Ancient roman DNA reveals genetic crossroads of Europe and Mediterranean

All roads may lead to Rome, and in ancient times, a great many European genetic lineages did too, according to a new study. Its results, perhaps the most detailed analysis of changing genetic variation patterns in the region to date, reveal a dynamic population history from the Mesolithic (~10,000 BCE) into modern times, and spanning the rise and fall of the Roman Empire. At its height, the ancient Roman Empire sprawled across three continents, encompassing the entirety of the Mediterranean and the lives of tens of millions across Europe, the Near East and North Africa. The size of the city at its center, Rome - the first to reach more than one million residents in the ancient world - would remain unrivaled in Europe until the dawn of the industrial revolution nearly 1,500 years later. Even long before the rise of Imperial Rome, the region was an important cultural crossroads between Europe and the Mediterranean. However, while Rome and central Italy's antiquity is well-documented in a rich archaeological and historical record, little is known about the region's genetic history.

Margaret Antonio and colleagues present a new genetic record, built from genome data of 127 ancient individuals from 29 archaeological sites in and around Rome, spanning nearly 12,000 years of Roman prehistory and history. Antonio et al. revealed two major prehistoric ancestry shifts - one occurring as Neolithic farmers replaced Mesolithic hunter-gathers roughly 7,000 years ago, and another during the Bronze age likely coinciding with increased trade and interaction with populations from across the Mediterranean. The results suggest that by Rome's founding, the genetics of ancient central Italy were much the same as that seen in modern populations. However, throughout the historic period (the past 3,000 years), genetic ancestry was greatly diverse, with genetic contributions from individuals from across the Near East, Europe and North Africa, and changes largely reflected major Roman historical events, the authors say.

Stanford scientists link Neanderthal extinction to human diseases

Stanford University -- School of Humanities and Sciences

IMAGE: This is an illustration of modern humans overcoming disease burden before Neanderthals. view more 

Credit: Vivian Chen Wong

Growing up in Israel, Gili Greenbaum would give tours of local caves once inhabited by Neanderthals and wonder along with others why our distant cousins abruptly disappeared about 40,000 years ago. Now a scientist at Stanford, Greenbaum thinks he has an answer.
In a new study published in the journal Nature Communications, Greenbaum and his colleagues propose that complex disease transmission patterns can explain not only how modern humans were able to wipe out Neanderthals in Europe and Asia in just a few thousand years but also, perhaps more puzzling, why the end didn't come sooner.
"Our research suggests that diseases may have played a more important role in the extinction of the Neanderthals than previously thought. They may even be the main reason why modern humans are now the only human group left on the planet," said Greenbaum, who is the first author of the study and a postdoctoral researcher in Stanford's Department of Biology.
The slow kill
Archeological evidence suggests that the initial encounter between Eurasian Neanderthals and an upstart new human species that recently strayed out of Africa -- our ancestors -- occurred more than 130,000 years ago in the Eastern Mediterranean in a region known as the Levant.
Yet tens of thousands of years would pass before Neanderthals began disappearing and modern humans expanded beyond the Levant. Why did it take so long?
Employing mathematical models of disease transmission and gene flow, Greenbaum and an international team of collaborators demonstrated how the unique diseases harbored by Neanderthals and modern humans could have created an invisible disease barrier that discouraged forays into enemy territory. Within this narrow contact zone, which was centered in the Levant where first contact took place, Neanderthals and modern humans coexisted in an uneasy equilibrium that lasted tens of millennia.
Ironically, what may have broken the stalemate and ultimately allowed our ancestors to supplant Neanderthals was the coming together of our two species through interbreeding. The hybrid humans born of these unions may have carried immune-related genes from both species, which would have slowly spread through modern human and Neanderthal populations.
As these protective genes spread, the disease burden or consequences of infection within the two groups gradually lifted. Eventually, a tipping point was reached when modern humans acquired enough immunity that they could venture beyond the Levant and deeper into Neanderthal territory with few health consequences.
At this point, other advantages that modern humans may have had over Neanderthals -- such as deadlier weapons or more sophisticated social structures -- could have taken on greater importance. "Once a certain threshold is crossed, disease burden no longer plays a role, and other factors can kick in," Greenbaum said.
Why us?
To understand why modern humans replaced Neanderthals and not the other way around, the researchers modeled what would happen if the suite of tropical diseases our ancestors harbored were deadlier or more numerous than those carried by Neanderthals.
"The hypothesis is that the disease burden of the tropics was larger than the disease burden in temperate regions. An asymmetry of disease burden in the contact zone might have favored modern humans, who arrived there from the tropics," said study co-author Noah Rosenberg, the Stanford Professor of Population Genetics and Society in the School of Humanities and Sciences.
According to the models, even small differences in disease burden between the two groups at the outset would grow over time, eventually giving our ancestors the edge. "It could be that by the time modern humans were almost entirely released from the added burden of Neanderthal diseases, Neanderthals were still very much vulnerable to modern human diseases," Greenbaum said. "Moreover, as modern humans expanded deeper into Eurasia, they would have encountered Neanderthal populations that did not receive any protective immune genes via hybridization."
The researchers note that the scenario they are proposing is similar to what happened when Europeans arrived in the Americas in the 15th and 16th centuries and decimated indigenous populations with their more potent diseases.
If this new theory about the Neanderthals' demise is correct, then supporting evidence might be found in the archeological record. "We predict, for example, that Neanderthal and modern human population densities in the Levant during the time period when they coexisted will be lower relative to what they were before and relative to other regions," Greenbaum said.

The genetic imprint of Palaeolithic has been detected in North African populations

IMAGE: The origin and history of the population of North Africa are different from the rest of the continent and are more similar to the demographic history of regions outside Africa. view more 

Credit: Michael Gaida, Pixabay

An international team of scientists has for the first time performed an analysis of the complete genome of the population of North Africa. They have identified a small genetic imprint of the inhabitants of the region in Palaeolithic times, thus ruling out the theory that recent migrations from other regions completely erased the genetic traces of ancient North Africans. The study was led by David Comas, principal investigator at UPF and at the Institute of Evolutionary Biology (IBE: CSIC-UPF) and it has been published in the journal Current Biology.
The field of genomics has evolved greatly in recent years. DNA sequencing is increasingly affordable and there are major projects studying genomes at population level. However, some human populations like those of North Africa have been systematically ignored. This is the first genomic study to contextualize this region of the world.
The origin and history of the population of North Africa are different from the rest of the continent and are more similar to the demographic history of regions outside Africa: the Middle East, Europe or Asia. Palaeontological remains exist that prove the existence of humans in the region more than 300,000 years ago. In any case, previous genetic studies had shown that current populations of North Africa originated as a result of a Back to Africa process, that is, recent migrations from the Middle East that populated northern Africa.
Hence, the debate that arises is one of continuity versus replacement. On the one hand, the continuity hypothesis posits that current North African populations descend from Palaeolithic groups, i.e., that such ancient humans are the ancestors of present human populations. Meanwhile, other hypotheses argue that the populations that existed in Palaeolithic times were replaced, and that the humans that currently inhabit North Africa are the result of recent migrations that arrived there as of the Neolithic.
In this study, the researchers compared genetic data from current North African individuals with data recently published on the DNA of fossil remains found at different sites in Morocco. "We see that the current populations of North Africa are the result of this replacement but we detect small traces of this continuity from Palaeolithic times, i.e., total replacement did not take place in the populations of North Africa", reveals David Comas, full professor of Biological Anthropology at the Department of Experimental and Health Sciences (DCEXS) at UPF. "We do not know whether the first settlers 300,000 years ago are their ancestors, but we do detect imprints of this continuity at least since Palaeolithic times, since 15,000 years ago or more", he adds.
"We have seen that the genetic imprint of Palaeolithic populations of North Africa is unique to the current North African populations and is decreasingly distributed from west to east in the region, inversely proportionally to the Neolithic component coming from the Middle East, which had a greater effect on the eastern region, which is geographically closer", says Gerard Serra-Vidal, first author of the article.
"Therefore, our results confirm that migrations from other regions such as Europe, the Middle East and sub-Saharan Africa to this area did not completely erase the genetic traces of the ancient North Africans", explains David Comas, head of the Human Genome Diversity research group of the IBE.
These results of the populations of North Africa are in contrast with what is known about the European continent, in whose current populations a strong Palaeolithic component is found, i.e., more continuity and less replacement than in North Africa.
Many genomic data are still missing, both of current populations and of fossil remains, to be able to establish the population history of the human species. "This is or particular concern in populations such as those of North Africa about which we have very little information compared to other populations in the world. In order to have a complete picture of human genome diversity still have to do a considerable amount of research", David Comas concludes.

How Human Population came from our ability to cooperate

Humans may owe their place as Earth's dominating species to their ability to share and cooperate with each other, according to a new study published in the Journal of Anthropological Research.
In "How There Got to Be So Many of Us: The Evolutionary Story of Population Growth and a Life History of Cooperation," Karen L. Kramer explores the deep past to discover the biological and social underpinnings that allowed humans to excel as reproducers and survivors. She argues that the human tendency to bear many children, engage in food sharing, division of labor, and cooperative childcare duties, sets us apart from our closest evolutionary counterparts, the apes.
In terms of population numbers, few species can compare to the success of humans. Though much attention on population size focuses on the past 200 years, humans were incredibly successful even before the industrial revolution, populating all of the world's environments with more than a billion people. Kramer uses her research on Maya agriculturalists of Mexico's Yucatan Peninsula and the Savanna Pumé hunter-gatherers of Venezuela to illustrate how cooperative childrearing increases the number of children that mothers can successfully raise and--in environments where beneficial--even speed up maturation and childbearing. Kramer argues that intergenerational cooperation, meaning that adults help support children, but children also share food and many other resources with their parents and other siblings, is at the center of humans' demographic success. "Together our diet and life history, coupled with an ability to cooperate, made us really good at getting food on the table, reproducing, and surviving," Kramer writes.
During her time with the Maya, Kramer constructed a demographic model that considered how much household members consume, as the family grows and matures across a mother's reproductive career, balanced against how much a mother, father, and their children contribute. She found that Maya children contributed a substantial amount of work to the family's survival, with those aged 7-14 spending on average 2 to 5 hours working each day, and children aged 15-18 spending as much as their parents, about 6.5 hours a day. Labor type varied, with younger children doing much of the childcare, older children and fathers fill in much of the day-today cost of growing and processing food and running the household. "If mothers and juveniles did not cooperate, mothers could support far fewer children over their reproductive careers," Kramer writes. "It is the strength of intergenerational cooperation that allows parents to raise more children than they would otherwise be able to on their efforts alone."
Kramer's second research population were the Savanna Pumé, hunter-gatherers in west-central Venezuela. The Savanna Pumé live in a high-mortality environment, with challenges such as seasonal undernutrition, high immunological stress, chronic intestinal parasite loads, endemic malaria, and no access to healthcare or immunization. Despite all this--or perhaps, in part, because of it--Savanna Pumé girls mature quickly and begin childbearing in their mid-teens. This pattern conforms with theoretic predictions that fast maturation optimizes fitness in a high-mortality environment. Early childbearing is also, however, associated with a higher probability of mothers losing their firstborn.
Kramer found that intergenerational cooperation mitigated these risks. "In this challenging environment, young Pumé females are buffered against seasonal fluctuations because food is shared with them, she writes. "If young Pumé mothers relied solely on their own efforts, they would have to delay childbearing until they matured as foragers and caretakers.
Humans' ability to reproduce more successfully than other great apes can be traced to differences in evolutionary strategy: humans bear more children, at a faster rate. They also provision food for juveniles, whereas other great apes stop helping children find food as soon as they have been weaned. Humans are able to shoulder the greater childcare burden through cooperation.
"Combined, these fertility parameters mean that if a natural fertility mother survives her reproductive career, she can have almost twice as many offspring as nonhuman great ape mothers," she writes. "Humans are an astonishingly successful ape."

Study reveals that humans migrated from Europe to the Levant 40,000 years ago

IMAGE: A view of Manot cave and a close up of the area where some of the teeth were found. view more 

Credit: Prof. Israel Hershkovitz/American Friends of Tel Aviv University.

Who exactly were the Aurignacians, who lived in the Levant 40,000 years ago? Researchers from Tel Aviv University, the Israel Antiquities Authority, and Ben-Gurion University now report that these culturally sophisticated yet mysterious humans migrated from Europe to the Levant some 40,000 years ago, shedding light on a significant era in the region's history.
The Aurignacian culture first appeared in Europe some 43,000 years ago and is known for having produced bone tools, artifacts, jewelry, musical instruments, and cave paintings. For years, researchers believed that modern man's entry into Europe led to the rapid decline of the Neanderthals, either through violent confrontation or wresting control of food sources. But recent genetic studies have shown that Neanderthals did not vanish. Instead, they assimilated into modern human immigrant populations. The new study adds further evidence to substantiate this theory.
Through cutting-edge dental research on six human teeth discovered at Manot Cave in the Western Galilee, Dr. Rachel Sarig of TAU's School of Dental Medicine and Dan David Center Center for Human Evolution and Biohistory Research, Sackler Faculty of Medicine in collaboration with Dr. Omry Barzilai of the Israel Antiquities Authority and colleagues in Austria and the United States, have demonstrated that Aurignacians arrived in modern-day Israel from Europe some 40,000 years ago -- and that these Aurignacians comprised Neanderthals and Homo sapiens alike.
A report on the new findings was published in the Journal of Human Evolution on October 11.
"Unlike bones, teeth are preserved well because they're made of enamel, the substance in the human body most resistant to the effects of time," Dr. Sarig explains. "The structure, shape, and topography or surface bumps of the teeth provided important genetic information. We were able to use the external and internal shape of the teeth found in the cave to associate them with typical hominin groups: Neanderthal and Homo sapiens."
The researchers performed in-depth lab tests using micro-CT scans and 3D analyses on four of the teeth. The results surprised the researchers: Two teeth showed a typical morphology for Homo sapiens; one tooth showed features characteristic of Neanderthals; the last tooth showed a combination of Neanderthal and Homo sapiens features.
This combination of Neanderthal and modern human features has, to date, been found only in European populations from the early Paleolithic period, suggesting their common origin.
"Following the migration of European populations into this region, a new culture existed in the Levant for a short time, approximately 2,000-3,000 years. It then disappeared for no apparent reason," adds Dr. Sarig. "Now we know something about their makeup."
"Until now, we hadn't found any human remains with valid dating from this period in Israel," adds Prof. Israel Hershkovitz, head of the Dan David Center, "so the group remains a mystery. This groundbreaking study contributes to the story of the population responsible for some of the world's most important cultural contributions."

Minoan treasures found on Libyan Sea island: Experts

A team excavating on the tiny island of Chrysi south of Crete for over a decade have unearthed a 3,800-year-old Bronze Age compound containing gold jewels, glass beads and the remains of bronze talents, the common unit of value of ancient Greece. © ΥΠΠΟΑ.

ATHENS (AFP).- Archaeologists in Greece have located a "major treasure" of Minoan origin in a Bronze Age settlement on a small island in the Libyan Sea, the culture ministry said Friday. A team excavating on the tiny island of Chrysi south of Crete for over a decade have unearthed a 3,800-year-old Bronze Age compound containing gold jewels, glass beads and the remains of bronze talents, the common unit of value of ancient Greece. Some of the beads are of Egyptian origin, the culture ministry said in a statement. The archaeologists also found ancient fish tanks and large amounts of porphyry -- a prized purple pigment of the ancient world derived from sea snails, and later the colour exclusively reserved for Roman emperors.

Complete report

The last Neanderthal necklace

IMAGE: This is a falange of imperial eagle with marks of court from Cave Foradada view more 

Credit: Antonio Rodríguez-Hidalgo

Eagle talons are regarded as the first elements used to make jewellery by Neanderthals, a practice which spread around Southern Europe about 120,000 and 40,000 years ago. Now, for the first time, researchers found evidence of the ornamental uses of eagle talons in the Iberian Peninsula. An article published in the cover of the journal Science Advances talks about the findings, which took place in the site of the cave Foradada in Calafell. The article was led by Antonio Rodríguez-Hidalgo, researcher at the Institute of Evolution in Africa (IDEA) and member of the research team in a project of the Prehistoric Studies and Research Seminar (SERP) of the UB.
The interest in these findings lies in the fact that it is the most modern piece of the kind so far regarding the Neanderthal period and the first one found in the Iberian Peninsula. This circumstance widens the temporary and geographical limits that were estimated for this kind of Neanderthal ornaments. This would be "the last necklace made by the Neanderthals", according to Antonio Rodríguez-Hidalgo.
"Neanderthals used eagle talons as symbolic elements, probably as necklace pendants, from the beginnings of the mid Palaeolithic", notes Antonio Rodríguez-Hidalgo. In particular, what researchers found in Cova Foradada are bone remains from Spanish Imperial Eagle (Aquila Adalberti), from more than 39,000 years ago, with some marks that show these were used to take the talons so as to make pendants. The found remains correspond to the left leg of a big eagle. By the looks of the marks, and analogy regarding remains from different prehistorical sites and ethnographic documentation, researchers determined that the animal was not manipulated for consumption but for symbolic reasons. Eagle talons are the oldest ornamental elements known in Europe, even older than seashells Homo sapiens sapiens perforated in northern Africa.
The findings belong to the châtelperronian culture, typical from the last Neanderthals that lived in Europe, and coincided with the moment when this species got in touch with Homo sapiens sapiens, from Africa -and expanding from the Middle East. Actually, Juan Ignacio Morales, researcher in the program Juan de la Cierva affiliated at SERP and signer of the article, presents this use of eagle talons as ornaments could have been a cultural transmission from the Neanderthals to modern humans, who adopted this practice after reaching Europe.
Cova Foradada covers the most meridional châtelperronian culture site in Europe. The discovery involved a change in the map of the territory where the step from Middle Palaeolithic to Upper Palaeolithic took place 40,000 years ago, and where interaction between Neanderthals and Homo sapiens sapiens probably took place. Studies in Cova Foradada started in 1997. At the moment, the supervision of the excavation is led by Juan Ignacio Morales and Artur Cebrià. The archaeological study of this site is included in a SERP project funded by the Department of Culture of the Catalan Government and another funded by the Ministry of Science, Innovation and Universities, headed by UB professor and SERP director Josep M Fullola.
The first signer of the article in Science Advances is Antonio Rodríguez Hidalgo, from the Institute of Evolution in Africa (IDEA). Other participants, apart from SERP members, are the researchers from Rovira i Virgili University, the Catalan Institute of Human Paleoecology and Social Evolution (IPHES), the Natural History Museum of Paris, the University of Salamanca, the University of Calgary (Canada) and the French National Centre for Scientific Research (CNRS).