It seemed a simple story once. Out of the mud, God shaped a man. Or, life grew, and the millennia passed, and life grew more complex, from bacteria to sponges to trilobites to dinosaurs (omitting myriad steps!), until at last, a primate stood on its two feet and started growing a bigger and bigger brain. What a work of art is Man! (that was irony).
Bad enough we had to look at chimpanzees as distant cousins with whom we once shared a distant ancestor, but clearly no one ever came close to our own perfection.
The story turns out rather more complex (though if you put human arrogance aside, rather more plausible). There have been other hominid (human-like) species. In fact, the evolutionary "ladder of progress" turns out to be more like a bush. We've found bones for maybe 20 hominid species. Which raises, of course, a number of questions.
Like, is Homo sapiens the only one left because it is so superior to the others, or are we just last? (bear in mind Homo sapiens hasn't been around that long) or maybe lucky?
Like, are we the only hominid species still around? (think Bigfoot, think Yeti)
If you think we won out because we're so superior, check out the Neanderthal story. If you think it's out of the question that other hominids could have co-existed with humans without us knowing, check out Flores Man.
Sterkfontein Caves produce 2 new hominin fossils
Two new hominin fossils have been found in the Sterkfontein Caves, in South Africa. The finger bone and a molar, are part of a set of four specimens which are associated with early stone tools dated to 2.18 million years ago.
The proximal finger bone is significantly larger and more robust than any other hand bone of any hominin yet found in South African plio-pleistocene sites. It shows an intriguing mix of modern and archaic features. Similar in shape to the partial specimen from Olduvai Gorge that has been called Homo habilis, it is much larger. The tooth also resembles those from H. habilis, as well as aspects of H. naledi specimens.
The two other hominin fossils found are still being studied.
Sterkfontein remains the richest Australopithecus-bearing locality in the world and continues to yield remarkable specimens. The underground network of caves extends over 5kms, with very few of the deep layers having been systematically excavated.
Australopithecus Sediba not a nutcracker after all
February 09, 2016
New analysis of the tooth and jaw structure of Australopithecus sediba challenges the argument that this hominin ate a woodland diet, including hard foods mixed in with tree bark, fruit, leaves and other plant products.
The new study concludes that A.sediba, unlike other members of the Australopithecus genus, lacked the mechanical force to crack open nuts and other very hard foods. This limitation in biting force is is something A.sediba shares with modern humans, strengthening the case that A.sediba is the australopith ancestor that humans are descended from.
At the least, this indicates that some changes in the environment led to a divergence in diet that was significant for the evolution of our line.
Spanish primate fossils cause rethink on ape split
October 31, 2015
A set of primate fossilised remains found in Spain and dated to 11.6 million years ago, seems to have lived before the split between great and lesser apes occurred. This suggests that either the two branches of apes co-existed or that instead of lesser apes evolving from great ones, it was the other way round.
The fossils also suggest that the last common ancestor of apes and humans may have been much smaller than previously believed. P. cataloniae was as small as the smallest modern gibbons, with both gibbon-like and monkey-like features.
Whether or not the small animal was a descendant of a common ancestor of humans and lesser apes, its discovery in Spain could turn out to be the first evidence that lesser apes migrated from Africa to Europe.
Discovery of jaw sheds light on early Homo
A fossil lower jaw found in the Afar Regional State, Ethiopia, pushes back evidence for the Homo lineage to 2.8 million years ago, 400,000 years earlier than previous finds, and only 200,000 years after the last known occurrence of Australopithecus afarensis ("Lucy") from the nearby Ethiopian site of Hadar.
The jaw reveals advanced features, for example, slim molars, symmetrical premolars and an evenly proportioned jaw, that distinguish early species on the Homo lineage from the more apelike early Australopithecus. But the primitive, sloping chin links the jaw to a Lucy-like ancestor.
Global climate change that led to increased African aridity after about 2.8 million years ago is often hypothesized to have stimulated species appearances and extinctions, including the origin of Homo.
Chinese Homo erectus cranium dated to 1.63 million years ago
November 28th, 2014
New evidence has extended the estimated age of the Lantian Homo erectus cranium from Gongwangling, Lantian County, Shaanxi Province, China, by half a million years.
Earlier estimates dated this important fossil, found in 1964, to 1.15 million years ago. At 1.63 million years ago, this becomes the oldest fossil hominin cranium known in northeast Asia, and the second oldest site with cranial remains outside Africa (the oldest is the Dmanisi crania from Georgia, dated at around 1.75 million years old).
The new date for the Lantian cranium provides good evidence that small-brained hominins moved rapidly eastwards in a warm period just after 1.75 million years ago. The presence of fossils much further south, in Indonesia, that are only slightly younger (c. 1.5 – 1.6 million years ago), also opens up the possibility that hominins followed northern and southern dispersal routes from Africa into Asia.
New Paranthropus boisei fossils change ideas
January 22nd, 2014
The partial skeleton of an early hominin, called Paranthropus boisei, has been found in Tanzania. It's been dated to 1.34 million years ago.
P. boisei was a long-lived species of archaic hominin that first evolved in East Africa about 2.3 million years ago. Until now, only parts of skulls belonging to this species have been found. In the absence of evidence of other skeletal remains, it was commonly assumed that the skeleton of P. boisei was like that of more ancient species of the genus Australopithecus, from which P. boisei likely evolved.
An exceptionally large humerus bone suggests Paranthropus had large forearms designed for tree-climbing, while its large molar teeth suggest it would also have spent a lot more time on the ground than some of its tree-dwelling ancestors. This male probably stood 3.5 to 4.5 feet tall and is estimated to have weighed about 60 kg, significantly heavier than previous estimates from a specimen thought to be a female. The femur and humerus showed similarities with Homo erectus, which may have lived around at the same time as Paranthropus, and may have evolved from the same ancestor.
'Ardi' skull reveals links to human lineage
January 6th, 2014
One of the most hotly debated issues in current human origins research focuses on how 4.4 million-year-old Ardipithecus ramidus is related to the human lineage. "Ardi" was an unusual primate, with a tiny brain and a grasping big toe used for clambering in the trees, and small, humanlike canine teeth and an upper pelvis modified for bipedal walking on the ground.
Now a study of the underside (base) of a beautifully preserved partial cranium has revealed a pattern of similarity that links Ardi to Australopithecus and modern humans and but not to apes.
The human cranial base differs profoundly from that of apes and other primates, and Ardi's cranial base shows the distinguishing features that separate humans and Australopithecus from the apes. The new finding shows that the human cranial base pattern is at least a million years older than Australopithecus afarensis.
Fossils indicate common ancestor for monkeys and apes
June 4th, 2013
The oldest known fossils from two major primate groups, Old World monkeys and apes, have been found in the Rukwa Rift Basin in southwestern Tanzania. Precise geological dating of nearby rocks indicates that the lone tooth and a jaw fragment with three teeth are 25.2 million years old, several million years older than any other example from either primate group.
The finding is consistent with the molecular clocks, that suggest that Old World monkeys and apes split from their common ancestor 25 million to 30 million years ago.
Previous geological evidence suggests that tectonic activity in the East African rift system during the late Oligocene may have helped to trigger the evolutionary divergence between Old World monkeys and apes.
Australopithecus sediba more closely related to humans than thought
April 11th, 2013
New research has pieced together a comprehensive picture of how the hominid Australopithecus sediba moved, and opens up bigger questions about how this hominid is related to humans.
The analysis is based on two individuals dated to 1.977 to 1.98 million years in age. It reveals that Au. sediba had a human-like curvature of the lower back, but it was functionally longer and more flexible than that of modern humans. The strong lumbar curvature suggest similarities with the Nariokotome Homo erectus skeleton. This suggests a 'compromise' form of bipedalism for a hominin that still partially relied on climbing trees.
Dental traits suggest the species is distinct from east African australopiths, but is close to Au. Africanus. Of 22 telling dental traits considered, Au. sediba shared 15 with Australopithecus africanus (dated to between 3.03 and 2.04 million years ago) and 13 with Homo erectus. Sediba and africanus shared five dental traits that weren't found in earlier australopiths, and five traits with early humans (Homo habilis/rudolfenis and Homo erectus)which weren't shared with earlier ancestors.
Both africanus and sediba are therefore more closely related to humans than the famous "Lucy" skeleton fossil, belonging to Australopithecus afarensis and dated to 3.2 million years ago, that was at one time was thought to be the closest relative of humans.
Analysis of the mandibular remains shows they share similarities with other australopiths, but can be differentiated from Au. africanus in both size and shape, and growth trajectory.
Analysis of the upper limb bones shows they are largely primitive, sharing with other australopiths an upper limb that was well-suited for arboreal or other forms of climbing and possibly suspension. However, its hands and wrists are remarkably like those of humans.
The rib cage shows a narrow upper thorax like that of the large-bodied apes, and unlike that of humans, but the less well-preserved elements of the lower rib cage suggest a degree of human-like narrowing to the lower thorax. The narrow upper body suggests a small lung capacity.
The anatomies of the heel, mid-foot, knee, hip, and back show that Au. sediba would have walked very differently than modern humans, with the the outer edge of the foot being the first part to strike the ground, followed by a roll inwards, causing a tremendous amount of rotation at each of the leg joints. The result would be a shuffling, swaggering, flat-footed gait with short strides. The not-very-efficient mode of walking was probably a compromise with tree-climbing abilities.
This gait is different from that shown by A. Afarensis (in 3.6 million year old footprints), giving us three different forms of bipedal walking. This suggests that upright walking may have evolved more than once.
The differences in the feet also reduce the likelihood that A. Afarensis is ancestral to A. sediba.
Although the A. sediba fossils are contemporaneous with H. habilis, the species could still be ancestral to the Homo lineage, depending on how far back they extend.
Australopithecine ancestors walked and climbed trees?
December 31st, 2012
Terrestrial bipedalism is seen as one of the important traits behind the evolution of the Homo lineage. Australopithecus afarensis, 3.5 million years ago, is the first bipedal specimen we have, but had they totally forsaken the trees?
Their rigid ankle and arched, nongrasping foot are widely interpreted as being incompatible with climbing, but a new study comparing two African and two Philippine tribes suggests that feet adapted to terrestrial bipedalism still allows for effective treeclimbing.
The studies in Uganda compared Twa hunter-gatherers to their agriculturalist neighbors, the Bakiga, while in the Philippines, Agta hunter-gatherers were compared to Manobo agriculturalists. Both the Twa and the Agta habitually climb trees in pursuit of honey.
Extreme dorsiflexion (bending the foot upward toward the shin to an extraordinary degree) was seen among these climbers. Ultrasound imaging found that the Agta and Twa had significantly longer calf muscle fibers.
Lao skull earliest example of modern human fossil in Southeast Asia
August 20th, 2012
An ancient skull recovered from a cave in the Annamite Mountains in northern Laos is the oldest modern human fossil found in Southeast Asia, pushing back the clock on modern human migration through the region by as much as 20,000 years. The skull has been dated to between 46,000 and 63,000 years old.
The find is the first fossil evidence that supports genetic studies that indicate that modern humans occupied that part of the world at least 60,000 years ago.
Humans and great apes diverged earlier than thought
August 15th, 2012
Genetic data from both chimpanzees and gorillas has found that the two diverged some time earlier than has been thought.
New calculations using breeding information from 105 gorillas and 226 chimps, plus information from fossilized excrement that contained DNA data, has found that the mutation rate in chimps is slower than that of humans. This means that divergence times were likely off by as much as a million years.
The new data indicate that humans and chimps likely diverged some seven to eight million years ago, rather than the 4-6 million years previously estimated, while the divergence of gorillas (which led to both humans and chimps) came approximately eight to nineteen million years ago (rather than 7-9 million years ago).
This recalculation gives more validity to claims that various fossils purporting to be the earliest members of the human family, such as the 6 million to 7 million-year-old Sahelanthropus tchadensis from Chad, really are hominins.
A. sediba child found in South Africa
July 12th, 2012
The remains of a juvenile Australopithecus sediba (aged 9-13) has been found in South Africa. The "most complete early human ancestor skeleton ever discovered" includes parts of a jaw, a complete femur, ribs, vertebrae and other important limb elements. It's thought to be around two million years old.
Spanish hunter-gatherers' DNA shows links to Northern Europeans
June 28th, 2012
Part of the genome of two individuals living in Spain during the Mesolithic Period, 7000 years ago, has been recovered. The DNA data show that they are not directly connected to current populations of the Iberian Peninsula, but were closer to current populations of northern Europe.
The complete mitochondrial DNA of one of these individuals shows that Mesolithic European populations, from the regions corresponding to the current England, Germany, Lithuania, Poland, and Spain, shared the same mitochondrial lineage.
The remains were found at La Braña-Arintero site, located at Valdelugueros (León), Spain.
Bonobos as closely related to humans as chimps
13 June 2012
The sequencing of the genome of the bonobo has confirmed that it shares the same percentage of its DNA with us as chimps do (98.7%). It also reveals that bonobos and chimpanzees share 99.6% of their DNA.
About 1.6% of our DNA is shared with only the bonobo, but not chimpanzees. A similar amount is shared with only chimps, but not bonobos. The differences suggest that our common ancestor had a quite large and genetically diverse population, numbering about 27,000 breeding individuals.
Some of the small differences in DNA may be involved in the regulation of immune responses, tumor suppression genes, and perception of social cues from urine.
More evidence for Asia, not Africa, as the source of earliest anthropoid primates
June 4th, 2012
A new fossil primate from Myanmar, Afrasia djijidae, illuminates a critical step in the evolution of early anthropoids. The 37-million-year-old Afrasia closely resembles another early anthropoid, Afrotarsius libycus, recently discovered at a site of similar age in the Sahara Desert of Libya.
The close similarity between Afrasia and Afrotarsius is being taken by some to support the idea that Asia, rather than Africa, is the starting point for anthropoid primate evolution.
Details of tooth shape in the Asian Afrasia and the North African Afrotarsius fossils indicate that these animals probably ate insects. The size of their teeth suggests these animals weighed around 3.5 ounces (100 g), roughly the size of a modern tarsier.
DNA confirms Denisovans lived alongside Homo sapiens and Neandertals
November 19, 2015
The sequencing of mitochondrial and nuclear DNA from 50,000-year-old molars found in the Altai mountains in Siberia confirm that the Denisovans lived alongside Homo sapiens as well as Neanderthals.
There was slightly more sequence diversity among Denisovans than among Neanderthals, but less than in modern-day humans.
The differences in mitochondrial DNA from three individuals suggests that the species may have inhabited the region for more than 60,000 years.
Ancient stone tools found in Indonesia point to another archaic group of humans
The discovery of 311 stone tools that are at least 118,000 years old, on the island of Sulawesi in Indonesia, suggests that modern humans arriving there 60,000 years ago would have met an ‘isolated human lineage’. However, no hominid fossils have been found with the tools.
Homo naledi dated to two million years ago
December 07, 2015
A comparative analysis of Homo naledi and other Homo species’ skulls suggests that H.naledi lived two million years ago (plus or minus 500,000 years).
H. naledi was discovered only a few months ago, with the finding of over 1,500 bones in the Rising Star cave in the Cradle of Civilisation World Heritage Site, South Africa. The unusual geologic context of the cave in which they were found has made dating difficult, although researchers have concluded that the fossils indicate the species is one of the oldest members of the homo genus. Although ape like in many respects, H. naledi has several characteristics in common with modern humans.
The analysis also shows that H.naledi is significantly different from the ten other species included in the study, with its skull being most similar to the skulls attributed to Homo habilis, known to date to 1.8 million years ago, and to some extent to Homo rudolfensis, which lived between 2 and 2.5 million years ago.
New human species found in South African cave
A new Homo species, Homo naledi, has been announced, following the 2013 discovery of more than 1 550 numbered fossil elements in a cave known as Rising Star in the Cradle of Humankind World Heritage Site, northwest of Johannesburg, South Africa.
The fossils were found in a chamber about 90 meters from the cave entrance, accessible only through a chute so narrow that a special team of very slender individuals was needed to retrieve them.
So far, parts of at least 15 individuals have been recovered, which is only a small fraction of the fossils believed to remain in the chamber. The individuals include infants, children, adults and elderly individuals.
The species shows a unique combination of human and more primitive characteristics. H. naledi had a tiny brain, about the size of an average orange (about 500 cubic centimeters). On average, he was about 5 feet tall and weighed about 45 kg. His teeth and many skull features resemble those of the earliest-known members of our genus, such as Homo habilis, while the hands suggest tool-makers, although their curvature suggests climbing abilities. The shoulders are ape like, but the feet closely resemble modern humans. Hunched shoulders, powerful hands and thin limbs suggest Homo naledi was built for long-distance walking.
The remains were not found with any other major fossil animals (only a few mouse and bird remains), in a chamber that was isolated from other chambers and never been open directly to the surface. There are no signs on the bones that any scavengers, predators, or natural processes, carried them to this chamber. All of this suggests that these people were intentionally buried. Such behavior has been thought of as unique to humans.
Human body went through four main stages
September 02, 2015
A study of the body shape and size of 430,000 year old fossils collected from the Sima de los Huesos, in Atapuerca in northern Spain, suggests that human body evolution has gone through four core stages that depend on two main concepts: how much time our ancestors spent living in trees as arboreal primates and how much time they spent walking around on the ground on just two legs as modern humans do today.
Compared to Neanderthals, the humans living in Atapuerca had a smaller brain mass relative to body mass, and their bodies were relatively muscular, wide and tall. Many anatomical features were shared between later Neanderthals and the Atapuerca humans that are not found in modern humans.
The Atapuerca humans were in the third of the four stages hypothesized for human evolutionary development. This body type was likely common to many other close relatives like Neanderthals and even earlier members such as Homo erectus; it seems to have been prevalent for around a million years or so.
50,000-year-old bones found in Altai
August 16, 2015
More bones have been found in the Altai Mountains, in different levels dating from 35,000 to 50,000 years or more. The cave, called Strashnaya, is some 125 km from the Denisova cave, where the first fossils belonging to the species now known as the Denisovans were found.
Tools found near one of the bone fragments suggest it may have belonged to a Neanderthal. The Strashnaya cave has yielded Stone Age tools, as well as pottery dating from the Bronze Age to the Middle Ages.
New Australopithecus species found in Ethiopia
Jaw fossils recovered from the Woranso-Mille area of the Afar region of Ethiopia have been assigned to a new species, Australopithecus deyiremeda. With the bones dated to 3.3-3.5 million years ago, the hominin must have lived alongside "Lucy's" species, Australopithecus afarensis, which lived from 2.9 million years ago to 3.8 million years ago.
Australopithecus deyiremeda differs from Lucy's species in terms of the shape and size of its thick-enameled teeth and the robust architecture of its lower jaws. The anterior teeth are also relatively small, indicating that it probably had a different diet.
Gender size difference in Australopithecines comparable to humans
April 28th, 2015
Based largely on Lucy, the first example found of Australopithecus afarensis, it has been thought that males and females were very different in size, like gorillas. However, a new analysis, comparing 41 different specimens to both Lucy and a recently uncovered, also reasonably intact A. afarensis ('Kadanuumuu'), has concluded that the species is in fact within the same range of sexual dimorphism as humans. Lucy and Kadanuumuu probably represent outliers at the lower and upper edge, respectively.
Increase in human body size occurred later than thought
March 26th, 2015
It's been widely thought that it was the increase in body size that enabled the Homo lineage to migrate out of Africa and into Eurasia. Now a new analysis shows that the main increase in body size for the Homo lineage occurred tens of thousands of years after Homo erectus left Africa, and primarily in the Koobi Fora region of Kenya.
The new research, using tiny fragments of fossil from between 2.5 and 1.5 million years ago to estimate our earliest ancestors' height and body mass, indicates that the huge diversity in body size we see in humans today emerged much earlier than previously thought.
The problem in establishing body size is that techniques for calculating the height and body mass of individuals required specific pieces of bone such as the hip joint or most of a leg bone, meaning that calculations were based on small samples of only 10-15 fossils. New equations have enabled a wider range of bones to be used, allowing calculations to be based on over 40 specimens.
The analysis has revealed that the size shift to much heavier, taller individuals occurred primarily in one particular place - in a region called Koobi Fora in northern Kenya around 1.7 million years ago.
Earliest known fossil of the genus Homo dates to 2.8 to 2.75 million years ago
March 4th, 2015
The earliest known record of the genus Homo, represented by a lower jaw with teeth recently found in the Afar region of Ethiopia, has been dated to between 2.8 and 2.75 million years ago.
Other fossils found in this area, such as those of prehistoric antelope, water dependent grazers, prehistoric elephants, a type of hippopotamus and crocodiles and fish, have been dated to between 2.84 to 2.54 million years ago
The fossils suggest that the area was a more open habitat of mixed grasslands and shrub lands with a gallery forest—trees lining rivers or wetlands. The landscape was probably similar to African locations like the Serengeti Plains or the Kalahari. Some researchers suggest that global climate change intensifying roughly 2.8 million years ago resulted in African climate variability and aridity and this spurred evolutionary changes in many mammal lines.
Stone Age skull found in Kenya shows striking diversity
February 21, 2015
A 22,000-year-old skull fragment, found in Kenya, suggests that early humans were much more varied than previously thought. While the bone clearly belongs to an anatomically modern human, it displays marked differences from skulls from the same time found in Africa and Europe. In particular, the skull was relatively thick, possibly as a result of damage, nutritional stress, or a very active childhood.
Early human ancestors used their hands like modern humans
New research supports archaeological evidence for stone tool use among Australopithecus africanus 3-2 million years ago.
The research used new techniques to reveal how fossil species were using their hands by examining the internal spongey structure of bone called trabeculae, which remodels quickly during life and can reflect the actual behaviour of individuals in their lifetime. Australopithecus africanus had a human-like trabecular bone pattern in the bones of the thumb and palm consistent with forceful opposition of the thumb and fingers typically adopted during tool use, as do other non-arboreal and stone tool-making fossil human species, such as Neanderthals.
Ancient human genome from southern Africa throws light on our origins
Mitochondrial DNA from a 2,330-year-old skeleton found at St. Helena Bay, at the southernmost tip of Africa, has revealed that this man, from a lineage now presumed extinct, as well as other indigenous coastal dwellers like him, were the most closely related to ‘Mitochondrial Eve’.
The bones were found in 2010, very close to the site where 117,000 year old human footprints had been found (“Eve’s footprints”). He was 1.5 metres tall, and in his fifties. Shells found with him, and a bony growth in his ear canal known as ‘surfer’s ear’, suggested that he spent some time diving for food in the cold coastal waters.
He lived there before migration into the region, which took place around 2,000 years ago when pastoralists made their way down the coast from Angola, bringing herds of sheep.
Denisovans gave Tibetans advantage at high elevation
July 2nd, 2014
A new genetic study has revealed that Tibetans were able to adapt to high altitudes because of a gene variant picked up from the Denisovans.
An unusual variant of the gene EPAS1, involved in regulating the production of hemoglobin, became widespread in Tibetans after they moved onto the high-altitude plateau several thousand years ago. This variant allowed them to survive despite low oxygen levels at elevations of 15,000 feet or more. This part of the EPAS1 gene is almost identical to the gene in Denisovans and very different from all other humans. It is found in about 87% of Tibetans, and 9% of Han Chinese (who share ancestry).
Climate change critical for human evolution
July 3rd, 2014
A new approach to integrating paleoclimate data, new fossils and understandings of the genus Homo, archaeological remains and biological studies of a wide range of mammals (including humans), has led researchers to conclude that various human traits thought to have evolved at around the same time — a large brain, long legs, the ability to craft tools and prolonged maturation periods — emerged at different points, some of them among our Australopithecus ancestors between 3 and 4 million years ago. Instead, the crucial trait that enabled our ancestors to begin spreading from Africa to Eurasia 1.85 million years ago, was the ability to adjust to changing conditions.
The analysis is based to some extent on the idea that for East Africa, 2.5 million to 1.5 million years ago was a time of strong climate instability and shifting intensity of annual wet and dry seasons. In response, multiple coexisting species of Homo that overlapped geographically emerged.
This is why, it is speculated, adaptability to changing environments, rather than adaptation to any one environment, became such a key trait for the human lineage.
A number of species from this period have been found in recent years, all differing in the shape of their skulls, especially their face and jaws, but not in size. These differences suggest the hominids were tackling slightly different ecological niches.
Tool use and dental evidence also indicates that species of early Homo were more flexible in their dietary choices than other species.
Epigenetic comparisons points to how humans differed from now-extinct cousins
April 22, 2014
A new study has reconstructed the epigenome of the Neanderthal and the Denisovan, and compared them with that of modern humans, identifying genes whose activity had changed only in our own species during our most recent evolution.
Among those epigenetic changes, many are expressed in brain development. Numerous changes were also observed in the immune and cardiovascular systems, whereas the digestive system remained relatively unchanged.
Many of the genes whose activity is unique to modern humans are linked to diseases like Alzheimer's disease, autism and schizophrenia.
Spanish hunter-gatherer shows blue eyes came before lighter skin
26 January 2014
DNA taken from the wisdom tooth of a European hunter-gatherer who lived in Spain around 7,000 years ago, has revealed that the man had blue eyes, black or brown hair, and dark skin, was probably lactose intolerant and had more difficulty digesting starchy foods than farming communities. Challenging the assumption that farming was behind the strengthening of our immune system, the DNA carried mutations that protect the immune system against bacteria and viruses.
The blue eyes were a surprise with the dark skin, because the mutation for blue eyes was thought to have arisen more recently than the mutations that cause lighter skin colour.
The DNA came from the better-preserved of two skeletons found in a deep and complex cave system high up in the Cantabrian Mountains of northwest Spain in 2006. Carbon dating put the remains at around 7,000 years old, before farming had swept into Europe from the Middle East. Ancient artefacts found with them, including perforated reindeer teeth attached to their clothing, supports this dating.
The DNA most closely matched the genetic makeup of people living in northern Europe, in particular Sweden and Finland.
January 22nd, 2014
A new study dates our most common male ancestor ('Adam') to 209,000 years ago, 9,000 years earlier than originally calculated. This puts him within the time frame of 'Eve', the genetic maternal ancestor of mankind.
Bone found in Spanish cave linked to Denisovans
DNA strands from the thigh bone of an early human found with many others in Sima de los Huesos in the Atapuerca mountains in northern Spain, has been dated at 400,000 years old. Tentatively classified as an early form of Neandertals or Homo heidelbergensis, the DNA has surprised researchers by most closely resembling that of Denisovans.
Scientists are now trying to get enough nuclear DNA to analyze, to confirm or otherwise help explain, these surprising results.
Skull of Homo erectus challenges 'bushiness' of early human lineage
A skull found at Dmanisi is the only intact skull ever found of a human ancestor that lived in the early Pleistocene, around 1.8 million years ago. The many diverse remains at Dmanisi are thought to be early forms of Homo erectus. This latest skull belonged to an adult male with a small brain (just under 550 cubic centimetres), a long face and big, chunky teeth.
The odd dimensions of the skull, quite different from others found on the site, prompted the researchers to look at normal skull variation in ancient and modern humans, and chimps. On the basis of these variations, they concluded that the supposedly different species of human ancestor living in Africa at the time (e.g., H rudolfensis, H gautengensis, H ergaster and H habilis) may simply be normal variants of H erectus.
More intact fossils are needed to confirm or deny this hypothesis.
The combination of small brain and big face has not been seen before, and if it wasn't so clear that the jaw and cranium belong together (the teeth match perfectly), they would ordinarily have been assigned to different species. Of course, it's also possible that this is a new species, not H. erectus.
The researchers also challenge the idea that Australopithecus sediba was a direct ancestor of modern humans.
No known hominin is ancestor of Neanderthals and modern humans
October 21st, 2013
A study focusing on the shape of dental fossils has concluded that none of those examined fit the expected profile of the common ancestor of Neanderthals and modern humans, and moreover, that the lines that led to Neanderthals and modern humans diverged nearly 1 million years ago, much earlier than the 350,000 years suggested by other studies. This is based on the finding that the potential human ancestors discovered in Europe are morphologically closer to Neanderthals than to modern humans.
The study compared some 1,200 molars and premolars from 13 species or types of hominins, including Homo heidelbergensis, H. erectus and H. antecessor.
Chinese Middle Pleistocene teeth add new data to evolution of Asian hominins
March 14th, 2013
A comparative analysis of four hominin teeth recovered from the late Middle Pleistocene cave site of Panxian Dadong, Guizhou of southwestern China, has revealed that they combine archaic and derived features that align them with Middle and Upper Pleistocene fossils from East and West Asia and Europe. However, they don't show any typical traits that would allow them to be identified as Neandertal or H. sapiens.
Hominins already inhabited the Three Gorges region of South China in Pleistocene
December 13th, 2012
A review of many hominin fossils and Paleolithic stone artifacts has concluded that there has been a long history of hominin occupation in the Three Gorges region, likely more or less continuous during the Middle to Late Pleistocene, and possibly as far back as the early Early Pleistocene. The stone artifacts are thought to have probably come from archaic and modern Homo sapiens.
New Kenyan fossils indicate other hominids lived in the time of Homo erectus
October 3rd, 2012
Fossils discovered east of Africa's Lake Turkana confirm that there were two additional species of genus Homo living alongside Homo erectus almost two million years ago. The fossils include a face, a complete lower jaw, and part of a second lower jaw.
The three new fossils shed light on a long-standing debate involving a fossil known as KNM-ER 1470, a skull distinguished by its large brain size and long flat face. This fossil, missing its lower jaw and teeth, ignited a longstanding debate about just how many different species of early Homo lived alongside Homo erectus during the long Pleistocene epoch (2.6 million to 11,700 years ago). Was 1470's unusual morphology within the natural variation within a species, or evidence of a separate species, Homo rudolfensis?
The face, KNM-ER 62000, is very similar to that of 1470. The new fossils greatly strengthen the case that two species of early Homo lived alongside Homo erectus: Homo habilis and Homo rudolfensis. They also support the idea that size wasn't a crucial difference between species (which show large variation within the species); rather, different facial anatomies are the crucial variation that enabled them to fit different ecological niches. So, for example, 1470 looks to have been a powerful chewer, enabling him to pursue nuts and tought fruits, perhaps even meat.
The fossils, found within 10km of 1470's location, are dated to between 1.78 million and 1.95 million years old.
Peking Man an isolated population
September 11th, 2012
New 3D scanning techniques on the morphological variations of Peking Man's skulls at Zhoukoudian Locality 1, have found that the skull of the latest inhabitant did increase in every direction as compared to the earliest inhabitant, but the shape remained relatively stable.
This slow evolutionary change over 300,000 years suggest that Peking Man was an isolated population. Over a similar period, hominids in Nanjing showed much greater change.
Six skulls from Peking Man have been discovered at Zhoukoudian Locality 1, in the suburbs of Beijing.
What the Denisovan genome reveals
September 3rd, 2012
The genome of the Denisovans has been decoded from the tiny finger bone and two back teeth found in the Altai Mountains, which are the only known remains of the Denisovans so far found (or at least identified).
The genome reveals that the parents of the Denisovan were genetically very similar, although not related, suggesting a very small population. The girl probably had dark skin, brown hair and brown eyes.
The most recent common ancestor of humans, Denisovans, and Neatherthals, lived about 500,000 years ago. The ancestor of the Denisovans and Neanderthals then developed separately from modern humans, meaning they are more closely related to each other than to humans. Homo sapiens first originated 120,000 to 200,000 years ago.
The most plausible scenario at present is that there were two waves of transmigration out of Africa: the group of prehistoric humans, from which the Neanderthals and Denisovans originated, migrated out of Africa approximately half a million years ago. The Neanderthals settled primarily in Europe to as far away as Central Asia, while the Denisovans lived in East Asia.
Homo sapiens, i.e. modern man, first left the African continent during a second wave of migration fifty to one hundred thousand years ago and moved to East Asia.
Comparison with the genome of the Neandertals and eleven modern humans from around the world confirm previous findings that modern populations from the islands of southeastern Asia share genes with the Denisovans (about 3%, in the case of Papua New Guineans and Australian Aborigines). The genomes of people from East Asia, and South America also include slightly more genes from Neandertals than those of people in Europe (1.8% vs 1%).
About 100,000 changes in the human genome occurred after the split from the Denisovans, although only 260 of them are located in regions that provide information for proteins. Eight of these changes affect genes that are associated with brain function and nervous system development. Another 34 mutations found only in modern humans are associated with diseases, including four that affect the skin and eyes.
Early human ancestors had more variable diet
August 8th, 2012
An analysis of fossil teeth from Australopithecus, Paranthropus and Homo indicates that Australopithecus, a predecessor of early Homo, had a more varied diet than early Homo. Its diet was also more variable than the diet of another distant human relative known as Paranthropus.
Paranthropus had a primarily herbivorous-like diet, while Homo included a greater consumption of meat. Australopithecus probably ate both meat and the leaves and fruits of woody plants. The composition of this diet may have varied seasonally.
The home-range area was of similar size for species of the three hominin genera. All the hominids lived in the same general area. It's suggested that up until two million years ago in South Africa, the Australopithecines were generalists, but gave up their broad niche to Paranthropus and Homo, both being more specialised than their common ancestor.
DNA from living hunter-gatherers sheds light on human variation
26 July 2012
Sequencing the DNA of five individuals from each of three hunter-gatherer groups living in Africa today: the Hadza and Sandawe from Tanzania and the Pygmies from Cameroon, has revealed over 13.4 million genetic variants, 5 million of which had never been seen before. About 72,000 of these variants were in regions of the DNA that code for genes. The rest were in non-coding regions, which may influence how and whether genes are expressed.
Some of these variants are related to smell and taste, suggesting adaptation to specific smells and foods. Others include genes involved in immune system activity and the fat content of breast milk, and genes that produced blood compounds involved in injury repair.
A group of variants unique to the Hadza relate to a protein that responds to the active ingredient in marijuana; interestingly, the Hadza smoke large amounts of marijuana. The Pygmy genome had a unique cluster of 44 variants in a gene called HESX1, which is turned on in embryonic development and controls the growth of the pituitary itself, which is presumably related to their short stature.
Most intriguing of all, the study found genetic evidence that all three groups had intermingled sexually with an unknown, older species at about the same time as European humans were interbreeding with Neanderthals.
While all three have some of the most ancient lineages in the world, there are notable differences between these hunter-gatherer groups: the light-skinned Sandawe have intermarried with agrarian peoples and engage in some agriculture; the dark-skinned Hadza have remained isolated, though living in a similar environment; the Pygmies live in dense jungle.
Foot fossils show bipedalism was an evolving transition
April 5, 2012
The discovery of fossilized feet bones reveals the existence of a previously unknown species of pre-human, and may shed light on how humans began walking upright.
The bones, dated to about 3.4 million years ago, were found in the Afar region of Ethiopia, but though found in the same time and geographical range as Australopithecus afarensis, the foot has characteristics (such as an opposable big toe) that don’t match those of Lucy. The range of movement of the big toe suggests adaptation to climbing and grasping rather than walking on the ground, where it would have produced a somewhat awkward gait.
In other words, at this time, over 3 million years ago, two hominins were displaying contrasting locomotion behavior, showing that the adaptation to bipedality, though considered one of the decisive transitions in early human evolution, was not a single, isolated event.
While the lack of other fossils prevents naming of this other species, the foot is said to be strikingly similar to the earlier hominin Ardipithecus ramidus, nicknamed Ardi, which lived 4.4 million years ago in Ethiopia.
Chinese bones may indicate new human variant
March 15, 2012
Analysis of bones found in caves in Yunnan in China reveals a mix of archaic and modern human characteristics that may indicate a new hominid species, or at least a significant variant. The fossils from at least four individuals, have been dated to between 11,500 and 14,500 years ago. The presence of a great many fossils from giant red deer has given the population the nickname: the Red Deer Cave people.
While having modern facial proportions, they had the broad noses, prominent brow ridges, scant chins, large molar teeth, and thick skull bones characteristic of more primitive Homo species. Cranial scans suggest archaic-looking parietal lobes alongside more modern-looking frontal lobes.
Possibile explanations for this intriguing mix include them being late descendants of an early population of modern humans in Asia, or a very small population that developed the traits through genetic drift, or a hybridisation with another species such as the Denisovans.
Was human evolution caused by climate change?
March 15th, 2012
Models of how animal and plant distributions are affected by climate change may also explain aspects of human evolution, such as why Homo sapiens survived and other human variants did not, and how and why Neanderthals and the Denisovans evolved. A crucial idea is the importance of a subgroup adopting an area of refuge from the harsh climatic conditions of the Ice Age, which led to important evolutionary changes and ultimately a new species.
Gorilla genome sequenced
The first full sequence of the gorilla genome shows that we share 96% of the same genome, and shared a common ancestor 10 million years ago. Some 15% of the gorilla's genetic code is closer between humans and gorillas than it is between humans and chimpanzees, with whom we share more than 98% of our genes and whose lineage split from ours about six million years ago.
The analysis also reveals particular similarities in genes involved in sensory perception and hearing, and brain development showed accelerated evolution in all three species. Of special interest was the finding that the genes associated with hearing are very similar between humans and gorillas, challenging the assumption that changes in hearning are linked to the evolution of language in humans.
November 3, 2011
Earliest Modern Europeans Described
A new analysis of a fragment of human upper jaw bone found in 1927 in Kent’s Cavern in southern England has pushed back its dating from 35,000 years old to between 44,200 and 41,500 years ago. This would make it the oldest evidence for early humans in Western Europe (previous oldest fossils date to just 41,000 to 39,000 years ago), although southeastern Europe has fossils this old. The new date suggests modern humans spread rapidly once they crossed into Europe.
Another reanalysis, this time of two molars from southern Italy originally classified as Neanderthal, have been reclassified as human. The teeth are estimated to be 45,000 to 43,000 years old.
September 22, 2011
DNA study suggests Asia was settled in multiple waves of migration
Analysis of DNA from dozens of present-day populations in Southeast Asia and Oceania, including Borneo, Fiji, Indonesia, Malaysia, Australia, the Philippines, Papua New Guinea and Polynesia, has revealed that, in addition to New Guineans, Denisovans contributed genetic material to Australian aborigines, a Philippine "Negrito" group called Mamanwa, and several other populations in eastern Southeast Asia and Oceania. However, groups in the west or northwest, including other Negrito groups such as the Onge in the Andaman Islands and the Jehai in Malaysia, as well as mainland East Asians, did not interbreed with Denisovans.
The findings indicate that Denisovans interbred with modern humans in Southeast Asia at least 44,000 years ago before Australians and New Guineans separated. The findings also offer genetic support for the hypothesis that Southeast Asia was first colonized by modern humans unrelated to present-day Chinese and Indonesians, and that these and other East Asians arrived in later migrations.
September 22, 2011
Aboriginal Australians: The first explorers
The first genome from an Aboriginal Australian shows that they are descended directly from an early human expansion into Asia that took place some 70,000 years ago, at least 24,000 years before the population movements that gave rise to present-day Europeans and Asians. This is contrary to the previous and most widely accepted theory that all modern humans derive from a single out-of-Africa migration wave into Europe, Asia, and Australia.
The study used DNA from a lock of hair donated to an anthropologist by an Aboriginal man a hundred years ago.
September 19, 2011
Continents influenced human migration, spread of technology
Analysis of human genomes drawn from more than five dozen populations has indicates that orientation seems to explain why technology spread more slowly in the Americas than in Eurasia. The analysis found that populations in North and South America are, for the most part, more different from each other than the populations in Eurasia. That is, genetic difference increased more with latitudinal distance between Native American populations than with longitudinal distance between Eurasian populations. In Eurasia people moved primarily along east-west routes, taking advantage of the relative sameness in climate. But America’s north-south orientation means greater climate variability, making travel between populations less common.
September 19, 2011
CT study of Australopithecus species reveals evolutionary relationships
For decades scientists have disagreed about the significance of facial features shared by a number of Australopithecus species, and in particular two bony columns known as "anterior pillars" that extend up from the canine teeth and bracket the nasal opening.
CT scans of fossil skull fragments from five Australopithecus species have now revealed profound differences in the internal structure of the anterior pillars. In A. africanus the anterior pillar is a hollow column of cortical bone, whereas in A. robustus it is a column of dense trabecular bone. Although A. boisei usually lacks an external pillar, it has internal morphology identical to that seen in A. robustus.
This result supports the view that there was a single evolutionary branch of 'robust australopithecines', and that the A. africanus and A. boisei forms both shared a common ancestor, while the external similarities seen in the South African species (robustus and africanus; boisei is from east Africa) are the result of parallel evolution (perhaps because of a similar dietary niche).
September 8, 2011
New transitional fossils may connect Australopithecus and Homo
New descriptions of Australopithecus sediba fossils, uncovered in Malapa, South Africa in 2008, reveal a mix of traits from apes, earlier Australopithecus, and Homo erectus and its descendants. The small brain (around 420 cu cm) and limb proportions match those seen in Australopithecus, however there are also modern features, such as enlargement of the frontal lobes, a wider pelvis, and human-like hands. It is possible that A. sediba is an ancestor of Homo erectus, and thus of us.
More to the point is that the1.98 million-year-old fossils force a rethink about how crucial traits are ordered in our evolution. An increase in brain size has always been considered a critical driver of traits such as changes in brain structure and the pelvis. But here we have a wider pelvis, a flatter, more human face, and a skull bump in the vicinity of Broca’s area, together with a brain no larger than a chimpanzee’s. This suggests not only that the pelvis widened purely because of a shift to bipedalism, not because of the demands of larger-brained babies, but that the increase in brain size may have occurred later in our evolution than we thought.
Additionally, the changes in the thumb are usually associated with tool-making, but the fingers are curved, suitable for tree-climbers. Although the heel bone in the foot seems primitive, angle of the front suggests an arched foot for walking on the ground, and there is a large attachment for an Achilles tendon as in modern humans.
The fossils are particularly exciting because the A. sediba skeletons are nearly complete, giving us the most complete hominid skeletons we have until we get up to the Neanderthals — including the earliest, most complete fossil hominin hand post-dating the appearance of stone tools (2.6 million years ago). The hand of A. sediba is more suited to tool-making than the 1.75 million-year-old hand belonging to Homo habilis, who were given the name “handy man”. Homo habilis has been considered to be a precursor of Homo erectus, and the South African australopithecines have been regarded as side-branches in the hominid tree. These fossils mean this view needs to be reconsidered.
The other possibility is that parallel evolution was going on, with different hominin species exploring similar traits.
September 5, 2011
Human ancestors interbred with related species
Genetic analysis points to our ancestors having bred with other hominid species. It’s been discovered that some interbreeding took place between Neanderthals and Homo sapiens in Europe between 80 and 30,000 years ago. Now a study of the DNA from two African hunter-gatherer groups, the Biaka Pygmies and the San, and a West African agricultural population known as the Mandenka, suggests that roughly 2% of their genetic material came from another hominid species some 35,000 years ago. That as yet unidentified species is estimated to have diverged from the Homo sapiens line around 700,000 years ago.
The hypothesis requires a larger data-set to be convincing, but it’s certainly intriguing.
August 31, 2011
Stone tools shed light on early human migrations
The discovery of stone axes in the same sediment layer as cruder tools indicates that hominins with differing tool-making technologies may have coexisted.
Stone axes, estimated to be around 1.76 million years old, have been found in Kenya alongside primitive tools that had already been in use for at least a million years. The hand axes are part of the Acheulian technology —thought to have been developed around 1.6 million years ago, and associated with the emergence of Homo erectus as the dominant hominin species. The more primitive tools belong to the earlier Oldowan culture.
The findings may explain why early fossil sites in Eurasia almost always reveal hominins with Oldowan toolkits, or no tools at all.
"It might have been that a single species was capable of making both kinds of tools but that factors like what raw materials were available and what tasks needed to be conducted with the tools governed which types of tools were made," says Pobiner.
August 24, 2011
DNA study deals blow to theory of European origins
Modern humans are thought to have entered Europe about 40,000 years ago. When the Ice Age came some 20,000 years ago, they retreated south, returning north when the ice melted. But a few thousand years after that, there was an influx of new settlers from Asia (Turkey), bringing with them a new farming culture.
The burning question, a matter of much debate, has been the extent to which modern Europeans are descended from these early farmers versus the indigenous hunter-gatherers.
One study focused on the Y chromosome. More than 100 million European men carry a type called R-M269. It is especially common in western Europe, with frequencies of 90% or more in Spain, Ireland and Wales. The study has found that the genetic diversity of R-M269 increases eastward, peaking in Anatolia (modern Turkey). Genetic diversity reflects how long the genes have been around in a population. The age ranges calculated support an expansion in Neolithic times (between 5,000 and 10,000 years ago).
Two recent studies have supported this finding, but another supported the idea that R-M269 has more ancient origins.
A new study, using data from more than 4,500 men from Europe and western Asia, has found no geographical trends in the diversity of R-M269. But it’s not discounting the possibility — rather, it suggests that the unreliability of some markers on the Y chromosome mean that are tools are not yet adequate for analysing this material.
But one interesting note is the finding that different subgroups of the R-M269 group are very common in different parts of Europe, consistent with expansion of these subgroups in each place.
August 3, 2011
King Tut and half of European men share DNA
Analysis of the DNA of the Egyptian Pharaoh Tutankhamun has revealed that it includes the haplogroup R1b1a2. The intriguing thing is that, while this genetic profile group is also found in 70% of British and Spanish males and 60% of French males, it is only present in less than 1% of present-day Egyptian males.
The R1b1a2 DNA haplogroup is believed to have originated in the Black Sea region some 9500 years ago and spread to Europe with the spread of agriculture in 7000BC.
July 13, 2011
New algorithm provides new insights into evolutionary exodus out of Africa
A new technique has revealed that, although the African and non-African populations might have started to differentiate as early as 100,000 to 120,000 years ago, they largely remained as one population until approximately 60,000 to 80,000 years ago. At that point, there was a dramatic drop in population (to approximately a tenth of what it had been), overlapping the period when modern human fossils and artefacts start to appear across Europe and Asia. But genetic exchange continued between the African and non-African populations for at least 20,000 years after this. One explanation could be that new emigrants from Africa continued to join the out-of-Africa populations long after the original exodus.
June 29, 2011
Finding showing human ancestor older than previously thought offers new insights into evolution
Homo erectus is widely considered a direct human ancestor; the first of our ancestors to migrate out of Africa, some 1.8 million years ago. Although Homo erectus died out in Africa and much of Asia by about 500,000 years ago, he appeared to have survived in Indonesia until about 35,000 to 50,000 years ago — meaning that they would have co-existed with Homo sapiens, who arrived about 40,000 years ago.
Such co-existence is predicted in the Out of Africa or replacement model, but not in the multiregional model.
However, more recent work on the Solo River sites has over-turned previous dating. Using three different dating techniques, it’s now concluded that the Indonesian fossils date back to at least 143,000 years ago, and perhaps as much as 550,000 years ago.
June 6, 2011
Stone fragments found in Georgia suggest Homo erectus might have evolved outside Africa.
Discoveries from the excavations at Dmanisi cast into doubt the assumption that Homo erectus evolved in Africa between 1.78 million and 1.65 million years ago, before spreading out to Europe and Asia. Stone artefacts indicative of tool-using H. erectus have been found in sediments almost 1.85 million years old. Distribution of the many artefacts also indicates long-term occupation of the site, being spread through several layers spanning the period between 1.85 million and 1.77 million years ago.
Fossil skulls dated at 1.77 million years ago had brains between 600 and 775 cubic centimetres in volume, whereas H. erectus is thought to have had an average brain size of around 900 cubic centimetres. So are these early members of Homo erectus, and did they originate in Europe rather than Africa? Or did Homo erectus venture out of Africa far earlier than thought?
May 24, 2011
Population genetics reveals shared ancestries
Analysis of publicly available genetic data from 40 populations found no sub-Saharan African genetic signatures in Northern European populations, but around 1-3% in modern southern European groups, 4-15% in Middle Eastern groups, and around 3-5% in Jewish populations.
The dates of population mixtures are consistent with documented historical events. For example, the mixing of African and southern European populations coincides with events during the Roman Empire and Arab migrations that followed. The older-mixture dates among African and Jewish populations are consistent with events in biblical times, such as the Jewish diaspora that occurred in 8th to 6th century BC.
March 25, 2011
Stone cutting tools link early humans to prehistoric India
Dating of Acheulian tools found in Tamil Nadu, in South India, suggests that Acheulian tool-making humans were present in South Asia around a million years ago or earlier, existing at the same time as other populations in southwest Asia and Africa.
March 9, 2011
Genetic analysis finds that modern humans evolved from southern Africa's Bushmen
Analysis of southern African genomes has revealed that the greatest genetic variation was seen in the Bushmen, suggesting that this population is most likely to be the original population from which all other African populations emerged. It’s estimated that these first human populations of Homo sapiens Bushmen date back about 200,000 years. The finding doesn’t necessarily contradict conclusions drawn after the recent discovery of three 160,000 year old fossils in Ethiopia, widely believed to be the likely immediate ancestors of anatomically modern humans, because no one knows where the Bushmen were located back then.
February 17, 2011
Recent "human ancestor" finds under question
Two scientists suggest that claims that three fossil species four to seven million years old, dubbed Orrorin, Sahelanthropus and Ardipithecus, belong to the human lineage, rather than that of apes, haven’t been adequately demonstrated.
February 9, 2011
Ancient teeth raise new questions about the origins of modern man
Eight teeth excavated at Qesem cave in Israel, are very similar to those of Homo sapiens found at two other sites in Israel, but are much older than those remains (which have been dated at 100,000 years). The cave was in use from about 400,000 years ago to 200,000 years ago, and the teeth were scattered through the layers, with some in the oldest layers.
If they are indeed Homo sapiens, that would put the migration out of Africa at much earlier than thought. However, they could well be Neanderthal, or other archaic human.
Whoever it was who lived in the Qesem Cave that long ago, they used fire, hunted, cut and shared meat, and mined raw materials to make flint blades.
January 27, 2011
Tools Suggest Earlier Human Exit From Africa
Discovery of stone tools dated at 125,000 years old from a site in what southern Arabia suggests that humans left Africa some 55,000 years earlier than thought. The site is near the Persian Gulf, but the gulf was a low-lying plain up until 8,000 years ago.
The finding does contradict the genetic data that indicates that all modern humans outside Africa are descended from a single, small population that left Africa less than 60,000 years ago. However, it is by no means implausible that there are people outside Africa who descend from an earlier population. On the other hand, the lack of human fossils with the tools means we can’t know whether early modern humans or Neanderthals made them.
Stone tools by unknown makers 75,000 years ago have previously been found in central India.
The findings do suggest that humans left Africa not, as has been thought, because of some technological or behavioral change, but simply because conditions allowed them to do so. Climate records indicate that between 200,000 and 130,000 years ago, a global ice age caused sea levels to fall by up to 100 metres, while the Saharan and Arabian deserts became huge inhospitable wastelands. But Arabia became much more hospitable at the same time as the sea fell to record levels, making it possible to walk across from Africa.
December 22, 2010
Denisovan species confirmed
Earlier this year, mitochondrial DNA of a 30,000 year old finger bone revealed a new hominin, named "Denisovans" after the cave in which the bone was found. Now 70% of the nuclear genome has been sequenced, confirming that this is indeed a new species. The species is more closely related to Neanderthals than ourselves, suggesting that Neandertals and Denisovans are shared a common ancestor after they split from the ancestors of modern humans.
The finger bone has also been revealed to belong to a young girl. A large molar found on the same site has also been shown to belong to this new species, but not to the same individual. The tooth is but similar to molars seen in Homo habilis and Homo erectus.
Comparison with the same segments of DNA in 53 populations of present-day humans has also revealed that the Denisovans shared certain mutations with Melanesians from Papua New Guinea and Bougainville Island, mutations not found in Neandertals or other modern populations. Melanesians appear to have inherited between 4% and 6% of their DNA from these extinct Denisovans (as well as carrying the 1-4% of Neanderthal DNA found in non-African humans).
The fact that the fossils were found in Siberia suggests the Denisovans were widespread across Asia.
So here’s a new story: an ancestral group leaving Africa between 300,000 and 400,000 years ago and quickly diverging as some went west into Europe (the Neanderthals) and others moving east (Denisovans). Later, about 70,000 to 80,000 years ago, modern humans left Africa and met (and occasionally bred with) the Neanderthals. One group of humans later met (and bred with) Denisovans.
November 24, 2010
Early Homo sapiens in China
Homo sapiens fossils from south China have been dated to more than 100,000 years ago, challenging the view that H. sapiens didn’t spread across southern Asia and to Australia until 50,000–60,000 years ago.
November 5, 2010
New statistical model moves human evolution back 3 million years
It’s been widely accepted for a long time that the human lineage diverged from that of chimpanzees around 5 to 6 million years ago. But a new statistical model, combined with fossil and DNA evidence, pushes the timeline back to 8 million years.
October 25, 2010
Modern humans emerged far earlier than previously thought
The discovery of early modern human fossil remains in the Zhirendong (Zhiren Cave) in south China that are at least 100,000 years old provides the earliest evidence for the emergence of modern humans in eastern Asia, at least 60,000 years older than the previously known modern humans in the region.
The Zhirendong fossils have a mixture of modern and archaic features that contrasts with earlier modern humans in east Africa and southwest Asia.
April 22, 2010
Out of Africa dating
New genetic analysis (resequencing of 20 independent noncoding regions in the genome in 213 individuals from different continental populations) supports a model in which modern humans left Africa through a single major dispersal event occurring around 60,000 years ago, corresponding to a drastic reduction of about 5 times the effective population size of the ancestral African population of some 13,800 individuals. The ancestors of modern Europeans and East Asians diverged much later, around 22,500 years ago.
Open access article at http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0010284
January 21, 2010
Early Homo sapiens’ small population
Humans have less genetic variation than other primates. Various "bottlenecks" — events in which a significant proportion of the population is killed or prevented from reproducing — have been suggested to explain this. For example, only some 15,000 humans are thought to have survived the nuclear winter that followed the eruption of the Toba super-volcano in Indonesia around 70,000 years ago.
Now a new genetic analysis points to a similar catastrophic event around a million years ago. The analysis uses specific elements in the genome that hark back to ancient times. Using these, it is estimated that the effective population size of human ancestors living before 1.2 million years ago was 18,500, and it is very unlikely that it was larger than 26,000.
This is unusually small for a species with such a wide distribution (and smaller than the present-day populations of gorillas and chimpanzees). Moreover, they apparently remained an endangered species for a million years.
April 6, 2010
New species of early hominid found
The Malapa cave systems, in the Sterkfontein area near Johannesburg, are a UNESCO world heritage site. An almost complete fossilized Australopithecus skeleton was discovered there in 1994. Now two partial skeletons of a new Australopithecus species, dated to between 1.95 and 1.78 million years ago, have been found there. The skeletons belonged to an adult female and a juvenile male. Another two have been found since the initial report.
The mix of Australopithecus and Homo features seen in these hominids imply that the transition from earlier hominids to the Homo genus occurred in very slow stages. The species has been named Australopithecus sediba.
The species may be an ancestor for the Homo genus, or a sister group to a close ancestor that persisted for some time after the first appearance of Homo. The Homo genus is thought by many to have evolved from Australopithecus a little more than two million years ago (the oldest Homo specimen has been dated at 2.3 million years ago), with Homo habilis representing the start of the Homo genus. However the evidence for Homo habilis is sketchy, and some suggest the genus evolved from the Kenyanthropus genus.
Kenyanthropus platyops was discovered in 2001.
March 24, 2010
Fossil finger points to new human species
New techniques for extracting mitochondrial DNA from ancient samples has enabled a fragment of bone found in 2008 in Denisova Cave in the Altai Mountains, dated to between 48,000 and 30,000 years ago, to be revealed as belonging to a new hominin.
The sample was compared to 54 modern humans, a 30,000 early modern human from Russia, 6 Neanderthals, a bonobo and a chimpanzee. The fragment's sequence differed significantly from modern human sequences, by almost twice as much as the Neanderthal differed from humans' — suggesting that it diverged from a common ancestor well before Neanderthals and modern humans did -- about one million years ago.
This may indicate a migration out of Africa after Homo erectus (about 1.9 million years ago) and before Neanderthals (between 300,000 and 500,000 years ago).
Denisova Cave is a rich source of Neanderthal artefacts.
January 8, 2010
Hominids Went Out of Africa on Rafts
Large numbers of stone hand-axes found in several places in southwestern Crete have been dated to at least 130,000 years ago and closely resemble hand axes fashioned in Africa about 800,000 years ago by Homo erectus. The axes were made from a local quartz.
Until now, the oldest known human settlements on Crete dated to around 9,000 years ago.
The idea that Homo erectus were capable of crossing the sea has already been suggested (but not widely accepted) in connection with Indonesia. Neanderthals, too, it’s been suggested, crossed the Strait of Gibraltar.
October 1, 2009
Fossil Ardi reveals the first steps of the human race
In what’s been widely touted as the most important find in human evolution in the past century, the oldest partial skeleton from a human ancestor that has ever been found shows a female who could walk upright but was still a skilled tree-climber. The fossil, found in northern Ethiopia, has been categorized as belonging to a new species — Ardipithecus ramidus — and has been nicknamed Ardi. She was about the size of a chimpanzee: around 4 feet tall (1.2m), weighing in just under 8 stone (50kg), and with a similar-sized brain. Her very long arms and fingers, and opposable toes, are presumed to have helped her move through the forest canopy. Her pelvis however, shows that she walked upright when on the ground. Her teeth indicate a diet of fruit, leaves, and small mammals. The small size of incisors and canines in both male and female Ardipithecus (other remains were found with Ardi; she was simply the most complete) reveal that the enlarged incisors and canines found in modern apes developed later.
September 8, 2009
Fossil find in Georgia challenges theories on early humans
Excavations at Dmanisi in Georgia have uncovered the earliest human remains to be discovered outside Africa: five early Homo erectus skeletons that date back to 1.8 million years ago. The remains were found with stone tools and animal bones with cut marks, and suggest a species that were about 1.5 meters tall, with brains a bit more than half our size.
April 30, 2009
Geneticists publish largest-ever study on African genetics revealing origins, migration
In the largest-ever study of African genetic data, involving more than four million genotypes, from 121 African populations and four African American populations, the ancestral origin of humans has been placed in southern Africa, near the South Africa-Namibian border, and the exit point of modern humans out of Africa near the middle of the Red Sea in East Africa.
February 27, 2009
Earliest human footprints found in Kenya
Footprints, dated to between 1.51 million and 1.53 million years ago, have been found in sedimentary rock in Kenya. The prints give evidence of a modern upright stride, and tall individuals (around 5ft 9in). They were probably made by Homo ergaster or Homo erectus, and are the earliest evidence we have of modern upright walking. The only older footprints by human ancestors are from around 3.6 million years ago, in Tanzania, which show an upright posture but a more ape-like foot (with a shallower arch and more divergent big toe). Those footprints were attributed to Australopithecus afarensis.
July 7, 2008
The Migration History of Humans: DNA Study Traces Human Origins Across the Continents
Good article in Scientific American about the genetic research that helps us trace the movement of ancient humans across the globe
July 2, 2008
Newcomer In Early Eurafrican Population?
A complete mandible of Homo erectus was discovered in Casablanca; the oldest human fossil uncovered from scientific excavations in Morocco. It was found among teeth, one of which was dated to 500,000 BC. Its morphology differs from the three mandibles dated to 700,000 B.C. that were found in Algeria and used to define Homo mauritanicus (the North African variety of Homo erectus).
April 3, 2007
China's Earliest Modern Human
A skeleton recovered in 2003 from the Tianyuan Cave, Zhoukoudian, near Beijing City, has been dated to 42,000 to 38,500 years ago, making it the oldest securely dated modern human skeleton in China and one of the oldest modern human fossils in eastern Eurasia. The specimen is basically a modern human, but it does have a few archaic characteristics, particularly in the teeth and hand bone.
The discovery casts further doubt on the longstanding "Out of Africa" theory which holds that when modern Homo sapiens spread eastwards from sub-Saharan Africa to Eurasia about 65,000 to 25,000 years ago, replacing the native late archaic humans. This fossil is evidence that these modern humans interbred with local archaic humans as they spread.
March 16, 2007
Tooth Decay Analysis Supports 'Out Of Africa' Theory Of Human Evolution
Streptoccocus mutans, a bacterium associated with dental caries, has evolved alongside Homo sapiens. Samples that include over 60 strains of the bacteria collected from Chinese and Japanese, Africans, African-Americans and Hispanics in the United States, Caucasians in the United States, Sweden, and Australia, and Amazon Indians in Brazil and Guyana, show a family tree that dates back to a single common ancestor who lived in Africa between 100,000 and 200,000 years ago.
The bacterial family tree supports a human tree rooted in Africa, with its main branch extending to Asia, and a second branch extending from Asia back to Europe, indicating the migration of a small group of Asians who founded at least one group of modern-day Caucasians.
March 13, 2007
Fossil shows human growth at least 160,000 years ago
New technology has revealed that the Moroccan fossil child dated at around 160,000 years ago and thought to be one of the earliest representatives of Homo sapiens, showed an equivalent degree of tooth development to living human children at the same age (almost 8 years old).
532 different strains of Helicobacter pylori, bacteria that cause ulcers and stomach cancer, have been collected from 51 ethnic groups. The relative genetic diversity seen in these bacteria that have followed us around the world supports the view that we originated in east Africa, and dates our exodus from Africa to about 58,000 years ago.
January 15, 2007
Putting a face on the earliest modern Europeans
A 35,000-year-old skull discovered in western Romania — the earliest largely complete example of an early modern human skull known from Europe — shows that the earliest modern humans in Europe were not completely like us.
Its combination of modern and archaic features can be used to reinforce arguments for some degree of mixture of Neandertals and modern humans. In addition to its large face and retreating forehead, it has the largest cheek teeth so far known for an otherwise anatomically modern human.
January 11, 2007
The Hofmeyr skull is adding to our knowledge of early human migration.
A fossil skull found in South Africa in 1952 that could not be dated at the time has now been dated using new techniques. It dates to about 36,000 years ago. The skull resembles that of modern humans who lived in Europe and Asia about 36,000 years ago more than fossils of Africans or Europeans from the past 10,000 years, suggesting that the humans who left Africa descend from a group in sub-Saharan Africa.
Artefacts support theory man came from Africa
A comparison of African and Indian artefacts — ostrich eggshell beads, arrow- or spearheads and barbs, and a criss-cross art style — has revealed that they are virtually identical.
Most of the African finds date from between 70,000 and 50,000 years ago, while the earliest Indian artefacts discovered so far are just 35,000 years old (although these dates may be pushed back).
The finding adds more support to the view that there was one migration from Africa outwards. Until now, archaeologists felt that the tools found in Australia were so different from those found in Europe that they must have been carried by a separate dispersal, but now they think that the Australian artefacts could be a simplified version of those found elsewhere.
February 25, 2006
Big Stone Age woman reflects cold adaptation
A 260,000-year-old partial skeleton found in northwestern China represents our largest known female ancestor. Known as the Jinniushan specimen, she is estimated at 5 feet, 5-1/2 inches tall, and 173 pounds in weight. She’s identified as belonging to the Homo genus, but her species is uncertain. Researchers suggest her size reflects membership in a cold-adapted population, with large, broad bodies with short limbs (as seen in near-polar populations today).
The fossils are consistent with the theory that our lineage peaked in body size and showed substantial brain growth between 1 million and 200,000 years ago.
April 6, 2005
New fossils support the position of Sahelanthropus tchadensis as a hominid that lived shortly after hominids diverged from chimpanzee ancestors, between 6 million and 7 million years ago. However, more discoveries are needed to decide whether Sahelanthropus represents a separate genus or belongs to a previously identified group of nearly 6-million-year-old African hominids dubbed Ardipithecus.
February 16, 2005
The oldest Homo sapiens
Fossils found in Ethiopia push the birth of our species, Homo sapiens, to some 195,000 years ago. The date is consistent with that suggested by genetic studies. The anatomically modern skull was found with a less modern one, dated within a few hundred years of each other.
January 16, 2005
Genes found in Europeans support species interbreeding
Genetic study of Icelanders has revealed a stretch of DNA (chromosome 17q21.31) that exists in two forms in the Icelandic population. In some Icelanders, this sequence is flipped. Women carrying the inverted sequence tend to have slightly more children, and it is found much more often in women over 95 and in men over 90, suggesting that it confers both fertility and longevity benefits.
The inversion was found to be rare in Africans, almost absent in Asians, but present in 20% of Europeans, as in Iceland.
Although it appears that something in the European environment in the last 10,000 years has made the mutation more desirable, its origin is ancient. The standard and flipped version last shared a common ancestor three million years ago.
It is highly unusual for two different versions of a gene to endure for so long. It may be that the two versions confer different advantages. Alternatively, it may be that the flipped version was carried in a different human lineage, entering our lineage during interbreeding in more recent times. Supporting this idea, the flipped version carries far fewer mutations than the standard version.
November 18, 2004
Ancient ape gives clue to family origins
Fossils from Spain, 13 million years old, are thought to reveal the most recent common ancestor of gorillas, chimpanzees, orangutans and humans. The species has been christened Pierolapithecus catalaunicus. The male, estimated at about the size of a female chimpanzee, shows a mixture of typical 'apelike' features alongside more primitive 'monkey' characteristics.
June 11, 2003
Human Origins from Afar
The Afar Depression in the Great Rift Valley has offered a wealth of hominid fossils over the years. In 1997, fossils categorized as Homo sapiens idaltu — the Herto people — were found. Dated at 156,000 years ago, these were then the earliest, well-dated “modern” fossils. The three skulls found also appeared to have been separated from their bodies and manipulated with stone tools, suggesting some sort of mortuary practice (cannibalism would have left much less controlled damage). Polishing also suggested that that the skulls were handled repeatedly. The dating of these fossils is of particular interest, because it is the time period that “Mitochondrial Eve” also lived.
A million-year old Homo erectus skull was also found nearby. The skull is remarkably similar to H. erectus fossils from Java, China, and Europe.
The Herto were given a subspecies name (idaltu means “elder” in the local language) because of several significant differences in the skull: larger than modern Homo sapiens, with a longer braincase and more pronounced brow ridges. These differences fit nicely between some older hominid fossils, such as Homo heidelbergensis, and modern humans.
March 5, 2004
Ancient teeth point to earliest humans
The discovery of more fossil teeth in Ethiopia have caused researchers to reclassify the remains of at least five individual hominids from between 5.2 and 5.8 million years ago. At the time they were classified as Ardipithecus ramidus kadabba ("root-man ancestor") on the assumption that it was a subspecies of Ardipithecus ramidus. They have now been reclassified as a new species: Ardipithecus kadabba. This species may be the first on the human branch after the split between the lines that would lead to chimpanzees on one branch, and humans on the other. They appear to have lived in a wooded, wet environment, and from the toe bone, it appears they walked on two feet when on the ground.
July 4, 2002
Fossil Skull Discovered In Eurasia Challenges Early-Human Theories
A fossil skull found in Georgia and dated at 1.75 million years, is quite ape-like, with a small brain, thin brow and large canine teeth. The find challenges a long-held assumption that leaving Africa would have required a big brain. Other fossils found at the same site reveal a huge range in size, although they are thought to all belong to the same species. The fossils were also found with hundreds of animal bones and thousands of simple stone tools.
March 20, 2002
Fossil indicates Homo erectus, was single, widespread species 1 million years ago
A million-year-old Homo erectus skull found in Ethiopia has now been carefully assembled and analysed, and scientists say it is clearly exactly the same as those found in Europe and Asia, demonstrating that Homo erectus was a single species spread over the world, not two separate species, as some have argued.
It is suggested that the onset of the Ice Ages about 950,000 years ago split the Homo erectus populations and led to their divergent evolution, with the African population giving rise to modern Homo sapiens, and the European branch perhaps becoming the Neandertals, and the Asian population dying out. Homo erectus first appeared about 1.8 million years ago and disappeared some 400,000 years ago. The largest number of Homo erectus specimens are from Asia, including the first specimen ("Java Man").
September 14, 2001
Oldest Hominid Fossils in Southern Africa Found
The oldest known hominid fossils yet found in southern Africa, dating back 3.5 million years, have been found at the world-renowned Sterkfontein Caves, north of Johannesburg.
November 9, 2001
Archaeological Discovery in N. China Challenges Theory on Origin of Man
Excavations in north China's Hebei Province have unearthed more than 800 stone tools and animal skeletons in a stratum dating back around 2 million years.