Analysis of nuclear DNA from Sima de los Huesos hominins provides evidence of their relationship to Neandertals
Previous analyses of the hominins from Sima de los Huesos in 2013 showed that their maternally inherited mitochondrial DNA was distantly related to Denisovans, extinct relatives of Neandertals in Asia. This was unexpected since their skeletal remains carry Neandertal-derived features. Researchers of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, have since worked on sequencing nuclear DNA from fossils from the cave, a challenging task as the extremely old DNA is degraded to very short fragments. The results now show that the Sima de los Huesos hominins were indeed early Neandertals. Neandertals may have acquired different mitochondrial genomes later, perhaps as the result of gene flow from Africa.
Until now it has been unclear how the 28 400,000-year-old individuals found at the Sima de los Huesos (“pit of bones”) site in Northern Spain were related to Neandertals and Denisovans who lived until about 40,000 years ago. A previous report based on analyses of mitochondrial DNA from one of the specimens suggested a distant relationship to Denisovans, which is in contrast to other archaeological evidence, including morphological features that the Sima de los Huesos hominins shared with Neandertals.
“Sima de los Huesos is currently the only non-permafrost site that allow us to study DNA sequences from the Middle Pleistocene, the time period preceding 125,000 years ago”, says Matthias Meyer of the Max Planck Institute for Evolutionary Anthropology, lead author of an article that was published in Nature today. “The recovery of a small part of the nuclear genome from the Sima de los Huesos hominins is not just the result of our continuous efforts in pushing for more sensitive sample isolation and genome sequencing technologies”, Meyer adds. “This work would have been much more difficult without the special care that was taken during excavation”.
Residents of the remote equatorial islands of Melanesia share fragments of genetic code with two extinct human species. That’s the key finding of a new study published March 17 in the journal Science.
An international team contributed to the research, which compared the DNA sequences of 35 modern people living on islands off the coast of New Guinea with DNA drawn from two early human species: Denisovans, whose remains were found in Siberia, and Neandertals, first discovered in Germany.
“Substantial amounts of Neandertal and Denisovan DNA can now be robustly identified in the genomes of present-day Melanesians, allowing new insights into human evolutionary history,” they wrote. “As genome-scale data from worldwide populations continues to accumulate, a nearly complete catalog of surviving archaic lineages may soon be within reach.”
D. Andrew Merriwether, a molecular anthropologist at Binghamton University, collected the modern-day blood samples used in the study about 15 years ago in Melanesia. This is the first time full genomes from those samples have been sequenced.
“I’m surprised that these Neandertal and Denisovan genomes made it out to this remote place,” he said. “We know people have been there for at least 48,000 years because we find human remains that go back that far, but no one has ever been able to connect them to any other place. When you compare most of their genome sequences, they don’t cluster with any other group. They’ve been there and been isolated for a very, very long time.”
Earlier studies have revealed some genetic overlap (about 2 percent) between Neandertals and non-African populations and little or no Neandertal and Denisovan ancestry among Africans. This new research suggests Neandertals and modern human ancestors intersected at least three times. It also found an overlap of between 1.9 and 3.4 percent in the genetic codes of Denisovans and modern-day Melanesians.
Skepticism about the new findings is entirely appropriate, said Merriwether, who specializes in reconstructing the past using samples from contemporary populations and ancient DNA from the archaeological record.
The saint’s legend speaks of a king who died a dramatic death in battle outside the church where he had just celebrated mass. But what can modern science tell us about his remains? A joint research project headed by Uppsala University now reveals more of the health condition of the medieval king Erik, what he looked like, where he lived and what the circumstances of his death were.
No contemporary sources mention Erik Jedvardsson, the Swedish king who was later sainted. The only account of his life is the saint’s legend, in its preserved form written in the 1290’s. Such legends are often unreliable. The Erik legend is, however, based on an older legend which has been lost, and this longer legend may have been much older.
The preserved legend says that Erik was chosen to be king, ruled fairly, was a devoted Christian, led a crusade against Finland, and supported the Church. He was killed in 1160, in his tenth year of rule, by a Danish claimant to the throne. His remains have rested in a reliquary since 1257.
Tiny Island Deer in Panama Was Hunted to Extinction Thousands of Years Ago
As polar ice caps melted at the end of the last Ice Age about 8,500 years ago, the global sea level rose and Panama’s Pearl Islands were isolated from the mainland. A new archaeological study by a team including a Smithsonian scientist shows that several thousand years later pre-Columbian colonists hunted a dwarf deer to extinction on an island called Pedro González.
The settlers arrived on the 14-hectare island by sea 6,200 years ago and stayed for a maximum of eight centuries, farming maize and roots, fishing, gathering palm fruits and shellfish and hunting deer, opossums, agoutis, iguanas and large snakes—the major predators.
Pioneering Rutgers scientist helps reconstruct an ancient East African landscape where human ancestors lived 1.8 million years ago
Scientists have pieced together an early human habitat for the first time, and life was no picnic 1.8 million years ago.
Our human ancestors, who looked like a cross between apes and modern humans, had access to food, water and shady shelter at a site in Olduvai Gorge, Tanzania. They even had lots of stone tools with sharp edges, said Gail M. Ashley, a professor in the Rutgers Department of Earth and Planetary Sciences in the School of Arts and Sciences.
But “it was tough living,” she said. “It was a very stressful life because they were in continual competition with carnivores for their food.”
It was a very stressful life because they were in continual competition with carnivores for their food.
Gail M. Ashley, professor in the Rutgers Department of Earth and Planetary Sciences
In a middle-class tomb just east of the Nile River in what was Upper Nubia, a woman offers a glimpse of how two met civilizations met, mingled and a new pharaonic dynasty arose. Her tomb was Egyptian, but she was buried in the Nubian style — placed in a flexed position on her side and resting on a bed. Around her neck she wore amulets of the Egyptian god Bes, the protector of households.
Found in 2015, the Nubian woman is, according to Stuart Tyson Smith, a professor of archaeology and chair of the Department of Anthropology at UC Santa Barbara, a prime example of “cultural entanglement,” the process by which colonizing powers and indigenous people influence one another and change over time.
In a paper accepted for publishing in American Anthropologist, Michele Buzon of Purdue University and Smith explore cultural identity and transformation in the ancient village of Tombos in what is now northern Sudan. “Entanglement and the Formation of Ancient Nubian Napatan State” details the findings from Smith and Buzon’s excavations of cemeteries in Tombos, which became an important colonial hub after the Egyptians conquered Nubia around 1500 BCE.
“You get this really interesting entangled culture blending different elements in really different ways, but also there seems to be a lot of individual choice involved,” Smith explained. “It’s not just a matter of the two cultures mash up and then you get this new hybrid thing that’s consistent. There seems to be a lot of individual choice — whether or not you want a Nubian bed and/or an Egyptian coffin and/or to be wrapped like a mummy or whether or not you want an Egyptian-style amulet and/or Nubian ivory jewelry.”
The artwork on the tiny fragile pendant, uncovered by a research team from the Universities of York, Manchester and Chester, is the earliest known Mesolithic art in Britain. Crafted from a single piece of shale, the subtriangular three-millimetre thick artefact measuring 31mm by 35mm contains a series of lines which archaeologists believe may represent a tree, a map, a leaf or even tally marks.
Engraved motifs on Mesolithic pendants are extremely rare and no other engraved pendants made of shale are known in Europe.
When archaeologists uncovered the pendant last year, the lines on the surface were barely visible. The research team used a range of digital microscopy techniques to generate high resolution images to help determine the style and order of engraving. They also carried out scientific analysis to try to establish if the pendant had been strung or worn and whether pigments had been used to make the lines more prominent.
The research, which is part of a five-year project supported by the European Research Council, is published in Internet Archaeology http://dx.doi.org/10.11141/ia.40.8. The research is also supported by Historic England and the Vale of Pickering Research Trust. The pendant is to be showcased to the public for the first time in a display at the Yorkshire Museum in York on 27 February until 5 May.
A new way of examining the teeth of children who lived between the 11th and 15th centuries without damaging them has been discovered.
Medieval children’s milk teeth
By using 3D microscopic imaging, researchers from the universities of Kent (UK) and Indianapolis (USA) have been able to safely reconstruct the diet of children who would have lived next door to Canterbury Cathedral when Chaucer was writing his famous Tales.
The 3D technology – known as dental microwear texture analysis – involved measuring microscopic changes in the surface topography of the teeth.This is the first time that this technology has been applied to children’s teeth.
By using this technology Kent’s Dr Patrick Mahoney, biological anthropologist, (School of Anthropology and Conservation), and colleagues, who included a historian, were able to learn more about how diet varied among children from poor and wealthy families in medieval Canterbury.
Dietary reconstructions from ancient teeth are often destructive, but this technology offers a new way to access this information without damaging fragile teeth.
Dr Mahoney is a leading expert on dental development of modern human children. He expects that applications of this technique will pioneer a new era in anthropological studies, opening up the dietary secrets of ancient children, and our fossil ancestors.
The findings, which were funded by a British Academy-Leverhulme Trust research grant, were presented in the February edition of Journal of Archaeological Science.
(Text & Images’ Source: article by Sandy Fleming, University of Kent)
Reintroduction of genetically distinct subspecies has led to hybridization in an endangered wild population
As their natural habitats continue to be destroyed, increasing numbers of displaced endangered mammals are taken to sanctuaries and rehabilitation centres worldwide. The ultimate goal of these centres is often reintroduction: to return these animals to wild populations. In a new study published today in Scientific Reports, however, Graham L Banes and Linda Vigilant of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, caution that such reintroductions can act as a form of genetic translocation. By using genetic analysis to assess a subset of historical reintroductions into Tanjung Puting National Park, Indonesia, they found that orang-utans from a non-native and genetically distinct subspecies were unwittingly released and have since hybridized with the Park’s wild population. As orang-utan subspecies are thought to have diverged around 176,000 years ago, with marked differentiation over the last 80,000 years, the researchers highlight the potential for negative effects on the viability of populations already under threat.
When Biruté Galdikas and Rod Brindamour began their pioneering orang-utan rehabilitation efforts at Camp Leakey in Tanjung Puting National Park, Central Kalimantan, all orang-utans were considered a single species. Over 14 years, from 1971 to 1985, they released at least 90 orphaned and displaced apes into the surrounding wild population. Advances in morphological and genetic studies have since revealed two species of orang-utan, however, on the islands of Borneo and Sumatra. The Bornean orang-utan is further subdivided into three distinct, geographically and reproductively isolated subspecies, which last shared a common ancestor in the Pleistocene and have differentiated substantially over tens of thousands of years.
Hybridization in the national park
Using genetic analyses and 44 years of data from Camp Leakey, Banes and Vigilant worked with Galdikas to determine the minimum extent to which she released non-native subspecies into the National Park. They found that Rani and Siswoyo, two females that Galdikas rescued from the pet trade, had originally been captured from northern West Kalimantan or Sarawak, and thus were of the non-local subspecies Pongo pygmaeus pygmaeus. Since their release into Tanjung Puting National Park, the pair have inter-bred prolifically with males of the local subspecies, Pongo pygmaeus wurmbii, producing at least 22 hybridized descendants to date. These offspring inherited a ‘cocktail’ of genes that could not normally occur in the wild.
Inter-breeding animals from two genetically distinct populations can sometimes lead to ‘hybrid vigor’, in which offspring reap the benefits of their parents’ individual qualities. This could explain how Rani came to found the biggest family of any female reintroduced at Camp Leakey, with at least 14 descendants over three generations. Though two died in infancy, the remainder are presumed to be alive and none are known to have required any veterinary interventions. However, “offspring born to parents from two genetically distinct populations, which have not been in genetic contact for significant periods of time, have also been shown to suffer poor health and reproductive success in a range of different species,” said Vigilant.
Strikingly, in stark contrast to Rani, Siswoyo had fewer surviving, healthy offspring than any other female at the site, which might be linked to such ‘outbreeding depression’. Her descendants are comparatively few, with only five first-generation and three second-generation offspring. Two of her offspring died in infancy, while infection following the latter pregnancy resulted in Siswoyo’s own death ten days after the birth. Her only daughter, Siswi, produced a stillborn offspring, a daughter that died in infancy, and a son that often needed medical interventions. Siswi herself has frequently required veterinary care, including major surgery to treat a perforated intestine.
Reintroduction only after genetic testing
“There is no definitive evidence of outbreeding depression among Bornean orang-utans,” says Banes, “but our findings are enough to cause serious alarm.” More than 1,500 orphaned and displaced orang-utans are currently awaiting release from centres on Borneo and Sumatra, which missed a deadline set forth by the Indonesian government to reintroduce all their orang-utans by the end of 2015. As their intake of displaced orang-utans increases, and as suitable habitat for reintroductions declines, there have been suggestions that they hybridize Bornean orang-utan subspecies – either in isolated, ‘mixed’ populations, or within existing wild populations.
Banes and Vigilant advocate genetic testing prior to all reintroductions of displaced animals, in accordance with established international guidelines. While their findings and recommendations apply to a broad range of endangered mammals, Banes is especially adamant that Bornean orang-utan subspecies be kept apart. “They might look roughly the same, but these orang-utans from different subpopulations haven’t shared a common ancestor for tens of thousands of years. It may be that inter-breeding them has no ill effects at all, but what if it does? Suddenly, for the sake of short-term welfare, we’ve compromised the viability of wild populations – and we can never take that back.”
Graham L. Banes, Biruté M. F. Galdikas and Linda Vigilant, Reintroduction of confiscated and displaced mammals risks outbreeding and introgression in natural populations, as evidenced by orang-utans of divergent subspecies, Scientific Reports, 25 February 2016, DOI: 10.1038/srep22026
(Text & Images’ Source: Max Planck Institute for Evolutionary Anthropology)
Researchers find evolution of human teeth to be much simpler than previously thought, and can predict the sizes of teeth missing from hominin fossils
A new study led by evolutionary biologist Alistair Evans of Monash University in Australia, took a fresh look at the teeth of humans and fossil hominins. The research confirms that molars, including ‘wisdom teeth’ do follow the sizes predicted by what is called ‘the inhibitory cascade’ – a rule that shows how the size of one tooth affects the size of the tooth next to it. This is important because it indicates that human evolution was a lot simpler than scientists had previously thought. The international team included researchers of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany: The analysis of digital data on fossil hominins generated by the Department of Human Evolution made this large-scale study on dental development possible.
Alistair Evans explains how our fascination with where we come from, and what our fossil ancestors were like, has fuelled our search for new fossils and how we can interpret them. “Teeth can tell us a lot about the lives of our ancestors, and how they evolved over the last 7 million years. What makes modern humans different from our fossil relatives? Palaeontologists have worked for decades to interpret these fossils, and looked for new ways to extract more information from teeth,” says Evans.
He then discusses how this new research has challenged the accepted view that there was a lot of variation in how teeth evolved in our closest relatives. “Our new study shows that the pattern is a lot simpler than we first thought – human evolution was much more limited,” says Evans. He led an international team of anthropologists and developmental biologists from Finland, USA, UK and Germany, using a new extensive database on fossil hominins and modern humans collected over several decades, as well as high resolution 3D imaging to see inside the fossil teeth.
The team then took the research a step further by applying the findings to two main groups of hominins: the species in the genus Homo (like us and Neanderthals), and australopiths, including specimens like Lucy, the famous fossil hominin from Africa. Evans explains that while it was discovered that both groups follow the inhibitory cascade, they do so slightly differently. “There seems to be a key difference between the two groups of hominins – perhaps one of the things that define our genus, Homo,” says Evans.
“What’s really exciting is that we can then use this inhibitory cascade rule to help us predict the size of missing fossil teeth. Sometimes we find only a few teeth in a fossil. With our new insight, we can reliably estimate how big the missing teeth were. The early hominin Ardipithecus is a good example – the second milk molar has never been found, but we can now predict how big it was,” says Evans, who is also a research associate at Museum Victoria.
The findings of the study will be very useful in interpreting new hominin fossil finds, and looking at what the real drivers of human evolution were. As well as shedding new light on our evolutionary past, this simple rule provides clues about how we may evolve into the future.
Alistair R. Evans, E. Susanne Daly, Kierstin K. Catlett, Kathleen S. Paul, Stephen J. King, Matthew M. Skinner, Hans P. Nesse, Jean-Jacques Hublin, Grant C. Townsend, Gary T. Schwartz and Jukka Jernvall, A simple rule governs the evolution and development of hominin tooth size, Nature, 25 February 2016
(Text & Images’ Source: Max Planck Institute for Evolutionary Anthropology)