


Although several hundred fragments of hominid bone were found at the Lucy site, there was no duplication of bones. A single duplication of even the most modest of bone fragments would have disproved the single skeleton claim, but no such duplication is seen in Lucy. The bones all come from an individual of a single species, a single size, and a single developmental age. In life, she would have stood about three-and-a-half feet tall, and weighed about 60 to 65 pounds.


In Thailand, long-tailed macaque monkeys (shown pounding open oil palm nuts with rocks) inadvertently bash off pieces of stone, raising questions about whether some of the earliest known hominid tools were made on purpose.


Monkeys in southern Thailand use rocks to pound open oil palm nuts, inadvertently shattering stone pieces off their makeshift nutcrackers. These flakes resemble some sharp-edged stone tools presumed to have been created on purpose by ancient hominids, researchers say.


Some differences do exist between macaque and hominid stone flakes, says Proffitt, of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. For instance, many macaque flakes display battering damage on only one side, versus frequent two-sided damage on hominid artifacts.


IN FOR A POUND  A capuchin monkey in Brazil uses a handheld stone to hammer an embedded rock. Researchers say these wild primates unintentionally detach pieces of rock shaped like basic hominid stone tools, raising questions about how toolmaking evolved.


Mr. Taylor writes about the Great Ape Project's campaign to win fundamental rights for all hominids with New Zealand's Animal Welfare Act. While the Act was a significant step in the struggle for hominids' rights, larger steps, including a Nonhuman Hominid Protection Bill, will soon follow.


Nearly 17 years after plucking the fossilized tooth of a new human ancestor from a pebbly desert in Ethiopia, an international team of scientists today (Thursday, Oct. 1) announced their reconstruction of a partial skeleton of the hominid, Ardipithecus ramidus, which they say revolutionizes our understanding of the earliest phase of human evolution.


The female skeleton, nicknamed Ardi, is 4.4 million years old, 1.2 million years older than the skeleton of Lucy, or Australopithecus afarensis, the most famous and, until now, the earliest hominid skeleton ever found. Hominids are all fossil species closer to modern humans than to chimps and bonobos, which are our closest living relatives.


"This is the oldest hominid skeleton on Earth," said Tim White, University of California, Berkeley, professor of integrative biology and one of the co-directors of the Middle Awash Project, a team of 70 scientists that reconstructed the skeleton and other fossils found with it. "This is the most detailed snapshot we have of one of the earliest hominids and of what Africa was like 4.4 million years ago."


Ardi's successor, Lucy, was much better adapted for walking on the ground, suggesting that "hominids became fundamentally terrestrial only at the Australopithecus stage of evolution," he said.


It wasn't until 1 million years after Ardi that hominids like Lucy were able to range extensively into the savannas and develop the robust premolar and molar teeth with thick enamel needed to eat hard seeds and roots. One of these species then started scavenging and using stone tools to butcher larger mammals for meat, "paving the way to the evolution and geographic expansion of Homo, including later elaboration of technology and expansion of the brain," White said.


Purdue's Darryl Granger and Marc Caffee have determined the age of a fossilized skeleton thought to be an Australopithecus – a genus of African hominids from which humanity is thought to have developed – by measuring the radioactivity of the cave sediments in which the skeleton was buried millions of years ago. Their measurement technique, generally used to estimate the age of geological formations such as glaciated valleys and river terraces, has never before been used to date biological fossils.


"By dating the sediments surrounding the fossil skeleton, we have determined that this species reached southern Africa approximately 4 million years ago," said Granger, associate professor of earth and atmospheric sciences in Purdue's School of Science. "If the skeleton is indeed an Australopithecus, as we believe, the findings could mean that these hominids were present in the area far earlier than is generally accepted."


Tracing the development and spread of the hominid species that may have been mankind's ancestor is an arduous process, and it is difficult to determine what happened because precisely dated fossil records are hard to come by. Many such fossils have been found in eastern Africa's Rift Valley, a region that was geologically active when Australopithecus walked the Earth. The abundance of lake sediments and volcanic ash that often surrounds Rift Valley hominid fossils provide good clues as to their age. But there is no such luck with similar fossils from South Africa, a region that also is rich in hominid remains but lacks the definitive geological clues that are present in the Rift Valley.


"Early hominid finds in eastern Africa have traditionally been regarded as the base populations from which all later hominids sprung," said Melissa Remis, associate professor of anthropology in Purdue's School of Liberal Arts. "An earlier hominid find in southern Africa, whatever the species might be, could force a rethinking of what that base population might have been."


Cosmogenic 26 Al and 10 Be burial dates of low-lying fossiliferous breccia in the caves at Sterkfontein, South Africa, show that associated hominid fossils accumulated in the Lower Pliocene. These dates indicate that the skeleton StW 573 and newly discovered specimens from Jacovec Cavern have much the same age: approximately 4 million years. These specimens are thus of an age similar to Australopithecus anamensis from East Africa.


Homo bodoensis would have lived in what is now Ethiopia over 600,000 years ago, with researchers suggesting it replace two other hominid species that have been known to science for over a century.


Homo bodoensis is named for a skull discovered in Bodo D'Ar, Ethiopia in the 1970s, and is thought to date back to the Chibanian Age 600,000 years ago. A new paper proposes this is a new hominid species that is a direct ancestor of Homo sapiens, replacing two other species that the authors consider to be poorly defined.


Early hominids gave way to the australopithecines, a group in which some of our most notable features began to emerge. Australopithecines are a group of species which had small brains and bodies, but were able to walk upright. The most well-known of the group is three-million-year-old specimen of a female Australopithecus afarensis, better known as Lucy.


Homo erectus would last for around 1.5 million years, but also gave rise to other species of hominid. These include Homo antecessor, which is commonly agreed to have branched off before Homo sapiens and Homo neanderthalensis split, but the rest of the period is the subject of intense debate.


This uncertainty is in part due to the description of Homo heidelbergensis based on a single jawbone known as the Mauer mandible. While some scientists believe that enough features of the bone set it apart from other hominids, the researchers in this study have suggested it may not be a species in its own right and is perhaps an early Neanderthal.


In any case, debate over our evolution is set to continue for the foreseeable future. The history of the hominids is by no means certain, but those backing its latest member believe it is here to stay.


A hominid is defined as a member of the Hominidae family and is also known as the 'Great Apes'. Hominids consist of the great apes alive today and those who have gone extinct. Hominids are of the 'primate' order. Members include modern human beings and their closest living primate relatives, including gorillas, orangutans, and chimpanzees, in addition to immediate ancestors.


Hominids are known for being bipedal, which refers to the ability to walk on two legs as opposed to four, and having larger brains. Larger brains relate to higher intelligence and the ability to make and use tools. Modern Homo sapiens are the only members who are bipedal. Bipedalism relates to hominids having an erect posture, or the ability to stand upright. Behaviorally, hominids are able to make and use tools that have specialized functions (e.g. sharp tools for cutting), in addition to being able to communicate via language. The characteristics that define hominids are: 041b061a72


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