Latest news with #Australopithecusafarensis
Forbes
27-04-2025
- Science
- Forbes
How Earth's Mantle Played A Role In Shaping Human Evolution
A sculptor's rendering of the hominid Australopithecus afarensis that lived 3.2 million years ago in ... More Africa. An international team of researchers investigated how Earth's mantle activity created an uplift between what is now the Arabian Peninsula and Anatolia about 35 to 20 million years ago. The resulting land bridge enabled the early ancestors of animals such as giraffes, elephants, rhinoceroses, cheetahs, and even humans, to leave Africa, ending a 75-million-year-long isolation of the continent. "This study has relevance to the question of 'How did our planet change, in general? What are the connections between life and tectonics?'" says Thorsten Becker, a study co-author and professor at the Jackson School's Department of Earth and Planetary Sciences and Institute for Geophysics, University of Texas. The full story begins 70 to 60 million years ago, when a slab of rock sliding into Earth's mantle melted, creating a plume that reached the surface some 30 million years later. The mantle plume pushing upwards, coupled with the collision of tectonic plates between Africa and Asia, created an uplift that contributed to closing the ancient Tethys Sea, splitting it into what is now the Mediterranean and Arabian Seas, and created a landmass that bridged Asia and Africa for the first time. In a similar way Iceland is today above sea level because it sits atop a mantle plume and between two tectonic plates. The study's lead author Eivind Straume analyzed the wide-ranging consequences of this geologic activity while he was a postdoctoral fellow at the Jackson School. He says the appearance of the land bridge and evolution of early hominids go hand in hand. "The shallow seaway closed several million years before it otherwise likely would have due to these specific processes—mantle convection and corresponding changes in dynamic topography," explains Straume, who is now a postdoctoral fellow at the Norwegian Research Center and The Bjerknes Center for Climate Research. "Without the plume, you could argue that the continental collision would have been different." Without the mantle plume, Africa and Asia may have remained isolated for much longer, and the animals that made their way into and out of Africa, including our ancestors, could have been much different. Several million years before the land bridge had completely closed, the primate ancestors of humans came to Africa from Asia. While those primates ended up going extinct in Asia, their lineages diversified in Africa. Then when the land bridge fully emerged, these primates re-colonized Asia and Europe. This uplift also had significant impacts on ocean circulation and Earth's climate. Without the Tethys Sea and oceanic currents redistributing energy to the north, the Indian Ocean got warmer and eastern Africa became more arid. Researchers believe this event was a final trigger in making the Sahara a desert, maybe even driving early hominids out of Africa as they followed the rain some 10 to 7 million years ago. The warmer ocean also enhanced evaporation and monsoon activity making southeast Asia wetter. This paper brings together existing research spanning plate tectonics, mantle convection, topography and paleogeography, evolutionary anthropology, mammal evolution, climate evolution, and ocean circulation, among other topics, to tell a cohesive story of the wide-ranging effects of these mantle dynamics. The study, "Collision, mantle convection and Tethyan closure in the Eastern Mediterranean," was published in the journal Nature Reviews Earth & Environment. Additional material and interviews provided by University of Texas at Austin.
Yahoo
09-04-2025
- Science
- Yahoo
The ‘true face' of Lucy, humanity's most famous ancestor
The true face of the tiny primate 'Lucy', who proved that our early human relatives walked on two legs 3 million years ago, has been revealed. The 3.5ft skeleton, named after the Beatles song Lucy in the Sky with Diamonds, was discovered in Ethiopia by Donald Johanson, an American palaeoanthropologist, in 1975. She belonged to the Australopithecus afarensis species and was the most intact early hominin ever found, which helped prove that our human ancestors walked on two legs before developing large brains. Before her discovery, many people had hypothesised that a larger brain was needed to allow the dexterity needed for upright walking. Now, an international team including Cicero Moraes, a world leader in forensic facial reconstruction software, has reconstructed her face using scans of her skull, coupled with soft tissue data from chimpanzees, who have a similar brain size to the Australopithecus afarensis. 'Seeing Lucy's face is like glimpsing a bridge to the distant past, offering a visual connection to human evolution,' said Mr Moraes. 'The reconstruction, blending science and art, allows us to imagine what she might have looked like 3.2 million years ago, enriching both public and scientific understanding of our ancestors. 'It's a reflection of technological progress that makes an extinct being tangible.' Details like hair and skin colour were determined based on prior studies related to the Pliocene environment in which she lived. The final result is something not quite ape and not yet human, similar to modern great apes but with some unique features, such as a flatter face and a less protruding jaw. 'It has a less pronounced brow ridge than in chimpanzees, though still distinct from modern humans,' added Mr Moraes. 'The artistic version shows dark skin and hair, inspired by palaeoanthropological descriptions suggesting adaptation to the hot Ethiopian environment of 3.2 million years ago.' He added: 'The team believes that, despite the limitations of the cranial fragments, it offers an anatomically coherent representation of a female Australopithecus afarensis.' Lucy's body also shows elements of both ape and human. Her upper torso shows she was adapted to living in trees, but her lower body shows she also walked on two legs. Her brain, however, is very different to modern humans. The inner surface of her skull has a volume of about 391 cubic centimetres – similar to that of chimpanzees and much smaller than the roughly 1,350 cubic centimetres of modern humans. It indicates that her brain organisation was closer to that of other primates. Lucy is thought to have died between 12 and 18 years of age – adulthood for her species – and may have fallen out of a tree. Her fossilised bones will go on display in Europe for the first time this summer at Prague's National Museum in August. The research has been submitted to a journal for peer review. Broaden your horizons with award-winning British journalism. Try The Telegraph free for 1 month with unlimited access to our award-winning website, exclusive app, money-saving offers and more.
Telegraph
09-04-2025
- Science
- Telegraph
The ‘true face' of Lucy, humanity's most famous ancestor
The true face of the tiny primate 'Lucy', who proved that our early human relatives walked on two legs 3 million years ago, has been revealed. The 3.5ft skeleton, named after the Beatles song Lucy in the Sky with Diamonds, was discovered in Ethiopia by Donald Johanson, an American palaeoanthropologist, in 1975. She belonged to the Australopithecus afarensis species and was the most intact early hominin ever found, which helped prove that our human ancestors walked on two legs before developing large brains. Before her discovery, many people had hypothesised that a larger brain was needed to allow the dexterity needed for upright walking. Now, an international team including Cicero Moraes, a world leader in forensic facial reconstruction software, has reconstructed her face using scans of her skull, coupled with soft tissue data from chimpanzees, who have a similar brain size to the Australopithecus afarensis. 'Seeing Lucy's face is like glimpsing at a bridge to the distant past, offering a visual connection to human evolution,' said Mr Moraes. 'The reconstruction, blending science and art, allows us to imagine what she might have looked like 3.2 million years ago, enriching both public and scientific understanding of our ancestors. 'It's a reflection of technological progress that makes an extinct being tangible.' Details like hair and skin colour were determined based on prior studies related to the Pliocene environment in which she lived. The final result is something not quite ape and not yet human, similar to modern great apes but with some unique features, such as a flatter face and a less protruding jaw. 'It has a less pronounced brow ridge than in chimpanzees, though still distinct from modern humans,' added Mr Moraes. 'The artistic version shows dark skin and hair, inspired by palaeoanthropological descriptions suggesting adaptation to the hot Ethiopian environment of 3.2 million years ago.' He added: 'The team believes that, despite the limitations of the cranial fragments, it offers an anatomically coherent representation of a female Australopithecus afarensis.' Lucy's body also shows elements of both ape and human. Her upper torso shows she was adapted to living in trees, but her lower body showed she also walked on two legs. Her brain, however, is very different to modern humans. The inner surface of her skull has a volume of about 391 cubic centimetres – similar to that of chimpanzees and much smaller than the roughly 1,350 cubic centimetres of modern humans. It indicates that her brain organisation was closer to that of other primates. Lucy is thought to have died at between 12 and 18 years of age – adulthood for her species – and may have fallen out of a tree. Her fossilised bones will go on display in Europe for the first time ever this summer at Prague's National Museum in August. The research has been submitted to a journal for peer review.
Yahoo
12-03-2025
- Science
- Yahoo
We modelled how early human ancestors ran – and found they were surprisingly slow
Imagine the scene, around 3 million years ago in what is now east Africa. By the side of a river, an injured antelope keels over and draws its last breath. The carcass is soon set on by hyenas, who tussle with a crocodile. The crocodile surfaces and grabs part of the animal. The hyenas win and the crocodile retreats with only a leg. After having their fill, the hyenas slope off. Some funny-looking apes approach, walking upright. They have what appear to be stones with sharp edges in their hands. They hurriedly cut off some scraps of meat and start chewing at them. Their squabbling attracts the attention of a nearby Homotherium (an extinct, scimitar-toothed big cat) who creeps up and suddenly breaks cover. Will these strange apes survive the encounter? Can they run fast enough, and far enough? Our team's research modelled the anatomy of these early humans, Australopithecus afarensis, to find out how well they could run. Australopithecus afarensis is one of the best-known early human ancestors dating from 2.9-3.9 million years ago. The partially complete Australopithecus afarensis skeleton Lucy, or Dinkʼinesh (Amharic: ድንቅ ነሽ, lit.'you are marvellous') is globally iconic as a representation of early bipedalism (the ability to walk on two legs). Found in the Afar Depression in north east Ethiopia, this discovery received worldwide attention when it was made in 1974. It was evidence that brain expansion evolved after human ancestors started walking on two legs, as scientists had long believed. Some researchers have also linked Australopithecine anatomy to an, as yet unknown, knuckle-walking common ancestor of humans, gorillas and chimpanzees. This hypothesis has since been refuted. Scientists now believe that knuckle-walking probably evolved several times in apes, as the style of walking and internal architecture of ape hands and elbows are subtly different from each other. Researchers also think that the anatomy we see in hominins reflects an adaptation for upright movement in trees in a distant ancestor. Early bipeds, such as Ardipithecus kadabba which looked a bit like a gorilla, lived in Africa between 5.8 and 5.2 million years ago. They lived in mosaic habits (a mixture of open and wooded landscapes) so some adaptation to moving in trees would make sense. Until recently, scientists thought that only animals of the genus Homo, which emerged around 2 million years ago, made stone tools. The discovery of cut-marked bones in Dikika, Ethiopia (in 2009) dated at 3.4 million years, and in 2011 of stone tools at Lomekwi, Kenya from 3.3 million years ago, changed scientists' ideas of how much access Australopithecus had to meat. The debate is now more a matter of whether Australopithecus regularly killed animals themselves, or if they were eating from carcasses after other predators (secondary access). For primary access and regular kills, they needed to be able to do two things. Run fast (bursts of speed to outpace an unaware animal), and run for long amounts of time (to wear down a prey animal). This is the endurance running hypothesis. The emergence of this behaviour is thought to coincide with more modern anatomy, such as seen in Homo erectus, who lived from around 2 million years ago to around 1 million years ago. The best way to test if Australopithecus was capable of endurance running at what we consider 'modern' speeds is to reconstruct the skeleton of Australopithecus afarensis and simulate how they may have moved. To try and answer this question, my team reconstructed the complete skeleton of Lucy, using 3D modelling. Where parts were missing, we estimated these using scaled versions of other Australopithecus skeletons. Since Lucy is a shared ancestor for chimpanzees as well, we also morphed Australopith and modern human and chimpanzee skeletal material, using an analytical technique called geometric morphometrics. We then started putting muscles onto the bones of the pelvis and lower limbs of Australopithecus and a modern human model, using the open source software Gaitsym. Muscles and other soft tissues are not preserved in fossils so we varied the muscle properties from chimpanzee-like to human-like, producing a range of estimates for running speed and economy. We also ran multiple simulations where we added and removed a long Achilles tendon, which chimpanzees don't have, as it is thought to affect running speed and energy use by enhancing recovery. This was a team effort, with reconstructions across multiple labs. The simulations were run on the high performance computing facilities at the University of Liverpool. These simulations revealed that Lucy wasn't as good at running as modern humans. The top speed our simulations could produce was 11mph, with a minimum of about 3.35mph. Elite sprinters, however, can reach peak speeds of more than 20mph. Even non-elite sprinters can reach around 17.6mph. We also found that the metabolic cost of transport (how much energy it takes to move) was between 1.7 and 2.9 times higher in Lucy than in a modern human. The more 'ape like' you make the muscle architecture and the shorter you make the Achilles tendon, the higher this cost is. It appears that modern human limb proportions, combined with key changes in architecture of the calf muscle (such as relatively short fibres and large cross sectional areas), plus a long Achilles tendon, enabled much faster running in the genus Homo. This means that it was probably not physiologically possible for Australopithecus afarensis to engage in persistence hunting, unlike later species of the genus Homo species. Going back to our story at the start, it is likely the Australopithecines in this group wouldn't have escaped the big cat. They simply couldn't run fast enough, or for long enough. This article is republished from The Conversation under a Creative Commons license. Read the original article. Tom O'Mahoney does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
Observer
08-02-2025
- Science
- Observer
Prague museum to host first European display of 3.18 million year old Lucy
The bone fragments of Lucy, a 3.18 million year-old human ancestor which rarely leave Ethiopia, will go on display in Europe for the first time in Prague this year, the Czech premier said Tuesday. The ancient remains of the Australopithecus afarensis were discovered in Ethiopia in 1974. The find was, at the time, the most complete ever found, and revolutionised the understanding of humanity's ancestors. "Lucy's skeletal remains will be displayed in Europe for the first time ever," Prime Minister Petr Fiala told reporters as he announced the rare loan by Ethiopia's National Museum. The fragments will be shown at Prague's National Museum as part of a "Human Origins and Fossils" exhibition for two months from August 25. The remains will be presented alongside Selam, the fossil of a baby Australopithecus who was about 100,000 years older than Lucy and found in the same place 25 years later. "This historic exhibition... will offer tourists and researchers a once-in-a-lifetime opportunity to see these priceless fossils first-hand," said Ethiopian Tourism Minister Selamawit Kassa. A man looks at the hyperrealistic artistic reconstruction of the human ancestors in the National Museum of Prague on February 4, 2025 in Prague, on the sidelines of a press conference held by the Czech Prime Minister and Ethiopia's Tourism Minister (both unseen) about bone fragments of Lucy, a 3.18 million year-old human ancester which rarely leave Ethiopia, will go on display from August 25 in Prague, for the first time ever in Europe. The ancient remains of the Australopithecus afarensis were discovered in Ethiopia in 1974. The find was, at the time, the most complete ever found, and revolutionised the understanding of humanity's ancestors. "Lucy's skeletal remains will be displayed in Europe for the first time ever," Prime Minister Petr Fiala told reporters as he announced the rare loan by Ethiopia's National Museum. The fragments will be shown at Prague's National Museum as part of a "Human Origins and Fossils" exhibition for two months from August 25. In her current shape, Lucy consists of fossilised dental remains, skull fragments, parts of the pelvis and femur. The fossilised skeleton of the 1.1-metre-tall (3.6 feet), 29-kilogramme (64-pound) Lucy last left Ethiopia between 2007 and 2013 when it toured US museums. The hominid was named after the Beatles' song "Lucy in the Sky with Diamonds" which the team that had found her listened to after the discovery. Lucy walked on two legs and is thought to have died aged between 11 and 13 -- considered an adult for this species. She was believed to be the oldest human ancestor found until the discovery of "Toumai" in Chad in 2001 -- a skull dated to six or seven million years old. In a 2016 study, researchers said Lucy had strong upper arms, suggesting she regularly climbed trees and nested in branches at night. She also had relatively weak legs that were not used for climbing and were inefficient for walking, the study concluded. An analysis of a fracture on one of Lucy's bones in the same year suggested that she probably died from a fall from a tall tree. Long considered the longest living human relative, Lucy was dethroned of her status in 1994 following the discovery -- also in Ethiopia -- of Ardi, a female Ardipithecus ramidus who lived 4.5 million years ago. —AFP
