Smithsonian's Human Origins Program

The plague (caused by the bacterium 𝑌𝑒𝑟𝑠𝑖𝑛𝑖𝑎 𝑝𝑒𝑠𝑡𝑖𝑠) is one of the most infamous pathogens in human history. A new study by Ruairidh Macleod and Frederik V. Seersholm at Københavns Universitet - University of Copenhagen and colleagues published new evidence of plague outbreaks from Lake Baikal, Siberia, dating back at least 5,500 years ago. This ancient strain lacks the genetic mutation that the "Black Death" in Medieval Europe had developed, yet still infected and spread among hunter-gatherer groups in at least two outbreaks. This changes scientists' understanding of how this disease spread and how mobile societies responded to pathogens.

Ancient DNA uncovers deadly plague outbreak among Siberian hunter-gatherers 5,500 years ago Plague is commonly associated with rats, crowded medieval cities, and the epidemics that swept across Europe during and after the Middle Ages. But a new study published in Nature shows that the disease was already lethal 5,500 years ago, when it killed humans in small, mobile hunter-gatherer communi...

One of the more pervasive trends in human evolution is increasing body size through time. Research by Jacob Gardner at University of Reading and colleagues looked at trends in estimated body size through time as it relates to evolutionary relationships among hominins. They found evidence for a general increase, broadly speaking, but split in two groups: 𝐴𝑢𝑠𝑡𝑟𝑎𝑙𝑜𝑝𝑖𝑡ℎ𝑒𝑐𝑢𝑠 and 𝐻𝑜𝑚𝑜 ℎ𝑎𝑏𝑖𝑙𝑖𝑠 follow a linear growth pattern over time, but remain somewhat small, and other members of the genus 𝐻𝑜𝑚𝑜 also get larger over time, but along a different linear path. Later small-bodied hominins like 𝐻𝑜𝑚𝑜 𝑓𝑙𝑜𝑟𝑒𝑠𝑖𝑒𝑛𝑠𝑖𝑠 do not fit either growth pattern.

New findings challenge idea that human bodies simply got bigger and bigger over time in a steady line The biggest jump in body size among our ancestors happened around 2–2.5 million years ago, with the appearance of Homo rudolfensis or Homo erectus/ergaster, rather than gradually across the whole human family tree.

Inequality is widespread in animal societies, but so are behaviors to limit the power of the animal in charge - according to new research. Typical behavioral studies usually focus on competition and how an alpha animal wields power or monopolizes resources. Danai Papageorgiou from the College for Life Sciences in Berlin and colleagues looked at animals including chimpanzees, hyenas, and guineafowl. The team found that the same behaviors that some humans use to check authority power are also present in these animals, including decreasing the alpha's social influence, challenging them via coalition, and removal from the group.

How animals use leveling behaviors to put alphas in their place Inequality is not unique to human groups and societies. Individuals with relatively little power possess a variety of behavioral strategies to counterbalance or regulate power differences. In humans, these strategies include criticism, ridicule, disobedience, or even the expulsion or ex*****on of po...

If you were to think about your social circle, you probably have a few close friends and family, a larger number of acquaintances, and an even larger number of relative strangers that you know. Turns out, chimpanzee social circles work in much the same way! Edwin J.C. van Leeuwen from Utrecht University and colleagues analyzed grooming behavior in our closest relatives to find chimp social circles approximate those of modern humans, with older chimps being more selective about close friends. Bonobos, however, distribute attention and grooming more evenly, like an egalitarian society.

Chimpanzees and bonobos have human-like friend circles, study finds Great apes appear to build friendships much like humans do. By studying grooming behavior, researchers discovered that chimpanzees and bonobos form close inner circles along with wider networks of weaker social connections. Chimpanzees focus on a few trusted partners and become more selective with a...

For today's Friday fun viewing, how did Neanderthal mucus help humans survive? Check out the YouTube short below featuring paleoanthropologist Ella Al-Shamahi explaining how Neanderthal DNA gave us a tactical advantage as we spread out of Africa, as far as South America.

How Neanderthal mucus helped us survive 🤤 Indigenous Americans carry high levels of Denisovans DNA in the MUC...

Talk about bringing history to life! While studying the mummified remains of the Ice Man, Ötzi, Mohamed Sarhan from Eurac Research and colleagues noticed a cold adapted yeast growing on his remains. This yeast infiltrated his remains shortly after he was killed 5,300 years ago and some of it survived through the ice to this present day. Some of this yeast might even be good for making sourdough which, according to the lead author, has already been tested. And it works. Yum.

'It was very very good': Ötzi the Iceman's body is covered in ancient yeast — and scientists just used it to make a sourdough A new study cultivated four strains of cold-adapted yeasts that had colonized Ötzi's body shortly after his death 5,300 years ago in the Alps.

To what degree do the spreading of people and ideas coincide in our past? According to a recent study by Nicholas Antonio da Sivla at Kiel University and colleagues, they may not go hand-in-hand. Looking at two Neolithic groups from six European sites, the team was interested in the degree of genetic relatedness in two archaeologically and culturally distinct peoples. They found that despite being separated by over 200 kilometers, the two groups were genetically homogenous, even closer knit than other groups of similar cultures.

'Patchwork families' existed more than 5,000 years ago, Neolithic DNA reveals Children from previous relationships growing up as siblings in a new family, couples adopting or fostering children: So-called patchwork families are a widespread way of life today. It is considered modern, but is in fact ancient, according to a recent analysis of human genetic material from the Neo...

Chimpanzees, like humans, have an unusually long adolescent period in their growth and development. Racha Reddy at The University of Utah studies the chimpanzees at Ngogo in Uganda to learn more about their behavior, and what it means for our own evolutionary history. In chimps, this period is vital in learning how to behave, and contribute, among adults in their natal group and beyond.

Chimpanzees' unusually protracted and vulnerable adolescences For all the diversity of the human condition, one experience is almost universally painful: adolescence. It's also unusual. Most other species pass from puberty to adulthood quickly, but humans linger for years in a transitional state, not quite children but not quite adults, either.

The shift from hunting and gathering to pastoralism may not have been as complete or sudden as previously believed. Kendra Chritz from University of British Columbia and colleagues looked isotopes of individuals between 9,500 and 230 years ago to track how diet changed between different groups. They found that there was remarkable dietary diversity in hunter-gatherers as well as persistent dietary diversity in early pastoralists, indicating that despite raising domesticated cattle, they still relied on hunting and gathering for a long time.

Even after adopting cattle, early herders kept hunting and gathering Eastern Africa’s earliest livestock herders continued fishing, hunting and gathering for centuries, which may have helped them adapt to a changing climate.

Two hominins living at Sterkfontein in South Africa at the same time had different posture and locomotion. Marine Cazenave from the Max Planck Institute for Evolutionary Anthropology and colleagues describe the bone structure of a recently discovered 𝑃𝑎𝑟𝑎𝑛𝑡ℎ𝑟𝑜𝑝𝑢𝑠 𝑟𝑜𝑏𝑢𝑠𝑡𝑢𝑠 femur (thigh bone) and tibia (shin bone). Compared with its neighbor 𝐴𝑢𝑠𝑡𝑟𝑎𝑙𝑜𝑝𝑖𝑡ℎ𝑒𝑐𝑢𝑠 𝑎𝑓𝑟𝑖𝑐𝑎𝑛𝑢𝑠, 𝑃𝑎𝑟𝑎𝑛𝑡ℎ𝑟𝑜𝑝𝑢𝑠 lower limbs were built for more frequent hip, knee, and ankle flexion. This could indicate that thy were climbing more often, or engaging in other behaviors like squatting.

Swartkrans Paranthropus and Sterkfontein Australopithecus  had different locomotor repertoires Paranthropus robustus from southern Africa combined upright walking and more frequent climbing than the older Australopithecus in the same region