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Princeton University

Princeton University

Princeton brings together graduate and undergraduate students to exchange ideas and experiences from all over the world and from all backgrounds.

Princeton’s John Hopfield receives Nobel Prize in physics

Hopfield, the Howard A. Prior Professor in the Life Sciences, Emeritus, and professor of molecular biology, emeritus, shares the 2024 Nobel Prize with Toronto’s Geoffrey E. Hinton.

Celebrating a Nobel born of curiosityPrinceton University

On Friday, Oct. 11, John Hopfield, winner of the 2024 Nobel Prize in Physics, was celebrated by colleagues, friends and students at a ceremony in the atrium of the Princeton Neuroscience Institute. Hopfield is Princeton’s Howard A. Prior Professor in the Life Sciences, Emeritus, and professor of molecular biology, emeritus. He holds associated faculty status in physics and neuroscience.

In Service of Humanity Princeton University

Princeton University has a longstanding commitment to service, reflected in Princeton’s informal motto — Princeton in the nation’s service and the service of humanity — and exemplified by the extraordinary contributions that Princetonians make to society.

 

The value of service is central to the mission of Princeton as a liberal arts university. It infuses the passions and pursuits of our students, faculty, staff and alumni, and is essential to how Princetonians serve the public good.

The University has reinforced its commitment to helping students and alumni use their educations to not only benefit themselves but also society more broadly. We push students, faculty and alumni to think about how their research, education and lives will benefit the nation, the world and humanity, and give them the support and resources to make it happen. Princeton University

Leading Lives of Purpose

Princetonians pursue service in many ways, such as through a profession, vocation or role.

With innovation and purpose, our students work with each other to propose and pursue civic engagement projects throughout their time at Princeton. Opportunities for engagement arise in classes and research supported by the Program for Community Engaged Scholarship (ProCES)(Link is external) (Link opens in new window), through student organizations and campus activities, and many have a home in the Pace Center for Civic Engagement(Link is external).

Our alumni engage in service across the world, participating in civic society and leading meaningful lives connected to a larger purpose and impact. Every year, more than 15,000 alumni volunteer(Link is external) to serve Princeton and University-sponsored projects. Alumni can serve with their class, regional associations, affiliated groups, the Association of Princeton Graduate Alumni(Link is external) and more. Annually at Alumni Day(Link is external), top honors go to an undergraduate alumnus and a graduate alumnus for their service to society.

Building Community Connections

Princeton-sponsored service programs offer positive ways for students, faculty and staff to engage with the larger community.

Among many initiatives supported by the University community are opportunities to serve as firefighters; donate bikes, food and clothing for charities; promote sustainability and environmental stewardship; and host educational and commemorative events, such as for Martin Luther King Jr. Day.

 

Emphasizing Commitment to Service

In 2016, Princeton’s informal motto was revised to “In the Nation’s Service and the Service of Humanity,” bridging phrases from Woodrow Wilson, Class of 1879, who served as president of Princeton before becoming president of the United States, and Supreme Court Justice Sonia Sotomayor, Class of 1976.

A medallion with the informal motto is set in the crossroads of the walkways on the front lawn of Nassau Hall.

 

Scholarship in the humanities forms and deepens us as individuals and as contributors to society. At a time when technology offers dazzling new possibilities and cultures collide in ways both exciting and dangerous, the arts and humanities provide crucial insight into what matters in life, into the character of civilization, and into the capacity — and the limits — of people’s ability to understand societies different from their own. Princeton University

 

From campus laboratories to biodiversity research in the Kenyan savannah to Antarctic edge-of-space balloon launches (seen at left), Princeton’s students and scholars are involved in inquiries across the scientific spectrum.

 

Whether improving national security, exploring issues of poverty, explaining human behavior or taking a critical look at international trade, research in the social sciences at Princeton strives to advance of knowledge of human society and address some of the largest societal problems of the 21st century. Princeton University

 

The School of Engineering and Applied Science is unique in combining the strengths of a world-leading research institution with the qualities of an outstanding liberal arts college. In both its teaching and research, Princeton engineering pursues fundamental knowledge as well as multidisciplinary collaborations that make technology effective in solving complex societal problems. The school is committed to preparing all students — engineers as well as students from across the University — to become leaders in a technology-driven society.

Princeton geneticists are rewriting the narrative of Neanderthals and other ancient humans

Ever since the first Neanderthal bones were discovered, people have wondered about these ancient hominins. How are they different from us? How much are they like us? Did our ancestors get along with them? Fight them? Love them? The recent discovery of a group called Denisovans, a Neanderthal-like group who populated Asia and Oceania, added its own set of questions. Princeton University

Now, an international team of geneticists and AI experts are adding whole new chapters to our shared hominin history. Under the leadership of Joshua Akey, a professor in Princeton’s Lewis-Sigler Institute for Integrative Genomics, the researchers have found a history of genetic intermingling and exchange that suggests a much more intimate connection between these early human groups than previously believed.

“This is the first time that geneticists have identified multiple waves of modern human-Neanderthal admixture,” said Liming Li, a professor in the Department of Medical Genetics and Developmental Biology at Southeast University in Nanjing, China, who performed this work as an associate research scholar in Akey’s lab. Princeton University

“We now know that for the vast majority of human history, we’ve had a history of contact between modern humans and Neanderthals,” said Akey. The hominins who are our most direct ancestors split from the Neanderthal family tree about 600,000 years ago, then evolved our modern physical characteristics about 250,000 years ago.

“From then until the Neanderthals disappeared — that is, for about 200,000 years — modern humans have been interacting with Neanderthal populations,” he said. Princeton University

The results(Link is external) of their work appear in the current issue of the journal Science.

Neanderthals, once stereotyped as slow-moving and dim-witted, are now seen as skilled hunters and tool makers who treated each other’s injuries with sophisticated techniques and were well adapted to thrive in the cold European weather. Princeton University

(Note: All of these hominin groups are humans, but to avoid saying “Neanderthal humans,” “Denisovan humans,” and “ancient-versions-of-our-own-kind-of-humans,” most archaeologists and anthropologists use the shorthand Neanderthals, Denisovans, and modern humans.)

Mapping the gene flow

Using genomes from 2,000 living humans as well as three Neanderthals and one Denisovan, Akey and his team mapped the gene flow between the hominin groups over the past quarter-million years.

The researchers used a genetic tool they designed a few years ago called IBDmix, which uses machine learning techniques to decode the genome. Previous researchers depended on comparing human genomes against a “reference population” of modern humans believed to have little or no Neanderthal or Denisovan DNA.

Akey’s team has established that even those referenced groups, who live thousands of miles south of the Neanderthal caves, have trace amounts of Neanderthal DNA, probably carried south by voyagers (or their descendants).

With IBDmix, Akey’s team identified a first wave of contact about 200-250,000 years ago, another wave 100-120,000 years ago, and the largest one about 50-60,000 years ago.

That contrasts sharply with previous genetic data. “To date, most genetic data suggests that modern humans evolved in Africa 250,000 years ago, stayed put for the next 200,000 years, and then decided to disperse out of Africa 50,000 years ago and go on to people the rest of the world,” said Akey.

“Our models show that there wasn’t a long period of stasis, but that shortly after modern humans arose, we’ve been migrating out of Africa and coming back to Africa, too,” he said. “To me, this story is about dispersal, that modern humans have been moving around and encountering Neanderthals and Denisovans much more than we previously recognized.”

That vision of humanity on the move coincides with the archaeological and paleoanthropological research suggesting cultural and tool exchange between the hominin groups.

A DNA insight

Li and Akey’s key insight was to look for modern-human DNA in the genomes of the Neanderthals, instead of the other way around. “The vast majority of genetic work over the last decade has really focused on how mating with Neanderthals impacted modern human phenotypes and our evolutionary history — but these questions are relevant and interesting in the reverse case, too,” said Akey.

They realized that the offspring of those first waves of Neanderthal-modern matings must have stayed with the Neanderthals, therefore leaving no record in living humans. “Because we can now incorporate the Neanderthal component into our genetic studies, we are seeing these earlier dispersals in ways that we weren’t able to before,” Akey said.

The final piece of the puzzle was discovering that the Neanderthal population was even smaller than previously believed.

Genetic modeling has traditionally used variation — diversity — as a proxy for population size. The more diverse the genes, the larger the population. But using IBDmix, Akey’s team showed that a significant amount of that apparent diversity came from DNA sequences that had been lifted from modern humans, with their much larger population.

As a result, the effective population of Neanderthals was revised down from about 3,400 breeding individuals down to about 2,400.

How Neanderthals vanished

Put together, the new findings paint a picture of how the Neanderthals vanished from the record, some 30,000 years ago.

“I don’t like to say ‘extinction,’ because I think Neanderthals were largely absorbed,” said Akey. His idea is that Neanderthal populations slowly shrank until the last survivors were folded into modern human communities.

This “assimilation model” was first articulated by Fred Smith, an anthropology professor at Illinois State University, in 1989. “Our results provide strong genetic data consistent with Fred’s hypothesis, and I think that’s really interesting,” said Akey.

“Neanderthals were teetering on the edge of extinction, probably for a very long time,” he said. “If you reduce their numbers by 10 or 20%, which our estimates do, that’s a substantial reduction to an already at-risk population.

“Modern humans were essentially like waves crashing on a beach, slowly but steadily eroding the beach away. Eventually we just demographically overwhelmed Neanderthals and incorporated them into modern human populations.”

 

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