Homo erectus “Homo erectus” had a considerably larger brain than “Homo habilis, its predecessor. It fashioned more advanced tools (double-edged, teardrop-shaped "hand axes" and "cleavers" ) and controlled fire (based on the discovery of charcoal with erectus fossils). Better foraging and hunting skills, allowed it to exploit its environment better than “Homo habilis” Nickname: Peking Man, Java Man. “Homo erectus” lived for 1.3 million years and spread from Africa to Europe and Asia. Paleontologist Alan Walker told National Geographic, “Homo erectus “ "was the velociraptor of its day. If you could look one in the eyes, you wouldn't want to. It might appear to be human, but you wouldn't connect. You'd be prey."
Geologic Age 1.8 million years to 250,000 years ago. Homo erectus “ lived at the same time as “Homo habilis “ and “Homo rudolfensis” and perhaps Neanderthals. Linkage to Modern Man: Regarded as a direct ancestor of modern man, May have had primitive language skills. Discovery Sites: Africa and Asia. Most “Homo erectus “ fossils have been found in eastern Africa but specimens have also been found in southern Africa, Algeria, Morocco, China and Java.
Homo erectus was the first of our relatives to have body proportions like a modern human. It may have been the first to harness fire and cook food. L.V. Anderson wrote on Slate.com: It’s thought that both Neanderthals and Homo sapiens evolved from H. erectus, with Neanderthals emerging about 600,000 years ago (and going extinct around 30,000 years ago) and modern humans emerging around 200,000 years ago (and still going strong). Neanderthals were shorter and had more complex societies than H. erectus, and they’re thought to have been at least as large-brained as modern humans, but their facial features protruded a little more and their bodies were stouter than ours. It’s thought that Neanderthals died out from competing, fighting, or interbreeding with H. sapiens.” [Source: L.V. Anderson, Slate.com, October 5, 2012 \~/]
Websites and Resources on Hominins and Human Origins: Smithsonian Human Origins Program humanorigins.si.edu ; Institute of Human Origins iho.asu.edu ; Becoming Human University of Arizona site becominghuman.org ; Talk Origins Index talkorigins.org/origins ; Last updated 2006. Hall of Human Origins American Museum of Natural History amnh.org/exhibitions ; Wikipedia article on Human Evolution Wikipedia ; Human Evolution Images evolution-textbook.org; Hominin Species talkorigins.org ; Paleoanthropology Links talkorigins.org ; Britannica Human Evolution britannica.com ; Human Evolution handprint.com ; National Geographic Map of Human Migrations genographic.nationalgeographic.com ; Humin Origins Washington State University wsu.edu/gened/learn-modules ; University of California Museum of Anthropology ucmp.berkeley.edu; BBC The evolution of man" bbc.co.uk/sn/prehistoric_life; "Bones, Stones and Genes: The Origin of Modern Humans" (Video lecture series). Howard Hughes Medical Institute.; Human Evolution Timeline ArchaeologyInfo.com ; Walking with Cavemen (BBC) bbc.co.uk/sn/prehistoric_life ; PBS Evolution: Humans pbs.org/wgbh/evolution/humans; PBS: Human Evolution Library www.pbs.org/wgbh/evolution/library; Human Evolution: you try it, from PBS pbs.org/wgbh/aso/tryit/evolution; John Hawks' Anthropology Weblog johnhawks.net/ ; New Scientist: Human Evolution newscientist.com/article-topic/human-evolution; Fossil Sites and Organizations: The Paleoanthropology Society paleoanthro.org; Institute of Human Origins (Don Johanson's organization) iho.asu.edu/; The Leakey Foundation leakeyfoundation.org; The Stone Age Institute stoneageinstitute.org; The Bradshaw Foundation bradshawfoundation.com ; Turkana Basin Institute turkanabasin.org; Koobi Fora Research Project kfrp.com; Maropeng Cradle of Humankind, South Africa maropeng.co.za ; Blombus Cave Project web.archive.org/web; Journals: Journal of Human Evolution journals.elsevier.com/; American Journal of Physical Anthropology onlinelibrary.wiley.com; Evolutionary Anthropology onlinelibrary.wiley.com; Comptes Rendus Palevol journals.elsevier.com/ ; PaleoAnthropology paleoanthro.org.
Homo Erectus Size
Homo erectus Size: The tallest hominin species until modern man. The body looked almost like a modern human. males: 5 feet 10 inches tall, 139 pounds; females: 5 feet 3 inches tall, 117 pounds. “Homo erectus” was considerably larger than its forebears. Scientists speculate that the reason for this is that they ate more meat.
Brain Size: 800 to 1000 cubic centimeters. Enlarged over the years from the size of a one -year-old infant to that of a 14-year-old boy (about three-fourths the size of a modern adult human brain). A 1.2-million-year-old skull from Olduvai Gorge had a cranial capacity of 1,000 cubic centimeters, compared to 1,350 cubic centimeters for a modern human and 390 cubic centimeters for a chimp.
In an August 2007 article in Nature, Maeve Leakey of the Koobi Fora Research Project announced her team had found a well-preserved, 1.55-million-year-old skull of a young adult “Homo erectus “ east of Lake Turkana in Kenya. The skull was the smallest ever found of the species which indicated that “Homo erectus” may not have been as advanced as had been previously thought. The finding does not challenge the theory that “Homo erectus” are the direct ancestors of modern humans. But does make one step back and wonder could such an advanced creature such a modern man evolved from such a diminutive, small-brained creature such as “Homo erectus”.
The finding shows that if nothing else there is great degree of variation in the size of “Homo erectus” specimens. The fossils were found several years before but extra care was taken identifying the species and dating the fossils, which was done from volcanic ash deposits.
Susan Anton, an anthropologist at New York University and one of the authors of the discovery, said that the variation in sizes is particularly noticeable between males and females and the finding seems to suggest that sexual dimorphism was present among “Homo erectus”. Daniel Leiberman, a Harvard anthropology professor, told the New York Times, “the small skull has got to be female, and my guess is all the previous erectus we have found turn out to be male.” If this turns out to be true then it could turn out that “Homo erectus” had a gorilla-like sex life like that of “Australopithecus robustus” (See Australopithecus robustus).
Homo Erectus Skull and Body Features
Homo erectus skull Skull Features: Thickest skull of all homonids: long and low and resembling a "partially deflated football." More similar to predecessors than modern man, no chin, protruding jaw, low and heavy braincase, thick browridges, and backward sloping forehead. Compared to its predecessors there was a reduced size and projection of the face, including much smaller teeth and jaws than those of Paranthropus and loss of the skull crest. A bony nasal bridge suggests a nose that projected like ours. “Homo erectus” was the first hominin to have asymmetrical brains like modern humans. The frontal lobe, where complex thinking takes place in modern humans, was relatively underdeveloped. The small hole in vertebrae probably meant that not enough information was transferred from the brain to the lungs, neck and mouth to make speech possible.
Body Features: Body similar to modern humans. It had long-limbed proportions common in tropical people. Tall, lean and slim hipped, it had a rib cage virtually identical to that of modern humans and strong bones able to withstand the wear and tear of a hard life on the savannah.
“Homo erectus was about five to six feet tall. Its narrow pelvis, changes in the hips and arched foot meant that it could move more efficiently and quickly on two legs than even modern humans. The legs grew longer relative to the arms, indicating more efficient walking and perhaps running,It almost certainly could run like modern humans. It's large size meant it had a large surface area able to dissipate tropical heat through sweating.
Homo erectus's teeth and jaws were smaller and less powerful than its predecessors because meat, its main food source, is easier to chew than coarse vegetation and nuts eaten by its predecessors. It was most likely a hunter well adapted for the open grasslands of savannah Africa.
Homo erectus's skull was surprisingly thick — so thick in fact that some fossil hunters have mistaken it for a turtle shell. The top and sides of the cranium had thick, bony walls and a low, a wide profile, and in many ways resembled a bicycle helmet. Scientists have long wondered why the skull was so helmet-like: it didn’t offer much protection against predators that killed mostly by bites to the neck. Recently it has been suggested that a thick skull offered protection against other homo erectus, namely males who battled each other, perhaps by bashing each other with stone tools aimed at the head. On some erectus skulls there is evidence that suggests the head may have been struck with repeated heavy blows.
Homo Erectus Tools
tools found at
Konso-Gardula, Ethiopia Hand axes are usually associated with “Homo erectus”. Ones found at Konso-Gardula, Ethiopia are believed to be between 1.37 and 1.7 million year old. Describing a primitive 1.5- to 1.7-million-year-old ax, Ethiopian archaeologist Yonas Beyene told National Geographic, "You don't see much refinement here. They've only been knapped away a few flakes to make the edge sharp." After displaying a beautifully-crafted ax from a perhaps a 100,000 year later he said, "See how refined and straight the cutting edge has become. It was an artform for them. It wasn't just for cutting. Making these is time-consuming working."
Thousands of primitive hand 1.5-million- to 1.4-million-year-old hand axes have been Olduvai Gorge, Tanzania and Ubeidya, Israel. Carefully-crafted, sophisticated 780,000-year-old hand axes have been unearthed in Olorgesaile, near the Kenya and Tanzania border. Scientists believe they were used to butcher, dismember and deflesh large animals like elephants.
Sophisticated “ Homo erectus “ teardrop-shaped stone axes that fit snugly in the hand and had a sharp edged created by careful shearing of the rock on both sides. The tool could be used to cut, smash and beat.
Big symmetrical hand axes, known as Acheulan tools, endured for more than 1 million years little changed from the earliest versions found. Since few advances were made one anthropologists described the period in which “Homo erectus” lived as a time of “almost unimaginable monotony.” Acheulan tools are named after 300,000-year-old hand axes and other tools found in St. Acheul, France.
Java Man Java man was discovered by Eugene DuBois, a young Dutch military doctor, who came to Java in 1887 with the sole purpose of finding the "missing link" between humans and apes after hearing about discoveries of ancient human bones (which later turned out to belong to modern man) near the Javanese village of Wajak, near Tulung Agung, in eastern Java.
With the help of 50 East Indian convict laborers, he discovered a skull cap and thighbone — that clearly didn't belong to an ape — along the banks of the Sunngai Bengawan Solo River in 1891. After measuring the cranial capacity of the skull with mustard seeds, Dubois realized that the creature was more of an "ape-like man" than a "man-like ape." Dubois dubbed the find “Pithecanthropus erectus”, or "upright ape-man,” which is now regarded as an example of “Homo erectus”.
The discovery of Java Man was the first major hominin find, and helped launch the study of early man. His finding created such a storm of controversy that Dubois felt compelled to re-bury the bones for 30 years to protect them.
DuBois was the student of Ernst Haeckel, a Charles Darwin disciple who wrote “History of Natural Creation” (1947), which advocated the Darwinian view of evolution and speculated about primitive human beings. Dubois came to Indonesia with the ambition of confirming Haekel’s theories. He died a bitter man because his discoveries he felt weren't taken seriously.
After Dubois other Homo erectus bones were unearthed in Java. In the 1930s, Ralph von Koenigswald found fossils, dated at be 1 million years old, near the village of Sangiran, along the Solo river, 15 kilometers north of Solo. Other fossils have been found along the Sungai Bengawan Solo in Central and East Java and near Pacitan in East Java’s south coast. In 1936 a skull of a child was found at Perning neat Mojokerto.
Book: “Java Man” by Carl Swisher, Garniss Curtis and Roger Lewis.
Redating Java Man
Java Man skull In 1994, Berkeley scientist Carl Swisher shook up the paleontology world when he redated the volcanic sediments of a “Homo erectus” Java man skull using a sophisticated mass spectrometer — that accurately measure the radioactive decay rates of potassium and argon found in volcanic sediments — and found that the skull was 1.8 million years old instead of 1 million years old as was previously reported. His discovery placed “Homo erectus” in Indonesia, some 800,000 years before it was thought to have left Africa.
Critics of Swisher's findings say that the skull may have been washed into older sediments. In response his critics Swisher has dated numerous sediment samples taken where hominin fossils were found in Indonesia and found that most of the sediments were 1.6 million years old or older.
In addition to that “Homo erectus” fossils found at site called Ngandong in Indonesia, previously thought to be between 100,000 and 300,000 years old, were dated in strata between 27,000 and 57,000 years old. This implies that “Homo erectus” live much longer than anyone thought and “Homo erectus” and “Homo sapiens” existed at the same time on Java. Many scientists are skeptical about the Ngandong dates.
Hominins Cross the Wallace Line
Stone flake tools, found near a stegodons (ancient elephant), dated to 840,000 years ago, were found in the Soa Basin on Indonesian island of Flores. The tools are thought to have belonged to Homo Erectus. They only way to get the island is by boat, through sometimes turbulent seas, which implies “Homo erectus” built seaworthy rafts or some other kind of vessel. This discovery is regarded with caution but may mean that early hominins may have cross the Wallace Line 650,000 years earlier than previously thought.
During several ice ages when sea levels dropped Indonesia was connected to the Asian continent. It is believed that Homo erectus arrived in Indonesia during one of the ice ages.
The Wallace Line is an invisible biological barrier described by and named after the British naturalist Alfred Russell Wallace. Running along the water between the Indonesia islands of Bali and Lombok and between Borneo and Sulawesi, it separates the species found in Australia, New Guinea and the eastern islands of Indonesia from those found in western Indonesia, the Philippines and the Southeast Asia.
Because of the Wallace Line Asian animals such as elephants, orangutans and tigers never ventured further east than Bali, and Australian animals such as kangaroos, emus, cassowaries, wallabies and cockatoos never made it to Asia. Animals from both continents are found in some parts of Indonesia.
-Fossil teeth of Indonesian pigs at Java Man site
The first people to cross the Wallace line from Bali to Lombok, Indonesia, scientists speculate, arrived in a kind of paradise free of predators and competitors. Crustaceans and mollusks could be collected from tidal flats and pygmy elephants unafraid of man could be easily hunted. When food supplies ran low, the early inhabitants moved on to the next island, and the next until the finally reached Australia.
The discovery of the Hobbits in Flores is thought to confirm that Homo Erectus crossed the Wallace Line. See Hobbits.
"Peking Man" refers to a collection of six complete or nearly complete skulls, 14 cranial fragments, six facial fragments, 15 jawbones, 157 teeth, one collarbone, three upper arms, one wrist, seven thighbones, and one shinbone found in caves and a quarry outside of Peking (Beijing). It is believed the remains came from 40 individuals of both sexes that lived during a 200,000 year period. Peking Man is categorized as a member of the hominin species Homo erectus as is Java Man.
The Peking Man bones are the largest collection of hominin bones ever found at one site and were the first evidence that early man reached China. It was first thought the bones were between 200,000 and 300,000 years old. Now it is believed that they are 400,000 to 670,000 years old based on dating the sediments in which the fossils were found. No chemical tests or research were ever done on the bones before they mysteriously disappeared at the beginning of World War II.
"Peking Man" was found in quarry and some caves near the village of Zhoukoudian, 30 miles southwest of Beijing. The first fossils found in the quarry were dug up by villagers who sold them as "dragon bones" to a local folk medicine shop. In the 1920s, a Swedish geologist became fascinated with a human-like tooth believed to be two million years old in the collection of a German physician who hunted fossils in China. He began his own search for fossils, beginning in Beijing and was led by a local farmer to Zhoukoudian, which means Dragon Bone Hill.
Foreign and Chinese archeologists launched a major excavation at Zhoukoudian. The digging intensified when a human molar was found. In December 1929 a complete skullcap was found imbedded in a rock face by a Chinese archeologist clinging to a rope. The skull was presented to the world as the "missing link" between man and monkeys.
Excavations continued through the 1930s and more bones were found along with stone tools and evidence of the use of fire. But before the bones had a chance to be carefully examined, the Japanese invaded China and World War II broke out.
Peking Man and Fire
The oldest largely accepted evidence of fire used by an ancestor of modern man is a group of burned animals bones found among remains of Homo erectus in the same caves in Zhoukoudian, China where Peking man was found. The burned bones have been dated to be about 500,000 years old. In Europe, there is evidence of fire that is 400,000 years old.
Homo erectus is believed to have learned to control fire about one million years ago. Some scientist speculate that early hominins gathered smoldering wood from lighting-ignited fires and used it to cook meat. Some scientists suggest that fire may have been tamed as early as 1.8 million years ago based on the theory that Homo erectus needed to cook food such as tough meat, tubers and roots to make them edible. Cooked food is more edible and easy to digest. It takes a chimpanzee about an hour to absorb 400 calories from eating raw meat. By contrast it takes a modern human only a couple minutes to wolf down the same amount of calories in a sandwich.
There is some evidence of ritual cannibalism in Peking man. Peking Man skulls had been smashed at the base, possibly by other Peking men to gain access to the brains, a practice common among cannibals.
"Turkana Boy" is a nearly complete skeleton and skull from a 12-year-old boy that lived 1.54 million years ago and was discovered in 1984 near the shores of Lake Turkana not far from Nariokotome, Kenya. Some scientists think he is “Homo erectus”. Others regard him as distinctive enough to be regarded as a separate species — “homo ergaster”. Turkana Boy was about 5-foot, 3-inches tall when he died and probably would have reached a height of about six feet if he reached maturity. Turkana boy is the most complete skeleton of a hominin more than a million years old.
“Homo ergaster “ is a hominin species that lived between 1.8 million and 1.4 million years ago. Many scientists regard “Homo ergaster “ as a member of the “Homo erectus “ species. Skull Features: smaller jaws and a more projecting nose than earlier Homos. Body Features: Arm and leg proportions more similar to modern man. Discovery Site: Koobi Fora at Lake Turkana, Kenya.
Homo Erectus Footprints Reveal They Walked Like Modern Humans
Turkana boy In the mid 2010s, researchers from the Max Planck Institute for Evolutionary Anthropology in Leipzig discovered multiple assemblages of 1.5-million-year-old Homo erectus footprints in northern Kenya that provide unique opportunities to understand locomotor patterns and group structure through a form of data that directly records these dynamic behaviours. Novel analytical techniques used by the Max Planck Institute and an international team of collaborators, have demonstrated that these H. erectus footprints preserve evidence of a modern human style of walking and a group structure that is consistent with human-like social behaviours. [Source:Max-Planck-Gesellschaft, Science Daily,July 12, 2016]
Max-Planck-Gesellschaft reported: “Fossil bones and stone tools can tell us a lot about human evolution, but certain dynamic behaviours of our fossil ancestors — things like how they moved and how individuals interacted with one another — are incredibly difficult to deduce from these traditional forms of paleoanthropological data. Habitual bipedal locomotion is a defining feature of modern humans compared with other primates, and the evolution of this behaviour in our clade would have had profound effects on the biologies of our fossil ancestors and relatives. However, there has been much debate over when and how a human-like bipedal gait first emerged in the hominin clade, largely because of disagreements over how to indirectly infer biomechanics from skeletal morphologies. Likewise, certain aspects of group structure and social behaviour distinguish humans from other primates and almost certainly emerged through major evolutionary events, yet there has been no consensus on how to detect aspects of group behaviour in the fossil or archaeological records.
“In 2009, a set of 1.5-million-year-old hominin footprints was discovered at a site near the town of Ileret, Kenya. Continued work in this region by scientists from the Max Planck Institute for Evolutionary Anthropology, and an international team of collaborators, has revealed a hominin trace fossil discovery of unprecedented scale for this time period — five distinct sites that preserve a total of 97 tracks created by at least 20 different presumed Homo erectus individuals. Using an experimental approach, the researchers have found that the shapes of these footprints are indistinguishable from those of modern habitually barefoot people, most likely reflecting similar foot anatomies and similar foot mechanics. "Our analyses of these footprints provide some of the only direct evidence to support the common assumption that at least one of our fossil relatives at 1.5 million years ago walked in much the same way as we do today," says Kevin Hatala, of the Max Planck Institute for Evolutionary Anthropology and The George Washington University.
Based on experimentally derived estimates of body mass from the Ileret hominin tracks, the researchers have also inferred the sexes of the multiple individuals who walked across footprint surfaces and, for the two most expansive excavated surfaces, developed hypotheses regarding the structure of these H. erectus groups. At each of these sites there is evidence of several adult males, implying some level of tolerance and possibly cooperation between them. Cooperation between males underlies many of the social behaviours that distinguish modern humans from other primates. "It isn't shocking that we find evidence of mutual tolerance and perhaps cooperation between males in a hominin that lived 1.5 million years ago, especially Homo erectus, but this is our first chance to see what appears to be a direct glimpse of this behavioural dynamic in deep time," says Hatala.
Journal Reference: Kevin G. Hatala, Neil T. Roach, Kelly R. Ostrofsky, Roshna E. Wunderlich, Heather L. Dingwall, Brian A. Villmoare, David J. Green, John W. K. Harris, David R. Braun, Brian G. Richmond. Footprints reveal direct evidence of group behavior and locomotion in Homo erectus. Scientific Reports, 2016; 6: 28766 DOI: 10.1038/srep28766
Endurance Running Key Part of Human Evolution
Many scientists believe large brains developed relatively rapidly hand in hand with scavenging and endurance runners. Our upright posture, relatively hairless skin with sweat glands allow us to keep cool in hot conditions. Our large buttocks muscles and elastic tendons allow us to run long distance more efficiently than other animals. [Source: Abraham Rinquist, Listverse, September 16, 2016]
According to the “endurance running hypothesis,” first proposed in the early 2000s, long-distance running played a critical role in the development of our current upright body form. Researchers have suggested that our early ancestors were good endurance runners — presumably using the skill to efficiently cover large distances in search of food, water and cover and maybe methodically chase down prey and — and this characteristic left an evolutionary mark on many parts of our bodies, including our leg joints and feet and even our heads and buttocks. [Source: Michael Hopkin, Nature, November 17, 2004 ||*||]
Michael Hopkin wrote in Nature: “Early humans may have taken up running around 2 million years ago, after our ancestors began standing upright on the African savannah, suggest Dennis Bramble of the University of Utah and Daniel Lieberman of Harvard University. As a result, evolution would have favoured certain body characteristics, such as wide, sturdy knee-joints. The theory may explain why, thousands of years later, so many people are able to cover the full 42 kilometres of a marathon, the researchers add. And it may provide an answer to the question of why other primates do not share this ability. ||*||
“Our poor sprinting prowess has given rise to the idea that our bodies are adapted for walking, not running, says Lieberman. Even the fastest sprinters reach speeds of only about 10 metres per second, compared with the 30 metres per second of a cheetah. But over longer distances our performance is much more respectable: horses galloping long distances average about 6 metres per second, which is slower than a top-class human runner. "Everyone says humans are bad runners, because when you think of running you tend to think of sprinting," he adds. "There's no question we're appalling sprinters, but we're quite good at endurance running."||*||
“How did we get so good at running? Scavenging is the best answer, Lieberman suggests. Our savannah ancestors would have been in competition with hyenas, who are also good long-distance runners, to get to the site of a big kill and pick over the remains. "You could see a flock of vultures on the horizon and just take off towards them," he says. Or perhaps early humans used their endurance simply to chase prey to exhaustion. ||*||
“The theory makes sense of a raft of human characteristics, Bramble and Lieberman write in this week's Nature1. Not only do we have springy Achilles tendons and stout leg-joints, our hairlessness and tendency to sweat make us very good at dissipating heat. Running may even have improved our balance, says Fred Spoor, who studies human evolution at University College London. "Running requires a lot of delicate coordination: your legs are off the ground and you need to coordinate your eyes to see where your foot will land," he says. ||*||
Many animals keep their balance with the aid of semicircular canals in the inner ear, which are filled with fluid that acts as an acceleration detector. These structures are unusually large in both modern humans and our evolutionary cousin Homo erectus and this shows, says Spoor, that they might have helped primitive runners stay on their feet. In fact, running seems to be the only reason that we have prominent buttocks, says Lieberman. He has measured the activity of the gluteus maximus muscle in volunteers during a walk and a jog. "When they walk their glutes barely fire up," he says. "But when they run it goes like billy-o." It remains to be seen how the theory will be received, says Spoor. If correct, it means that the genus Homo is unique among primates in its running ability. But some experts maintain that there is nothing special about human locomotion, and what separates us from other apes is simply our outsized brains. “ ||*||
Anatomical Features That Made Humans Good Runners
Pigs are terrible runners. They lack the so-called nuchal ligament, an elastic band of tissue that runs from a ridge on the base of the skull to the spine. It keeps an animal’s head steady when it runs. Horses, dogs, cheetahs, and other good runners have such a ligament. William J. Cromie of the Harvard News wrote: “Traces of a nuchal ridge can be found in skulls millions of years old, so the next step was to check the fossils of early humans at the renowned Peabody Museum. It turns out that neither the earliest prehumans or the chimps that are their nearest relatives have a nuchal ridge. But some later-evolving hominins did. Known as Homo erectus, these tall, upright people were similar to modern humans. From the neck down, we would identify with them. [Source: William J. Cromie, Harvard News, November 18, 2004 ^=^]
“The meaning of this discrepancy struck Bramble and Lieberman in the head, so to speak. Chimps and the stooped predecessors of H. erectus, known as australopithecines, spent much of their time in the trees and had no good reason to run around much. With their long arms and more apelike anatomy, they walked or climbed around Africa from about 6 million to 2 million years ago. Two or 3 million years ago, when H. erectus came out of the trees and roamed the grassy savannas of Africa, running became a very handy thing for getting food. Four-legged animals can move like missiles, but tall, two-legged creatures move like pogo sticks. To be fast and steady, you need a head that oscillates up and down, but doesn’t pitch back and forth or bobble from side to side. ^=^
The nuchal ligament is one of several features that allowed early humans to run with steady heads held high. “As we started to think more about the nuchal ligament, we became more excited about other features of bones and muscles that might be specialized for running, rather than just walking upright,” Lieberman notes. One that comes immediately to mind is our shoulders. The burly, permanently hunched shoulders of chimps and australopithecines are connected to their skulls by muscles, the better to climb trees and swing from branches. The low, wide shoulders of modern humans are almost disconnected from our skulls, allowing us to run more efficiently but having nothing to do with walking.” Femur fossils of more recent hominins are stronger and larger than older ones, “a difference thought to have evolved to accommodate the added stress of running upright. ^=^
“Then there’s buns. “They are one of our most distinctive features,” Lieberman comments. “They are not just fat but huge muscles.” A quick look at a fossil australopithecine reveals that his pelvis, like that of a chimp, can only support a modest gluteus maximus, the major muscle that comprises a rear end. “These muscles are extensors of the hips,” Lieberman points out, “best used to push apes and australopithecines up the trunks of trees. Modern humans don’t need such a boost, and they don’t use their rear ends for walking. But the instant you start to break into a run, your gluteus maximus starts firing,” Lieberman notes. ^=^
“Such “firing” stabilizes your trunk as you lean forward in a run, that is, as the center of body mass moves in front of your hips. “A run is like a controlled fall,” Lieberman explains, “and your rear end helps you stay up.” Runners also get a lot of help from their Achilles tendons. (Sometimes a lot of trouble, too.) These tough, strong bands of tissue anchor our calf muscles to the heel bone. During a run, they act like springs that contract then uncoil to help push a runner ahead. But they’re not needed for walking. You can stroll across the African plains or city sidewalks without Achilles tendons.” ^=^
Claim That Human Throwing Developed 2 Million Years Ago Greeted with Skepticism
In 2013, scientists said in a study published in Nature that around 2 million years our human ancestors first started throwing with some degree of accuracy and power. Malcolm Ritter of Associated Press wrote: “There's plenty of skepticism about their conclusion. But the new paper contends that this throwing ability probably helped our ancient ancestor Homo erectus hunt, allowing him to toss weapons — probably rocks and sharpened wooden spears. [Source: Malcolm Ritter, Associated Press. June 26, 2013 ***]
“The human throwing ability is unique. Not even a chimp, our closest living relative and a creature noted for strength, can throw nearly as fast as a 12-year-old Little Leaguer, says lead study author Neil Roach of George Washington University. To find out how humans developed this ability, Roach and co-authors analyzed the throwing motions of 20 collegiate baseball players. Sometimes the players wore braces to mimic the anatomy of human ancestors, to see how anatomical changes affected throwing ability. ***
“The human secret to throwing, the researchers propose, is that when the arm is cocked, it stores energy by stretching tendons, ligaments and muscles crossing the shoulder. It's like pulling back on a slingshot. Releasing that "elastic energy" makes the arm whip forward to make the throw. That trick, in turn, was made possible by three anatomical changes in human evolution that affected the waist, shoulders and arms, the researchers concluded. And Homo erectus, which appeared about 2 million years ago, is the first ancient relative to combine those three changes, they said. ***
“But others think the throwing ability must have appeared sometime later in human evolution. Susan Larson, an anatomist at Stony Brook University in New York who didn't participate in the study, said the paper is the first to claim that elastic energy storage occurs in arms, rather than just in legs. The bouncing gait of a kangaroo is due to that phenomenon, she said, and the human Achilles tendon stores energy to help people walk. ***
“The new analysis offers good evidence that the shoulder is storing elastic energy, even though the shoulder doesn't have the long tendons that do that job in legs, she said. So maybe other tissues can do it too, she said. But Larson, an expert on evolution of the human shoulder, said she does not think Homo erectus could throw like a modern human. She said she believes its shoulders were too narrow and that the orientation of the shoulder joint on the body would make overhand throwing "more or less impossible." Rick Potts, director of the human origins program at the Smithsonian Institution, said he is "not at all convinced" by the paper's argument about when and why throwing appeared. ***
“The authors did not present any data to counter Larson's published work that indicates the erectus shoulder was ill-suited for throwing, he said. And it is "a stretch" to say that throwing would give erectus an advantage in hunting, Potts said. Large animals have to be pierced in specific spots for a kill, which would seem to require more accuracy than one could expect erectus to achieve from a distance, he said. Potts noted that the earliest known spears, which date from about 400,000 years ago, were used for thrusting rather than throwing.” ***
Several Homo Species Lived at the Same Time
Broken Hill skull from Zambia Valerie Ross wrote in Discover: “The big-brained, upright primates of the genus Homo—the group to which we modern-day humans belong—evolved in East Africa around 2.4 million years ago. By half a million years later, Homo erectus, from whom we’re directly descended, was walking the plains near Lake Turkana in what is now Kenya. But anthropologists have increasingly come to believe that Homo erectus wasn’t the only hominin around. Three newly discovered fossils, detailed in Nature in August 2012, confirm that at least two other Homo species lived nearby—providing the strongest evidence yet that several evolutionary lineages split off in the genus’s early days. [Source: Valerie Ross, Discover, August 9, 2012 )=(]
“These new discoveries bolster the idea that the human family tree wasn’t, as scientists once thought, a steady climb upward; even within our own genus, life was branching out in several directions. As anthropologist Ian Tattersall told the New York Times, “it supports the view that the early history of Homo involved vigorous experimentation with the biological and behavioral potential of the new genus, instead of a slow process of refinement in a central lineage.”“ )=(
Three Homo Species Living at Same Time: Homo Erectus, Homo Habalis and Homo Rudolfensis?
Seth Borenstein of Associated Press wrote: “The Leakey scientific team contends that other fossils of old hominins - not those cited in their new study - don't seem to match either erectus or 1470. They argue that the other fossils seem to have smaller heads and not just because they are female. For that reason, the Leakeys believe there were three living Homo species between 1.8 million and two million years ago. They would be Homo erectus, the 1470 species, and a third branch. "Anyway you cut it there are three species," study co-author Susan Anton, an anthropologist at New York University. "One of them is named erectus and that ultimately in our opinion is going to lead to us." [Source: Seth Borenstein, Associated Press, August 8 2012]
Both of the species that Meave Leakey said existed back then went extinct more than a million years ago in evolutionary dead-ends. "Human evolution is clearly not the straight line that it once was," Spoor said. The three different species could have been living at the same time at the same place, but probably didn't interact much, he said. Still, he said, East Africa nearly 2 million years ago "was quite a crowded place".
“And making matters somewhat more confusing, the Leakeys and Spoor refused to give names to the two non-erectus species or attach them to some of the other Homo species names that are in scientific literature but still disputed. That's because of confusion about what species belongs where, Anton said. Two likely possibilities are Homo rudolfensis -which is where 1470 and its kin seem to belong - and Homo habilis, where the other non-erectus belong, Anton said. The team said the new fossils mean scientists can reclassify those categorized as non-erectus species and confirm the earlier but disputed Leakey claim.
“But Tim White, a prominent evolutionary biologist at the University of California Berkeley, is not buying this new species idea, nor is Milford Wolpoff, a longtime professor of anthropology at the University of Michigan. They said the Leakeys are making too big a jump from too little evidence. White said it's similar to someone looking at the jaw of a female gymnast in the Olympics, the jaw of a male shot-putter, ignoring the faces in the crowd and deciding the shot-putter and gymnast have to be a different species. Eric Delson, a paleoanthropology professor at Lehman College in New York, said he buys the Leakeys' study, but added: "There's no question that it's not definite." He said it won't convince doubters until fossils of both sexes of both non- erectus species are found. "It's a messy time period," Delson said.
Body Structure of Early Homo Species Very Diverse
Research in the mid 2010s has revealed that not only did early Homo species Homo rudolfensis, Homo habilis and Homo erectus have significant differences in facial features, they also differed throughout other parts of their skeletons and had distinct body forms. According to the University of Missouri-Columbia, a research team found 1.9 million-year-old pelvis and femur fossils of an early human ancestor in Kenya, revealing greater diversity in the human family tree than scientists previously thought. "What these new fossils are telling us is that the early species of our genus, Homo, were more distinctive than we thought. They differed not only in their faces and jaws, but in the rest of their bodies too," said Carol Ward, a professor of pathology and anatomical sciences in the MU School of Medicine. "The old depiction of linear evolution from ape to human with single steps in between is proving to be inaccurate. We are finding that evolution seemed to be experimenting with different human physical traits in different species before ending up with Homo sapiens." [Source: University of Missouri-Columbia, Science Daily, March 9, 2015 /~/]
“Three early species belonging to the genus Homo have been identified prior to modern humans, or Homo sapiens.Homo rudolfensis and Homo habilis were the earliest versions, followed by Homo erectus and then Homo sapiens. Because the oldest erectus fossils that have been found are only 1.8 million years old, and have different bone structure than the new fossil, Ward and her research team conclude that the fossils they have discovered are either rudolfensis or habilis. /~/
Ward says these fossils show a diversity in the physical structures of human ancestors that has not been seen before."This new specimen has a hip joint like all other Homo species, but it also has a thinner pelvis and thighbone compared to Homo erectus," Ward said. "This doesn't necessarily mean that these early human ancestors moved or lived differently, but it does suggest that they were a distinct species that could have been identified not just from looking at their faces and jaws, but by seeing their body shapes as well. Our new fossils, along with the other new specimens reported over the past few weeks, tell us that the evolution of our genus goes back much earlier than we thought, and that many species and types of early humans coexisted for about a million years before our ancestors became the only Homo species left." /~/
“A small piece of the fossil femur was first discovered in 1980 at the Koobi Fora site in Kenya. Project co-investigator Meave Leakey returned to the site with her team in 2009 and uncovered the rest of the same femur and matching pelvis, proving that both fossils belonged to the same individual 1.9 million years ago. /~/
Journal Reference: Carol V. Ward, Craig S. Feibel, Ashley S. Hammond, Louise N. Leakey, Elizabeth A. Moffett, J. Michael Plavcan, Matthew M. Skinner, Fred Spoor, Meave G. Leakey. Associated ilium and femur from Koobi Fora, Kenya, and postcranial diversity in early Homo. Journal of Human Evolution, 2015; DOI: 10.1016/j.jhevol.2015.01.005
Homo Erectus Fossils from Georgia Changes Views of Human Evolution
Fossils found in Dmanisi, Georgia and dated to 1.8 million years ago suggests that half a dozen species of early human ancestor were actually all Homo erectus. Ian Sample wrote in The Guardian: “The spectacular fossilised skull of an ancient human ancestor that died nearly two million years ago has forced scientists to rethink the story of early human evolution. Anthropologists unearthed the skull at a site in Dmanisi, a small town in southern Georgia, where other remains of human ancestors, simple stone tools and long-extinct animals have been dated to 1.8 million years old. Experts believe the skull is one of the most important fossil finds to date, but it has proved as controversial as it is stunning. Analysis of the skull and other remains at Dmanisi suggests that scientists have been too ready to name separate species of human ancestors in Africa. Many of those species may now have to be wiped from the textbooks. [Source: Ian Sample, The Guardian, October 17, 2013]
“The latest fossil is the only intact skull ever found of a human ancestor that lived in the early Pleistocene, when our predecessors first walked out of Africa. The skull adds to a haul of bones recovered from Dmanisi that belong to five individuals, most likely an elderly male, two other adult males, a young female and a juvenile of unknown sex. The site was a busy watering hole that human ancestors shared with giant extinct cheetahs, sabre-toothed cats and other beasts. The remains of the individuals were found in collapsed dens where carnivores had apparently dragged the carcasses to eat. They are thought to have died within a few hundred years of one another. "Nobody has ever seen such a well-preserved skull from this period," said Christoph Zollikofer, a professor at Zurich University's Anthropological Institute, who worked on the remains. "This is the first complete skull of an adult early Homo. They simply did not exist before," he said. Homo is the genus of great apes that emerged around 2.4 million years ago and includes modern humans. |=|
“Other researchers said the fossil was an extraordinary discovery. "The significance is difficult to overstate. It is stunning in its completeness. This is going to be one of the real classics in paleoanthropology," said Tim White, an expert on human evolution at the University of California, Berkeley. But while the skull itself is spectacular, it is the implications of the discovery that have caused scientists in the field to draw breath. Over decades excavating sites in Africa, researchers have named half a dozen different species of early human ancestor, but most, if not all, are now on shaky ground.
“The remains at Dmanisi are thought to be early forms of Homo erectus The Dmanisi fossils show that H erectus migrated as far as Asia soon after arising in Africa. The latest skull discovered in Dmanisi belonged to an adult male and was the largest of the haul. It had a long face and big, chunky teeth. But at just under 550 cubic centimetres, it also had the smallest braincase of all the individuals found at the site. The dimensions were so strange that one scientist at the site joked that they should leave it in the ground. The odd dimensions of the fossil prompted the team to look at normal skull variation, both in modern humans and chimps, to see how they compared. They found that while the Dmanisi skulls looked different to one another, the variations were no greater than those seen among modern people and among chimps.” The fossil is described in an October 2013 issue of Science.” |=|
H Rudolfensis, H Gautengensis, H Ergaster and H Habilis All Homo Erectus?
Ian Sample wrote in The Guardian: “The scientists went on to compare the Dmanisi remains with those of supposedly different species of human ancestor that lived in Africa at the time. They concluded that the variation among them was no greater than that seen at Dmanisi. Rather than being separate species, the human ancestors found in Africa from the same period may simply be normal variants of H erectus. “"Everything that lived at the time of the Dmanisi was probably just Homo erectus," said Prof Zollikofer. "We are not saying that palaeoanthropologists did things wrong in Africa, but they didn't have the reference we have. Part of the community will like it, but for another part it will be shocking news." [Source: Ian Sample, The Guardian, October 17, 2013]
“David Lordkipanidze at the Georgian National Museum, who leads the Dmanisi excavations, said: "If you found the Dmanisi skulls at isolated sites in Africa, some people would give them different species names. But one population can have all this variation. We are using five or six names, but they could all be from one lineage." If the scientists are right, it would trim the base of the human evolutionary tree and spell the end for names such as H rudolfensis, H gautengensis, H ergaster and possibly H habilis. "Some palaeontologists see minor differences in fossils and give them labels, and that has resulted in the family tree accumulating a lot of branches," said White. "The Dmanisi fossils give us a new yardstick, and when you apply that yardstick to the African fossils, a lot of that extra wood in the tree is dead wood. It's arm-waving." |=|
“"I think they will be proved right that some of those early African fossils can reasonably join a variable Homo erectus species," said Chris Stringer, head of human origins at the Natural History Museum in London. "But Africa is a huge continent with a deep record of the earliest stages of human evolution, and there certainly seems to have been species-level diversity there prior to two million years ago. So I still doubt that all of the 'early Homo' fossils can reasonably be lumped into an evolving Homo erectus lineage. We need similarly complete African fossils from two to 2.5 million years ago to test that idea properly." |=|
“The analysis by Lordkipanidze also casts doubt on claims that a creature called Australopithecus sediba that lived in what is now South Africa around 1.9 million years ago was a direct ancestor of modern humans. The species was discovered by Lee Berger at the University of Witwatersrand. He argued that it was premature to dismiss his finding and criticised the authors for failing to compare their fossils with the remains of A sediba. "This is a fantastic and important discovery, but I don't think the evidence they have lives up to this broad claim they are making. They say this falsifies that Australopithecus sediba is the ancestor of Homo. The very simple response is, no it doesn't. What all this screams out for is more and better specimens. We need skeletons, more complete material, so we can look at them from head to toe," he added. "Any time a scientist says 'we've got this figured out' they are probably wrong. It's not the end of the story." |=|
Last Homo Erectus
Skull from Sangiran In addition to that “Homo erectus” fossils found at site called Ngandong in Indonesia, previously thought to be between 100,000 and 300,000 years old, were dated in strata between 27,000 and 57,000 years old. This implies that “Homo erectus” live much longer than anyone thought and “Homo erectus” and “Homo sapiens” existed at the same time on Java. Many scientists are skeptical about the Ngandong dates.
Image Sources: All Posters com 2) Peking Man skull, Wesleyan University ; 3) Peking Man cave, World Heritage Site website; 4) Peking Man bust, World Heritage Site website ; Others Wikimedia Commons
Text Sources: National Geographic, New York Times, Washington Post, Los Angeles Times, Smithsonian magazine, Nature, Scientific American. Live Science, Discover magazine, Discovery News, Natural History magazine, Archaeology magazine, The New Yorker, Time, Newsweek, BBC, The Guardian, Reuters, AP, AFP and various books and other publications.
Last updated September 2018