生成一个科普视频---**Subject:** HISTORY **Question:** WHO WAS THE FIRST HUMAN? **Header** DID YOU KNOW? Lucy's Ethiopian name is Dink'inesh, which translates to 'you are marvellous' **Main Title/Introduction** 50 years ago, Lucy, the famous fossil and most complete skeleton of the species Australopithecus afarensis, was discovered, filling in gaps in human history WORDS AILSA HARVEY **Main Article Text** A bout 3.2 million years ago, an early human of the hominid species Australopithecus afarensis lived in the forests of Ethiopia. She walked in a similar fashion to a chimp, with her hips and knees bent, but she covered land on two feet. Half of her time was spent in the trees, as this early human had long, strong arms and branch-grasping hands. Scientists estimate that this human ancestor died when she was between 12 and 18 years old, her body left in the sediment of an ancient lake. Little did she know that she would come back to life in the imagination of modern-day Homo sapiens millions of years later. After her body was concealed by layers of sediment, her bones became fossilised and lay in the earth undisturbed until 1974, when the sediment had eroded enough for her fossilised elbow to poke out the ground. Upon retrieving the remains, the ancient human was named 'Lucy'. Since the discovery of Lucy, scientists have been able to update our evolutionary timeline, placing walking humans further back in our history. Her species is thought to have foraged for fruits, nuts and seeds in both woodlands and the savannah. By studying Lucy's bones, scientists have found close links between her species and orangutans. Her **Quote Box** “Since the discovery of Lucy, scientists have been able to update our evolutionary timeline” **Main Article Text (continued)** proportions showed that Australopithecus afarensis probably spent most of their time upright, but also moved with the assistance of their arms in some environments – such as scaling trees in forests. Lucy has become famous as the first significant insight into hominid life 3.2 million years ago. Using casts of her fossil, clay models with muscles, skin and hair have been created, showing how Lucy would have looked during her lifetime. The detailed features of her bone composition give scientists an estimate of what her height and weight were, and have enabled people to imagine Lucy interacting with Earth's landscapes. Although scientists can't tell exactly how much hair Lucy had, it is thought to be somewhere between that of a chimpanzee and that of a human. Since Lucy, there have been more than 300 other Australopithecus afarensis remains found. But these fossilised specimens are just a sample of those that made up a core species in human evolution – the earliest of our ancestors and one that navigated the planet for more than a million years. **Did You Know Box** Did you know? Lucy weighed 27 to 29 kilograms **Footer/Credit** © Alamy HISTORY **BIPEDAL BEINGS** From studying Lucy's extensive skeleton, anthropologists discovered that humans were standing on two feet and walking long before the first complex stone tools were made. This suggests that walking, or bipedalism, came before humans developed larger brains and that walking was one of the earliest stages to becoming human. Her remains have given scientists a clearer and more accurate picture of the human evolutionary timeline. But why is becoming bipedal so revolutionary? Over long distances, walking on two legs is much more energy efficient than using four. This would have benefited our ancestors in places like East Africa and the savannah, where food was scarce and extensive roaming was required. It also freed up the hands for carrying sourced food and later creating tools. As a walker, Lucy would have increased her awareness of her surroundings by standing upright with a better view of what's around her. Finally, being more vertical than horizontal reduces the amount of surface area for direct sunlight to hit the body, keeping early humans cooler and reducing ultraviolet exposure at latitudes with strong sunshine. This model shows Lucy's bones, aligned to demonstrate her upright posture **SKELETAL FINDINGS** What does each fossilised body part tell scientists about Lucy's species? **1 BIG BRAIN** Skull fragments suggest Lucy's brain had a volume of 375 to 500 cubic centimetres, like a modern-day chimpanzee's. **2 VARIED DIET** Lucy's teeth include large molars for eating tough, fibrous plants and possibly meat. **3 CURVED SPINE** The shapes of the vertebrae show similar curvature to the spines of modern humans, suggesting she walked on two feet. **4 BALANCING ACT** The pelvis bone is broad and shaped like a basin, helping to balance her body weight while walking. **5 CHILD-BEARING** Lucy's sacrum is one telling sign that she was female. It's wide to allow space for childbirth. **6 FEMUR FACTS** The thigh bone slants inwards to direct the body's centre of mass over the feet when walking. **7 LONG ARMS** Lucy had long upper arms compared to her legs to assist her in climbing trees. **8 GOOD CLIMBER** Curved finger bones suggest Lucy was adept at grasping branches. **9 APE RELATIVES** The shape of the rib cage is similar to that of great apes. "Lucy has become famous as the first significant insight into hominid life" --- **Chart/Diagram Description:** Type: Composite illustration featuring text blocks, fossil photographs, and a skeletal model photograph. Main Elements: * **Text Blocks:** Includes main headers ("HISTORY", "BIPEDAL BEINGS", "SKELETAL FINDINGS"), detailed paragraphs, numbered fact boxes with titles and descriptions, and a quote. * **Fossil Photographs:** Scattered photographs of various fossilized bone fragments are arranged around the "SKELETAL FINDINGS" section. Purple numbered squares (1-9) are placed near specific bone fragments or groups of fragments, corresponding to the numbered facts. * 1: Points to skull fragments. * 2: Points to jaw and teeth fragments. * 3: Points to vertebrae fragments and rib fragments. * 4: Points to pelvis fragments. * 5: Points to a sacrum fragment (part of the pelvis). * 6: Points to a femur (thigh bone). * 7: Points to arm bone fragments (humerus, ulna/radius). * 8: Points to finger bone fragments. * 9: Points to rib fragments. * **Skeletal Model Photograph:** A photograph on the lower left shows a full skeletal reconstruction of Lucy in an upright posture. A caption is below this image. * **Lines and Shapes:** Lines connect the numbers on the fossil photos to the corresponding fact boxes. Geometric shapes like the purple squares with numbers are used as markers. * **Relative Position:** The main text about bipedalism is on the left. The fossil fragments, numbered facts, and "SKELETAL FINDINGS" title are on the right. The skeletal model photo is below the bipedalism text. The quote is at the bottom right. DID YOU KNOW? Lucy's bones are kept in the National Museum of Ethiopia **ANCESTOR EVOLUTION** How Australopithecus afarensis became Homo sapiens **AUSTRALOPITHECUS AFARENSIS** 3.9 TO 2.9 MILLION YEARS AGO Lucy's species had a brain a third the size of a modern human's. They had a low, sloping forehead as they had a smaller frontal lobe. Large brow ridges gave structural support to the skeleton from powerful chewing muscles that worked on tough foods. **HOMO HABILIS** 2.4 MILLION YEARS AGO Homo habilis had a brain size around 100 cubic centimetres larger than the upper estimate of A. afarensis' 500 cubic centimetre brain. The species used stone tools and problem-solving abilities to manipulate the environment. **HOMO ERECTUS** 1.8 MILLION YEARS AGO Homo erectus left Africa nearly 2 million years ago for Asia and Europe. The species had much longer legs to travel long distances. Did you know? 47 of Lucy's 207 bones were found **HOMO NEANDERTHALENSIS** 400,000 TO 40,000 YEARS AGO Their brains were larger than those of modern humans at 1,750 cubic centimetres, and they demonstrated complex behaviours like sophisticated tool use, burying the dead and complex communication. **HOMO SAPIENS** 300,000 YEARS AGO TO TODAY Homo sapiens have a more rounded skull, smaller brow ridges and jaw and a slightly smaller brain than Homo neanderthalensis as we don't require as much scent and visual processing to survive. We instead have advanced cognitive abilities and are capable of abstract thought. **LUCY'S DEMISE** Research that took place in 2016 – 42 years after Lucy's remains were uncovered – has been used in an effort to determine the circumstances around how Lucy died. Anthropologists at the University of Texas at Austin suggest that her skeleton's condition and location mean she is likely to have fallen to her death from a great height. To come to this conclusion, the researchers analysed the skeleton and made educated assumptions about her way of life. Being of small stature at one metre in height, Lucy likely climbed trees to stay away from threats like sabre-toothed cats. This could include resting at heights of an average of around 14 metres, as chimps usually do. The theory is that Lucy fell from a tree at around this height, plummeting to the ground feet first at 35 miles per hour. She suffered fractures to her ankles, knees, hip and shoulder and punctured her internal organs in the process. To try and break the fall, Lucy would have put her arms forwards, which is what caused the fractures in her arm bones. This breakage then caused her to twist to the right and fracture her neck. Some scientists believe Lucy fell from a tree. Others think the bone damage is due to time under the heavy sediment. **Chart/Diagram Description:** * **Type:** Evolutionary timeline illustrated with figures representing different hominid species. * **Main Elements:** * Five illustrated human-like figures are depicted standing and walking, arranged left to right. * Each figure represents a different species in human evolution. * Below each figure is a labeled text box containing the species name and the approximate time period they lived, along with a brief description of their characteristics. * The figures generally progress from shorter and more ape-like on the left (Australopithecus afarensis) to taller and more modern human-like on the right (Homo sapiens). * The overall arrangement suggests a chronological progression or evolution from left to right. * The title "ANCESTOR EVOLUTION" and subtitle "How Australopithecus afarensis became Homo sapiens" are at the top. * A separate text box titled "Did you know?" is positioned between the Homo erectus and Homo neanderthalensis descriptions. * The bottom section titled "LUCY'S DEMISE" includes text describing research about Lucy's death and an image of a fossilized skull and bone fragments (presumably Lucy's remains). A caption is below this image. **Infographic Title:** HISTORY **Infographic Subtitle:** FINDING LUCY **Infographic Description:** How we have learned from Lucy in the 50 years since her remains were uncovered **Main Sections & Timeline of Discovery:** **Section 1:** EXPEDITION PREPARATION **Period:** 1973 TO 1974 **Text:** The International Afar Research Expedition was led by palaeoanthropologists Donald Johanson and Maurice Taieb in the Hadar region of Ethiopia. The aim was to search for early hominin fossils. **Image:** World map showing the location of Hadar region in Ethiopia. **Section 2:** EXCAVATION **Period:** NOVEMBER 1974 **Text:** Over the next few weeks, the team carefully excavated the remaining fossils. They found 40 per cent of a hominin skeleton – these discoveries usually included a few bones. **Image:** Photo of fossil fragments, including a pelvis and jawbone. **Section 3:** DISCOVERY ANNOUNCEMENT **Period:** 1975 **Text:** The findings were published and announced in the scientific community. It was a significant find as the most complete collection of skeletal fossils from an early hominid. It also challenged the known timeline of human evolution. **Section 4:** ONGOING FINDINGS **Period:** 1970S TO 1980S **Text:** After the successful excavation of Lucy, palaeoanthropologists began to focus their excavations on the surrounding area to see what else could lie beneath the soil. Over 300 more individuals of the same species were uncovered. **Section 5:** CONTINUED RESEARCH **Period:** 2000S TO PRESENT **Text:** Scientists are able to look into Lucy’s bones with increasing detail. For example, computed tomography (CT) allows external and internal scans without causing damage to the fossils. **Annotation:** Today, digital replicas of Australopithecus afarensis can be created and experimented with freely without damaging the fossil. **Image:** Digital replica of an Australopithecus afarensis skeleton. **Timeline at bottom:** Years marked: 1970, 1980, 1990, 2000, 2010, 2030 **Events on Timeline:** **Event 1:** FIRST FINDING **Date:** 24 NOVEMBER 1974 **Text:** After taking an alternative route back to their vehicle, Johanson spotted a forearm bone. The team recognised it to be of a hominid, and upon further inspection saw this bone was surrounded by additional fragments. **Image:** Photo of Donald Johanson. (Source: ©Wikimedia Commons) **Event 2:** NAMING LUCY **Date:** 24 NOVEMBER 1974 **Text:** While celebrating the find in the evening, the Beatles song Lucy in the Sky With Diamonds started playing. It was suggested that the skeleton be referred to as Lucy, and this name caught on. **Event 3:** INITIAL ANALYSIS **Period:** 1975 **Text:** After early analysis of the fossils, scientists found that Lucy was a small adult female, 107 centimetres in height. After looking at her knee joint, the team concluded that her species was bipedal. **Event 4:** NAMING THE SPECIES **Period:** 1978 **Text:** Four years after her discovery, Lucy's species was given a name. This followed detailed studies and comparisons between known species to provide an accurate name. Australopithecus afarensis incorporates details of its ape (Australopithecus) characteristics and location of the discovery in Afar, Ethiopia. **Event 5:** NEW THEORIES **Period:** 1980S TO 1990S **Text:** Initially, it was thought that Lucy led a ground-dwelling lifestyle, but studies into her climbing adaptations opened new theories about time spent in the branches. **Image Comparison:** **Description:** Three skeletal reconstructions shown side-by-side. **Labels:** * Left: Lucy's height * Middle: Homo ergaster * Right: Homo neanderthalensis **Annotation:** Lucy's height (left) compared to Homo ergaster (middle) and Homo neanderthalensis (right) **Image Reconstruction:** **Description:** Artistic reconstruction of an Australopithecus afarensis individual (Lucy) holding stone tools. **Annotation:** Evidence suggests Lucy's species used simple stone tools. **Extraction Content:** **Title/Heading:** DID YOU KNOW? Fossilised turtle and crocodile eggs were found near the site of Lucy's grave **Did You Know? Box:** Did you know? Lucy was as tall as a modern five year old **Geological Illustration Section:** Title: EXCAVATION IN ETHIOPIA Subtitle: How did Lucy's environment conceal and preserve her? Explanations corresponding to numbered areas in the illustration: 1 DESERT SOIL Low moisture in the desert helped prevent rapid decomposition, allowing the remains to eventually fossilise. 2 ERODED SANDSTONE Sandstone covered Lucy's remains as layers of sand compacted over time. The sandstone formed a protective layer around the bones and gaps within them. 3 VOLCANIC DEPOSIT Volcanic ash layers helped to date the fossils. This layer was 3.2 million years old, which was calculated by comparing the ratio of potassium to argon. 4 EXPOSED BONES Erosion by wind and water wore away the rock layers to reveal Lucy's whereabouts. 5 UNDISTURBED AREA More bones were covered by the rock below. Their static positioning in the rock helped the team piece together Lucy's structure. 6 VOLCANIC DEPOSIT This layer of volcanic rock was 3.8 million years old. As Lucy was sandwiched between the layers, her time on Earth could be estimated. 7 ANCIENT LAKEBED The fine-grained sediment of a lakebed in Hadar quickly covered Lucy's bones to preserve them. 8 BEDROCK The stable bedrock kept the layers of sediment from shifting over millions of years. **Making Faces Section:** Title: MAKING FACES Text: Reconstructing a digital image of Lucy's face is a difficult task, because only a few cranial bones were preserved. However, her lower jawbone is almost complete, which provided a starting point for reconstructing the head. Using CT scans of Lucy's fossilised bones alongside data derived from other early hominin facial characteristics, an estimate of what the individual may have looked like was pieced together. Today, advanced technologies like 3D imaging are able to produce detailed digital models. Any extra data collected about the specimen can be included in the algorithm to make models more accurate. For example, data about skin thickness and the positions of facial muscles can be altered. To further examine how her bones would have moved with each other, the fossils have been recreated as 3D-printed replicas. This means that scientists can experiment with movements and attach models of missing bone pieces without damaging the fossils. Quote: “3D imaging is able to produce detailed digital models” Caption under face image: By manipulating the muscles and skeleton, scientists can experiment with Lucy's facial expressions **Attribution:** © Alamy / Shutterstock / Illustration by Adrian Mann **Chart/Diagram Description:** **Image 1: Geological Cross-section Diagram** * Type: Cross-section diagram illustrating geological layers. * Main Elements: * Layers: Depicts multiple distinct horizontal layers of rock and soil in different colors (brown, light yellow/tan, reddish-brown bands, grey/beige, dark brown). * Numbers: Large purple numbers (1 through 8) are placed on or near the layers to label specific areas or deposits. * Dashed Lines: Purple dashed lines with small arrows connect some numbers (3, 5, 6, 7) to specific layers within the diagram, indicating the location corresponding to the numbered explanation. * Structure: The layers are shown in a vertical sequence, suggesting deposition over time, with older layers towards the bottom (Bedrock, 8) and younger layers towards the top (Desert Soil, 1). The layers appear slightly tilted or eroded in parts. **Image 2: Facial Reconstruction Photograph** * Type: Photograph of a detailed facial reconstruction. * Main Elements: * Subject: Close-up view of the face of a hominin reconstruction (presumably Lucy). * Features: Shows details of skin texture (wrinkles), eyes (brown iris, sclera), nose (broad), mouth (slightly open, showing teeth), and hair (sparse). * Perspective: Frontal view, slightly angled, focusing on the face from roughly the eyes downwards.