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http://www.newsweek.com/humans-arrived-australia-thousands-years-thought-638914

 Tech & Science
First Humans in Australia Arrived Thousands of Years Earlier Than We Thought
By Hannah Osborne On 7/19/17 at 1:00 PM


Tech & Science
Evolution
paleoanthropology
Archaeology

The first humans arrived in Australia up to 15,000 years earlier than previously thought, scientists have announced.

During excavations of the Madjedbebe rock shelter in northern Australia, researchers have found thousands of artefacts, including stone tools, grinding stones and hatchets, showing humans must have been at the site at least 65,000 years ago.

The findings, published in Nature, have major implications for our understanding of early human migration beyond Asia, why Australia’s megafauna went extinct, and, potentially, if these early humans interacted with Homo floresiensis, the mystery “hobbit-like” species found only on the Indonesian island of Flores.

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Madjedbebe is one of the key sites when it comes to the debate of when humans first arrived in Australia. It was first discovered in the 1970s and excavations have taken place at the site ever since. Initial reports indicated human presence in Australia from between 50,000 and 60,000 years ago, but these findings were highly contentious due to questions over the dating techniques used.

At present, estimates for mankind’s arrival in Australia range from between 47,000 and 60,000 years.

Chris Clarkson Excavation leader Chris Clarkson examines a stone tool. Gundjeihmi Aboriginal Corporation 2015.

Now, however, researchers have excavated thousands more artefacts from Madjedbebe, providing new and robust evidence for when the site was occupied by humans. During the dig, archaeologists found around 11,000 artefacts and matched them to the age of the sediments in which they were found. By doing this, they were able to accurately date them—showing the oldest artefacts were around 65,000 years old.

Lead author Chris Clarkson tells Newsweek: “I have no concerns the dates are incorrect. We have dated thousands of sand grains from dozens of samples across the site and the results show very accurate ages with little mixing.”

He says the artefacts are in good positions, with broken ones not falling between different layers of sediment. “Furthermore, at the front of the shelter there is a dense concentration of rockfall which traps the artefacts in place,” he continues. “These show nice lenses of artefacts that are indicative of numerous episodes of occupation and cannot have moved since the site formed.”

It is thought the first Homo sapiens left Africa around 100,000 years ago, reaching Asia around 70,000 years ago and moving through Egypt and into the Negev Desert. The latest discovery indicates humans made a fairly speedy journey to Australia.

Madjedbebe Edge-ground hatchet head being excavated. Gundjeihmi Aboriginal Corporation 2015.

“New Guinea and Australia were joined at this time of very low sea levels, so they could have entered the continent through either Australia or New Guinea or both,” Clarkson says. “Once they had crossed the ocean gaps they could have walked across the intervening land bridge and all the way to Tasmania.”

This early arrival would have meant humans lived alongside Australia’s megafauna, which included a car-sized wombat and a 6,600 lb marsupial, for up to 20,000 years. Scientists do not know exactly why these huge creatures went extinct, but one theory has been that human arrival in Australia played a role in their demise.

The new date of human occupation contradicts this theory. Pushing back the age of first Aboriginal occupation to 65,000 years ago lengthens the period of co-existence of humans and megafauna considerably to perhaps 25,000 years or greater,” Clarkson says. “This makes it extremely unlikely that humans rapidly wiped out all of these large animals. It was a gradual process and the end of a very long process of faunal extinctions in this country, more likely linked to climate change. Humans may however have had some small role, though we have no direct evidence for this.”

Homo floresiensis Reconstruction of Homo floresiensis. Modern humans would have lived alongside the "hobbit" species, scientists have said. Karen Neoh/Flickr

It also means humans may have been in contact with H. floresiensis. This extinct species from the Homo genus was first discovered on Flores in 2003. They were dubbed “hobbits” as they stood at just 1.1 meters in height. For many years, scientists debated whether they had evolved separately and somehow ended up on Flores, or if it evolved from Homo erectus—becoming much smaller due to limited resources. Some scientists suggested it was a deformed human.

Scientists now largely agree H. floresiensis likely came from an early ancestor from Africa and was not connected to H. erectus, as previously thought. This species, however, lived between 50,000 and 190,000 years ago—meaning the first humans in Australia may have come across them at some point.

“It means humans and Homo floresiensis co-existed in the Island Southeast Asia region for thousands of years, but we have no idea if they made contact or not,” Clarkson says. “Humans may have skirted islands on which floresiensis was living. We don't know at this stage if modern humans eventually brought about their demise or not.”

Researchers now plan to re-excavate other archaeological sites in the region to see if they can duplicate the ages seen at Madjedbebe. “Similar kinds of artefacts are known from the base of these sites, so it is very likely they also date to 65,000 years ago,” he says.

In a related News & Views article, Curtis Marean, from Arizona State University, said the findings remind us that Australia “could reveal many other secrets” that will increase our understanding of human colonization and its impact on the environment.

“We now know that modern humans, after they left Africa around 70,000 years ago, dispersed rapidly to a coastal area that became the departure gate for their journey to Australia,” he wrote. “From that launch pad, perhaps some of them envisaged other lands across the water that they could not see. They decided to take a chance and built boats, loading them with both new and tested technologies. Then, with their families, they boarded to embark on a journey of discovery. Sounds familiar—sounds like humans reaching for the stars.”
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Fossils Reveal the First Humans Emerged 170,000 Years Earlier than We Thought
« Reply #1 on: September 29, 2017, 05:15:02 PM »
http://www.newsweek.com/first-modern-humans-homo-sapiens-emerged-africa-674163

 Tech & Science
Ancient Fossils Reveal the First Humans Emerged 170,000 Years Earlier than We Thought
By Hannah Osborne On 9/29/17 at 6:38 AM


Homo sapiens skull. Representational image. Jim Hickcox/Flickr

The first modern humans may have emerged up to 350,000 years ago—170,000 years earlier than previously thought. Analysis of ancient DNA has allowed scientists to trace back the ancestry of people from South Africa to determine when our ancestors split from other hominin species. Their findings consistently point to an early date of divergence, between 350,000 and 260,000 years ago.

How and when modern humans first emerged as a species is a major unanswered question in paleoanthropology because the fossil record is incomplete. At present, the oldest human remains we have date back 195,000 years. But these are not necessarily the first ever Homo sapiens—and the origin of our ancestry remains a mystery.

In a study published in Science, a team of researchers led by Marlize Lombard, from the University of Johannesburg, South Africa, looked at the remains of seven individuals who lived in KwaZulu-Natal between 2,300 and 300 years ago. Three of these lived during the Stone Age, while four others lived 300 to 500 years ago.

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One of the fossils analyzed, known as the Ballito Bay child, was of hunter gatherer descent and would have lived at a time before any migrants had reached South Africa. As a result, his DNA was unaffected by any genetic mixing from other humans from different parts of Africa or Eurasia.

They were able to use the information from the Ballito Bay child, combined with the other individuals, and compare it to other examples of the ancient genome from different times and places.

Demographic model of African history and estimated divergences. Vertical colored lines represent migration, with down-pointing triangles representing admixture into another group. Southern African hunter-gatherers are shown by red symbols and Iron Age farmers in green symbols. C. Schlebusch et al. Science (2017)

The findings show modern humans split from earlier groups between 350,000 and 260,000 years ago. "This means that modern humans emerged earlier than previously thought", study author Mattias Jakobsson, a population geneticist at Uppsala University, said in a statement.

Their dating estimates also fit with the fossil record. At least two or three other Homo species are known to have lived in southern Africa during this time. Furthermore, these dates with recent fossil evidence uncovered in Morocco. Scientists found remains from five Homo sapiens individuals that date back to 300,000 years, raising major questions about where the "cradle of humanity" really was.

Study author Carina Schlebusch, also from Uppsala University, said: “Both paleo-anthropological and genetic evidence increasingly points to multi-regional origins of anatomically modern humans in Africa, i.e. Homo sapiens did not originate in one place in Africa, but might have evolved from older forms in several places on the continent with gene flow between groups from different places.”
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World’s earliest evidence of wine-making found in Georgia
« Reply #2 on: November 14, 2017, 06:44:39 AM »
I wonder when the first Beer was Brewed? ???   :icon_scratch:

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http://www.asiaone.com/world/world%E2%80%99s-earliest-evidence-wine-making-found-georgia

World’s earliest evidence of wine-making found in Georgia


PHOTO: AFP
AFP
Nov 14, 2017

MIAMI - The world's earliest evidence of grape wine-making has been detected in 8,000-year-old pottery jars unearthed in Georgia, making the tradition almost 1,000 years older than previously thought, researchers said Monday.

Before, the oldest chemical evidence of wine in the Near East dated to 5,400-5,000 BC (about 7,000 years ago) and was from the Zagros Mountains of Iran, said the report in the Proceedings of the National Academy of Sciences (PNAS), a peer-reviewed US journal.

The world's very first wine is thought to have been made from rice in China around 9,000 years ago.

"We believe this is the oldest example of the domestication of a wild-growing Eurasian grapevine solely for the production of wine," said co-author Stephen Batiuk, a senior research associate at the University of Toronto.

Scientists on the team came from the United States, Canada, Denmark, France, Italy, Israel and Georgia. They have been working for the past four years to re-analyse archeological sites that were found decades ago.

The fragments of ceramic casks, some decorated with grape motifs and able to hold up to 80 gallons (300 liters), were found at two archeological sites called Gadachrili Gora and Shulaveris Gora, about 30 miles (50 kilometers) south of the Georgian capital Tbilisi.

Researchers used a combination of the latest mass spectrometry and chromatography techniques to identify the ancient compounds. This chemical analysis "confirmed tartaric acid, the fingerprint compound for grape and wine," said the PNAS report.

Researchers also found three associated organic acids - malic, succinic and citric - in the residue from the eight jars.

This "discovery dates the origin of the practice to the Neolithic period around 6,000 BC, pushing it back 600-1,000 years from the previously accepted date," according to the study.

'SOCIAL LUBRICANT'

The Neolithic period began around 15,200 BC in parts of the Middle East and ended between 4,500 and 2,000 BC.

During this era, the latter part of which coincided with the Stone Age, people were beginning to farm, domesticate animals, make polished stone tools, crafts and weaving, researchers said.

"Pottery, which was ideal for processing, serving and storing fermented beverages, was invented in this period together with many advances in art, technology and cuisine," said Batiuk.

"As a medicine, social lubricant, mind-altering substance, and highly-valued commodity, wine became the focus of religious cults, pharmacopeias, cuisines, economics, and society throughout the ancient Near East," he said.

People in Georgia cultivated the Eurasian grapevine, Vitis vinifera, which likely grew abundantly under environmental conditions similar to modern-day France and Italy.

Batiuk said the domestication of the grape "eventually led to the emergence of a wine culture in the region."

"The Eurasian grapevine that now accounts for 99.9 per cent of wine made in the world today, has its roots in Caucasia."

But this might not be the last word, according to lead author Patrick McGovern, scientific director of the biomolecular archeology project for cuisine, fermented beverages, and health at the Penn Museum in Philadelphia.

McGovern, who co-authored the 1996 Nature study that placed the earliest evidence for grape wine in Iran, said the search for the truly oldest artifacts will continue.

"Other sites in the South Caucasus in Armenia and Azerbaijan might eventually produce even earlier evidence for viniculture than Georgia," McGovern said.

"The Taurus Mountains of eastern Turkey are also a prime candidate for further exploration with its monumental sites at Gobekli Tepe and Nevali Cori at the headwaters of the Tigris River," dating as far back as 9,500 BC.
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Re: World’s earliest evidence of wine-making found in Georgia
« Reply #3 on: November 14, 2017, 07:04:32 AM »
I wonder when the first Beer was Brewed? ???   :icon_scratch:
RE

I think the official record is about 4K years ago in Sumer. They had a goddess of beer, which would not be a bad gig.

Stands to reason that given the vagaries of fermentation, the actual history of beer is twice as ancient, at least.
"It is difficult to write a paradiso when all the superficial indications are that you ought to write an apocalypse." -Ezra Pound

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Can you imagine what it must have been like to be the first Homo Sap in India 385K years ago?  Totally pristine nature.  Fresh water everywhere.

Then something went wrong...


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https://www.nature.com/articles/nature25444

Early Middle Palaeolithic culture in India around 385–172 ka reframes Out of Africa models


    Kumar Akhilesh, Shanti Pappu, Haresh M. Rajapara, Yanni Gunnell, Anil D. Shukla & Ashok K. Singhvi

    Nature volume 554, pages 97–101 (01 February 2018)
    doi:10.1038/nature25444
    Download Citation
        ArchaeologySocial sciences

Received:
    15 June 2017
Accepted:
    09 December 2017
Published online:
    31 January 2018

Abstract

Luminescence dating at the stratified prehistoric site of Attirampakkam, India, has shown that processes signifying the end of the Acheulian culture and the emergence of a Middle Palaeolithic culture occurred at 385 ± 64 thousand years ago (ka), much earlier than conventionally presumed for South Asia1. The Middle Palaeolithic continued at Attirampakkam until 172 ± 41 ka. Chronologies of Middle Palaeolithic technologies in regions distant from Africa and Europe are crucial for testing theories about the origins and early evolution of these cultures, and for understanding their association with modern humans or archaic hominins, their links with preceding Acheulian cultures and the spread of Levallois lithic technologies2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20. The geographic location of India and its rich Middle Palaeolithic record are ideally suited to addressing these issues, but progress has been limited by the paucity of excavated sites and hominin fossils as well as by geochronological constraints1,8. At Attirampakkam, the gradual disuse of bifaces, the predominance of small tools, the appearance of distinctive and diverse Levallois flake and point strategies, and the blade component all highlight a notable shift away from the preceding Acheulian large-flake technologies9. These findings document a process of substantial behavioural change that occurred in India at 385 ± 64 ka and establish its contemporaneity with similar processes recorded in Africa and Europe2,3,4,5,6,7,8,10,11,12,13. This suggests complex interactions between local developments and ongoing global transformations. Together, these observations call for a re-evaluation of models that restrict the origins of Indian Middle Palaeolithic culture to the incidence of modern human dispersals after approximately 125 ka19,21.

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Acknowledgements

S.P. and K.A. thank the Sharma Centre for Heritage Education, the L. S. B. Leakey Foundation, the Earthwatch Institute, the Homi Bhabha Fellowships Council (S.P.: 2000–2002; K.A.: 2014–2016) and the ISRO-GBP program for funding various aspects of the research project, and the Archaeological Survey of India and Department of Archaeology, Government of Tamil Nadu, for issuing licenses. Y.G. benefited from an Institut Universitaire de France grant for field and analytical work. A.K.S. acknowledges the Department of Science and Technology and the Department of Atomic Energy, India, for a J. C. Bose national fellowship and for Raja Ramanna fellowships, respectively. H.M.R. was supported by the contingency grant of the J. C. Bose fellowship awarded to A.K.S. S.P. and K.A. thank M. Taieb for his encouragement.
Author information
Affiliations

    Sharma Centre for Heritage Education, 28 Ist Main Road, C.I.T. Colony, Mylapore, Chennai 600004, Tamil Nadu, India
        Kumar Akhilesh & Shanti Pappu
    Department of Physics, Electronics and Space Science, Gujarat University, Navrangpura, Ahmedabad 380009, India
        Haresh M. Rajapara
    AMOPH Division, Physical Research Laboratory, Navrangpura, Ahmedabad 380009, India
        Haresh M. Rajapara & Ashok K. Singhvi
    Université de Lyon, Department of Geography, UMR 5600 Environnement Ville Société, 5 Avenue Pierre Mendès-France, F-69696 Bron, France
        Yanni Gunnell
    Geosciences Division, Physical Research Laboratory, Navrangpura, Ahmedabad 380009, India
        Anil D. Shukla

Contributions

K.A. and S.P. direct the project, are researching ATM and neighbouring sites and analysed the lithic artefacts; H.M.R., A.D.S. and A.K.S. were responsible for the luminescence sampling and dating; Y.G. analysed the geomorphology and palaeoenvironmental evidence at the site. All authors contributed to the writing of the manuscript.
Competing interests

The authors declare no competing financial interests.
Corresponding author

Correspondence to Shanti Pappu.

Reviewer Information Nature thanks K. Fitzsimmons, M. Petraglia and E. Rhodes for their contribution to the peer review of this work.

Publisher's note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Extended data
Extended data figures

    1.
    Distribution of Acheulian, Middle Palaeolithic and Late Palaeolithic sites currently under investigation in the immediate vicinity of ATM, north-eastern Tamil Nadu.
    2.
    General view of excavated trenches and in situ artefacts.
    3.
    Artefacts from layer 5, trench T7A.
    4.
    Representative artefacts from layers 2–4 and unit 5a, in trenches T7A, T7B and T7C.
    5.
    Close-up images of tanged artefacts.
    6.
    Blade cores with close-up images that illustrate generations of blade scar removals.
    7.
    Details of artefact dimensions.
    8.
    Levallois cores from ATM.
    9.
    Pre-heat plateau test for sample ATSP#2013/12L1.
    10.
    Results of pIR-IRSL analyses at ATM.

Supplementary information
PDF files

    1.
    Supplementary Information

    This file contains Supplementary Text, Supplementary Tables 1-4 and Supplementary References.
    2.
    Life Sciences Reporting Summary
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🐵 Tracing the tangled tracks of humankind's evolutionary journey
« Reply #5 on: February 15, 2018, 02:03:54 AM »
https://www.theguardian.com/news/2018/feb/12/tracing-the-tangled-tracks-of-humankinds-evolutionary-journey

Tracing the tangled tracks of humankind's evolutionary journey
Evolution
The briefing

The path from ape to modern human is not a linear one. Hannah Devlin looks at what we know – and what might be next for our species

Hannah Devlin Science correspondent
@hannahdev

Mon 12 Feb 2018 00.51 EST
Last modified on Wed 14 Feb 2018 16.33 EST

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Our ancestry is still not entirely clear, although there is strong evidence for specimens such as Ardipithecus ramidus, centre, being a direct ancestor or very close to our lineage.
Our ancestry is still not entirely clear, although there is strong evidence for specimens such as Ardipithecus ramidus, centre, being a direct ancestor or very close to our lineage. Illustration: Getty, Guardian Design Team

Let’s go back to the beginning. When did we and our ape cousins part ways?
Scientists are still working on an exact date – or even a date to within a million years. Like many of the big questions in human evolution, the answer itself has evolved over the past few decades as new discoveries, techniques and technology have provided fresh insights.

Genetics has proved one of the most powerful tools for time-stamping the split with our closest living relative, the chimpanzee. When our complete genomes were compared in 2005, the two species were found to share 98% of their DNA. The differences hold important clues to how long our lineages have been diverging. By estimating the rate at which new genetic mutations are acquired over generations, scientists can use the genetic differences as a “molecular clock” to give a rough idea of when the split occurred. Most calculations suggest it was between four to eight million years ago.
We share 98% of our DNA with chimpanzees.
We share 98% of our DNA with chimpanzees. Illustration: Getty, Guardian Design Team

This time window is more recent than was originally thought. In the 1960s, fossil evidence led palaeontologists to conclude that a 14m-year-old ape, Ramapithecus, was the earliest ancestor on the human line, based on the shape of its jaw. Subsequent DNA analysis has revealed the split occurred long after that – Ramapithecus is now considered an orangutan ancestor.

So are scientists still looking for the “missing link” between us and other ape species?
We still don’t know the identity of our most recent common ancestors with chimpanzees. But scientists tend to dislike the phrase “missing link”, as it implies that evolution proceeds in an orderly, linear fashion with well-defined junctures.

“It gives the sense that there is a single transitional form that magically bridges the gap between a living ape and a living human and suggests we’ve got to fit everything into our line of evolution,” says Chris Stringer, head of human origins at the Natural History Museum.
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The reality is messier: different branches evolve at different rates; new traits can emerge several times independently; splits can be dragged out over millennia and across continents, with populations diverging and then interbreeding again. Rather than the tree of life it’s more like a dense, thorny bush.

But can we assume that our last shared ancestor with other living apes was something like a chimp?
Not necessarily – chimps are not simply unevolved versions of us. Our hypothetical common ancestor would have had a mixture of chimp-like traits, human-like traits and primitive traits that both species eventually left behind. The common ancestor might have walked on all fours, or might have been more upright.

Scientists are still trying to piece together this evolutionary jigsaw puzzle based on a shifting cast of creatures that show up in the fossil record. To complicate things, most of the fossils found probably represent evolutionary side-branches rather than direct ancestors.
Quick guide
Evolutionary timeline

What are some of the important fossils I should know about?
One of the earliest specimens that people believe lies on our lineage – or not far from it – is Sahelanthropus tchadensis, a six to seven-million-year-old fossil found in Chad. It has an ape-like sloping face, prominent brow and very small brain, but small human-like canine teeth. The spinal cord is positioned underneath the skull, rather than towards the back, which some say suggests the creature walked on two legs, but it’s hard to know for sure, since there’s just a skull and a few bones to go on.

Another fossil from around the same period found in Kenya, called Orrorin tugenensis (nicknamed Millennium Man), also features small teeth and a leg bone that indicates primitive bipedalism.
Ardipithecus ramidus had a grasping big toe, suggesting she would have been an agile climber.

Ardipithecus ramidus had a grasping big toe, suggesting she would have been an agile climber. Illustration: Getty, Guardian Design Team

Slightly later, at 4.4m years, there is Ardipithecus ramidus (Ardi), a stunningly complete female skeleton found in Ethiopia. Ardi, who had a stocky frame and stood almost four feet (one metre) tall, had gangly ape-like arms and grasping big toe, suggesting she would have been an agile climber. Scientists are divided on the extent to which Ardi walked upright – some say she would have walked on two legs routinely, others think she would have just about managed it if she needed to use her arms to carry something. The pelvis bones are crushed and the skeleton does not include a knee, which could have helped resolve the question more definitively. The strongest evidence for Ardi being a direct ancestor, or very close to our lineage, comes from her teeth, which were small and stubby – more like modern human teeth – and lacked the large fang-like canines of chimpanzees, gorillas and earlier extinct apes.

Then comes “Lucy”, a 3.18m-year-old skeleton, named after the Beatles song Lucy in the Sky with Diamonds, the soundtrack to the 1974 excavation. Lucy is viewed as one of the most important discoveries in palaeontology as she is a unique amalgam of primitive features – a chimpanzee-sized brain, a powerful jaw and long, dangling arms – and incredibly human ones. In particular, her legs, knee and pelvis are strikingly similar to our own anatomy, suggesting that by this point our ancestors had gained the distinctive human abilities of being able to walk and run.
Australopithecines appeared about four million years ago, and had brains about the size of a chimpanzee’s.

Australopithecines appeared about four million years ago, and had brains about the size of a chimpanzee’s. Composite: Getty, Guardian Design Team

Lucy also helped cement a growing acceptance of Africa as the cradle of humanity, reflected in her species’ scientific name: Australopithecus afarensis. Scientists now think that the australopithecine genus (in the taxonomical hierarchy, genus is one up from species) gradually evolved and spread across southern and eastern Africa – and that one of these species seeded the next phase of our evolution.

Why did our ancestors start walking upright?
The traditional “savannah theory” held that shifts in the climate led to dense forests being replaced by sweeping grasslands, creating a new incentive for being able to travel long distances by foot. Yet the transition towards bipedalism appears to have started at least six million years ago – long before the African climate dried out enough to create savannahs. To complicate matters further, a recent analysis of the Lucy fossil suggests that multiple fractures had been sustained shortly before her death, leading some to speculate that she may have died falling out of a tree.

A more recent idea is that bipedalism first emerged in the forests, which would be consistent with the fossil record and may also have a modern-day parallel. Orangutans in Sumatra have been observed moving through the forest canopy by walking along branches on two legs while using their arms to help support their weight or hang, allowing them to move through thinner branches than would otherwise be possible.

Whatever prompted our transition from four legs to two, it seems to have happened over millions of years, probably with a long period of travelling between the ground and the trees.

So once we got the hang of walking, what happened next?
The boundary for when our ancestors started counting as human is blurry and somewhat subjective, but scientists place the starting point at species that emerged about 2.4m years ago, which are designated to the Homo genus. We are the sole survivors of this group, but the Earth was once home to a surprising diversity of humans, some of whom crossed paths with our own ancestors.

One of the earliest of these is Homo habilis, who lived in Africa between 2.4m and 1.4m years ago. The name means “handyman” because this species was originally thought to represent the first maker of stone tools (since then, sharpened stones, hammers and anvils dating to 3.3m years ago have been discovered). Homo habilis was short (between one and 1.4 metres or 3ft 4in - 4ft 5in) had a protruding face and massive teeth – earning one fossil the nickname Nutcracker Man. His braincase was about 50% bigger than that of the Australopithicenes, but still only half as big as a modern human’s.
Mastery of fire and cookery may have influenced changes in jaw shape.
Mastery of fire and cookery may have influenced changes in jaw shape. Illustration: Getty, Guardian Design Team

Homo erectus, 1.7-1.8m years ago, was much closer to modern humans anatomically. He was taller (1.5 to two metres or 4ft 9in - 6ft 1in) and bigger-brained than Homo habilis and had a far smaller jaw and teeth, implying a change in diet. Harvard anthropologist Richard Wrangham argues that the striking change in jaw anatomy suggests Homo erectus mastered fire and began cooking, allowing more efficient foraging and digestion, freeing up energy to fuel a larger brain. Homo erectus has sometimes been called the first cosmopolitan, due to the impressive geographical range it spanned, with fossils found in Africa, Spain, Italy, China and Indonesia.

The earliest evidence of Homo sapiens (that’s us) comes from fossils dated to just over 300,000 years ago excavated from a cave in Morocco. The bones of at least five people were found alongside tools, gazelle bones and lumps of charcoal. Jean-Jacques Hublin, a scientist at the Max Planck Institute for Evolutionary Anthropology in Leipzig who excavated the fossils, told the Guardian last year: “The face of the specimen we found is the face of someone you could meet on the tube in London.”
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When did humans leave Africa and spread across the globe?
Until recently, converging lines of evidence from fossils, genetics and archaeology suggested that modern humans first spread from Africa into Eurasia about 60,000 years ago. However, a series of recent discoveries – including a trove of 100,000-year-old human teeth found in a cave in China, and a nearly 200,000-year-old jawbone in northern Israel – show that Homo sapiens was venturing across the world far earlier than once thought.

However, these early exits appear to have contributed very little to the genetics of modern day populations – perhaps these groups died out or were killed off by subsequent migratory waves. By triangulating the common ancestors of modern day populations, scientists can show that the ancestors of African and non-African people alive today converge at around 60,000 years ago. As these ancestors travelled across continents they would have encountered a motley assortment of other archaic human species, including the Neanderthals in Eurasia, the Denisovans in Siberia, possibly a dwarf species known as “the hobbit” (Homo floresiensis) on the Indonesian island of Flores and probably other species that we do not yet know about.
Human evolution has not been a neat or linear process.
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Human evolution has not been a neat or linear process. Composite: Getty, Guardian Design Team
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Did we kill off the Neanderthals?
Neanderthals tend to be cast as the low-browed thugs of the prehistoric world, who stood little chance against the superior intellect and hunting prowess of our own ancestors. This may be a case of unfair stereotyping, though. Neanderthals had bigger brains than us, they made jewellery, buried their dead in ancient ceremonies and used pigments – possibly for tribal markings.

It is true, however, that the Neanderthals went into a steep decline around 40,000 years ago, at a time when Homo sapiens from Africa were settling in Eurasia. Perhaps they were struggling to compete for resources, were killed in conflicts or were simply less well adapted to changes in climate that led our own ancestors to move north and east.

There’s a postscript to this story. While the Neanderthals died out as a species, in one sense they are still around today. Interbreeding between modern humans and Neanderthals means that all non-Africans alive today carry about 1-5% Neanderthal DNA. Everyone has acquired slightly different parts of the Neanderthal genome and so collectively there is a substantial fraction (at least 20%) of the Neanderthal genome spread through the living human population.

Wait ... we interbred with another species?
Yes, genetics shows that the ancestors of everyone outside of Africa interbred with Neanderthals, probably more than once. There was also interbreeding with another archaic group called the Denisovans. We don’t know much about what these other ancient cousins looked like as their fossils are so fragmented. But from a finger bone found in a cave in Siberia, scientists were able to extract high quality DNA belonging to a Denisovan girl who lived about 41,000 years ago.

Intriguingly, Denisovan DNA shows up only in modern day Indigenous Australians and Papua New Guineans, suggesting that their ancestors must have met the Denisovans on their way across the globe, probably somewhere in south-east Asia.

We can only speculate on the circumstances of these interbreeding events and whether they were peaceful mergers of different tribes or violent encounters.
The Earth was once home to a surprising diversity of humans, some of whom crossed paths with our own ancestors.
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The Earth was once home to a surprising diversity of humans, some of whom crossed paths with our own ancestors. Illustration: Getty, Guardian Design Team

Could we use cloning to bring our extinct cousins back to life?
Theoretically, it would be possible to cut and paste Neanderthal or Denisovan mutations into a modern human genome, and then transfer that into an egg and grow a baby using a surrogate mother. In his book Regenesis: How Synthetic Biology Will Reinvent Nature and Ourselves, Harvard geneticist George Church speculates about the possibility of using genetic engineering to resurrect extinct creatures. “If society becomes comfortable with cloning and sees value in true human diversity, then the whole Neanderthal creature itself could be cloned by a surrogate mother chimp – or by an extremely adventurous female human,” Church wrote.
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In a less ethically fraught version of this experiment, scientists at several labs are currently growing Neanderthalised cells and even organoids – miniature brains and livers – to better understand how Neanderthal biology differed from our own.

When did we learn to speak?
This is tricky, as language leaves no direct trace on the fossil record and even today’s neuroscientists haven’t fully figured out how the human brain produces language. Some argue that primitive versions of language pre-date Homo sapiens, based on early evidence of collective hunting and other sophisticated behaviours. For instance, Boxgrove Man, a 500,000 year old Homo heidelbergensis fossil (another extinct relative), was found alongside the remains of now extinct species of rhinoceros, bears and voles, which had signs of having been butchered.

The so-called language gene FOXP2, known to be crucial for speech, also holds clues. The Homo sapiens version of this gene has mutations that are not seen in chimps or other animals. We now know that Neanderthals shared these same mutations. However, modern humans have double the number of mutations in FOXP2’s flanking DNA that determines when the gene is switched on and off, hinting that we could have evolved a qualitatively different capacity for language than our relatives.
What next?

Human evolution is not over, but it’s impossible to predict how we’re going to turn out. It’s tempting to assume that we are on an ever-upward intellectual trajectory, but there’s no guarantee of this. In fact, the human brain has become about 5-10% smaller during the past 20,000 years. Perhaps this is comparable to the pattern seen in domestic animals, which almost always have smaller brains than their wild counterparts. “Maybe we’ve domesticated ourselves and those bits of the brain that our ancestors needed aren’t so important any more,” says Stringer.

It’s also possible that we are swapping individual brainpower for collective forms of intelligence. “Our brains are energetically very expensive – they use about 20% of our energy,” says Stringer. “So if evolution can get away with a smaller brain it will.”
Further reading

Evidence as to Man’s Place in Nature by Thomas Huxley

Lucy: The Beginnings of Humankind by Donald Johanson and Maitland Edey

Our Human Story by Louise Humphry and Chris Stringer

Regenesis: How Synthetic Biology Will Reinvent Nature and Ourselves by George Church

A Brief History of Everyone Who Ever Lived: the Stories in Our Genes by Adam Rutherford
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