What makes us human? The answer may be found in overlooked DNA

by Cell Press

Graphical abstract. Credit: https://doi.org/10.1016/j.stem.2021.09.008

Our DNA is very similar to that of the chimpanzee, which in evolutionary terms is our closest living relative. Stem cell researchers at Lund University in Sweden have now found a previously overlooked part of our DNA, so-called non-coded DNA, that appears to contribute to a difference which, despite all our similarities, may explain why our brains work differently. The study is published in the journal Cell Stem Cell.

The chimpanzee is our closest living relative in evolutionary terms and research suggests our kinship derives from a common ancestor. About five to six million years ago, our evolutionary paths separated, leading to the chimpanzee of today, and Homo Sapiens, humankind in the 21st century.

In a new study, stem cell researchers at Lund examined what it is in our DNA that makes human and chimpanzee brains different—and they have found answers.

"Instead of studying living humans and chimpanzees, we used stem cells grown in a lab. The stem cells were reprogrammed from skin cells by our partners in Germany, the U.S. and Japan. Then we examined the stem cells that we had developed into brain cells," explains Johan Jakobsson, professor of neuroscience at Lund University, who led the study.

Using the stem cells, the researchers specifically grew brain cells from humans and chimpanzees and compared the two cell types. The researchers then found that humans and chimpanzees use a part of their DNA in different ways, which appears to play a considerable role in the development of our brains.

"The part of our DNA identified as different was unexpected. It was a so-called structural variant of DNA that were previously called "junk DNA," a long repetitive DNA string which has long been deemed to have no function. Previously, researchers have looked for answers in the part of the DNA where the protein-producing genes are—which only makes up about two percent of our entire DNA—and examined the proteins themselves to find examples of differences."

The new findings thus indicate that the differences appear to lie outside the protein-coding genes in what has been labeled as "junk DNA," which was thought to have no function and which constitutes the majority of our DNA.

"This suggests that the basis for the human brain's evolution are genetic mechanisms that are probably a lot more complex than previously thought, as it was supposed that the answer was in those two percent of the genetic DNA. Our results indicate that what has been significant for the brain's development is instead perhaps hidden in the overlooked 98 percent, which appears to be important. This is a surprising finding."

The stem cell technique used by the researchers in Lund is revolutionary and has enabled this type of research. The technique was recognized by the 2012 Nobel Prize in Physiology or Medicine. It was the Japanese researcher Shinya Yamanaka who discovered that specialized cells can be reprogrammed and developed into all types of body tissue. And in the Lund researchers' case, into brain cells. Without this technique, it would not have been possible to study the differences between humans and chimpanzees using ethically defensible methods.

Why did the researchers want to investigate the difference between humans and chimpanzees?

"I believe that the brain is the key to understanding what it is that makes humans human. How did it come about that humans can use their brain in such a way that they can build societies, educate their children and develop advanced technology? It is fascinating!"

Johan Jakobsson believes that in the future the new findings may also contribute to genetically-based answers to questions about psychiatric disorders, such as schizophrenia, a disorder that appears to be unique to humans.

"But there is a long way to go before we reach that point, as instead of carrying out further research on the two percent of coded DNA, we may now be forced to delve deeper into all 100 percent—a considerably more complicated task for research," he concludes.Scientists discover how humans develop larger brains than other apes

More information: Pia A. Johansson et al, A cis-acting structural variation at the ZNF558 locus controls a gene regulatory network in human brain development, Cell Stem Cell (2021). doi.org/10.1016/j.stem.2021.09.008

Journal information: Cell Stem Cell 

Provided by Cell Press 

Fossils and ancient DNA paint a vibrant picture of human origins
A century of science has begun to explain how and where Homo sapiens and our kin evolved

A century ago, scientists knew almost nothing about our ancient ancestors, but have since discovered a wide range of relatives.
THE NATURAL HISTORY MUSEUM/ALAMY STOCK PHOTO


By Erin Wayman

SEPTEMBER 15, 2021 AT 10:30 AM


In The Descent of Man, published in 1871, Charles Darwin hypothesized that our ancestors came from Africa. He pointed out that among all animals, the African apes — gorillas and chimpanzees — were the most similar to humans. But he had little fossil evidence. The few known human fossils had been found in Europe, and those that trickled in over the next 50 years came from Europe and from Asia.

Had Darwin picked the wrong continent?

Finally, in 1924, a fortuitous find supported Darwin’s speculation. Among the debris at a limestone quarry in South Africa, miners recovered the fossilized skull of a toddler. Based on the child’s blend of humanlike and apelike features, an anatomist determined that the fossil was what was then popularly known as a “missing link.” It was the most apelike fossil yet found of a hominid — that is, a member of the family Hominidae, which includes modern humans and all our close, extinct relatives.

That fossil wasn’t enough to confirm Africa as our homeland. Since that discovery, paleoanthropologists have amassed many thousands of fossils, and the evidence over and over again has pointed to Africa as our place of origin. Genetic studies reinforce that story. African apes are indeed our closest living relatives, with chimpanzees more closely related to us than to gorillas. In fact, many scientists now include great apes in the hominid family, using the narrower term “hominin” to refer to humans and our extinct cousins.

In a field with a reputation for bitter feuds and rivalries, the notion of humankind’s African origins unifies human evolution researchers. “I think everybody agrees and understands that Africa was very pivotal in the evolution of our species,” says Charles Musiba, a paleoanthropologist at the University of Colorado Denver.

Paleoanthropologists have sketched a rough timeline of how that evolution played out. Sometime between 9 million and 6 million years ago, the first hominins evolved. Walking upright on two legs distinguished our ancestors from other apes; our ancestors also had smaller canine teeth, perhaps a sign of less aggression and a change in social interactions. Between about 3.5 million and 3 million years ago, humankind’s forerunners ventured beyond wooded areas. Africa was growing drier, and grasslands spread across the continent. Hominins were also crafting stone tools by this time. The human genus, Homo, arrived between 2.5 million and 2 million years ago, maybe earlier, with larger brains than their predecessors. By at least 2 million years ago, Homo members started traveling from Africa to Eurasia. By about 300,000 years ago, Homo sapiens, our species, emerged.

All in the family

Fossil finds suggest that many hominin species have lived over the last 7 million years (dates for each species are based on those finds), though researchers debate the validity of some of these classifications. The earliest purported hominins (purple) show some signs of upright walking, which became more routine with the rise of Australopithecus (green). Seemingly short-lived Paranthropus (yellow) was adapted for heavy chewing, and brain size began to increase in Homo species (blue).
H. THOMPSON

But human evolution was not a gradual, linear process, as it appeared to be in the 1940s and ’50s. It did not consist of a nearly unbroken chain, one hominin evolving into the next through time. Fossil discoveries in the ’60s and ’70s revealed a bushier family tree, with many dead-end branches. By some counts, more than 20 hominin species have been identified in the fossil record. Experts disagree on how to classify all of these forms — “Fossil species are mental constructs,” a paleoanthropologist once told Science News — but clearly, hominins were diverse, with some species overlapping in both time and place.

Even our species wasn’t always alone. Just 50,000 years ago, the diminutive, 1-meter-tall Homo floresiensis, nicknamed the hobbit, lived on the Indonesian island of Flores. And 300,000 years ago, Homo naledi was a neighbor in South Africa.

Finding such “primitive” species — both had relatively small brains — living at the same time as H. sapiens was a big surprise, says Bernard Wood, a paleoanthropologist at George Washington University in Washington, D.C. Those discoveries, made within the last two decades, were reminders of how much is left to learn.

It’s premature to pen a comprehensive explanation of human evolution with so much ground — in Africa and elsewhere — to explore, Wood says. Our origin story is still a work in progress.

Raymond Dart had a wedding to host.

It was a November afternoon in 1924, and the Australian-born anatomist was partially dressed in formal wear when he was distracted by fossils. Rocks containing the finds had just been brought to his home in Johannesburg, South Africa, from a mine near the town of Taung.

Raymond Dart recognized that the Taung Child (shown with Dart decades after its 1924 discovery) had both apelike and humanlike qualities. The find sparked the search for more hominin fossils in Africa.

SCIENCE HISTORY IMAGES/ALAMY STOCK PHOTO

Imprinted on a knobby rock about as big as an orange were the folds, furrows and even blood vessels of a brain. It fit perfectly inside another rock that had a bit of jaw peeking out.

The groom pressed Dart to get back on track. “My god, Ray,” he said. “You’ve got to finish dressing immediately — or I’ll have to find another best man.”

As soon as the festivities ended, Dart, 31 years old at the time, started removing the jaw from its limestone casing, chipping away with knitting needles. A few weeks later, he had liberated not just a jaw but a partial skull preserving the face of a child.

On February 7, 1925, in the journal Nature, Dart introduced the Taung Child to the world. He described the fossil as an ape like no other, one with some distinctly humanlike features, including a relatively flat face and fairly small canine teeth. The foramen magnum, the hole through which the spinal cord exits the head, was positioned directly under the skull, implying the child had an erect posture and walked on two legs.

Dart concluded that the Taung Child belonged to “an extinct race of apes intermediate between living anthropoids and man.” His italicized text emphasized his judgment: The fossil was a so-called missing link between other primates and humans. He named it Australopithecus africanus, or southern ape of Africa.

The Taung Child was the second hominin fossil discovered in Africa, and much more primitive than the first. Dart argued that the find vindicated Darwin’s belief that humans arose on that continent. “There seems to be little doubt,” Science News Letter, the predecessor of Science News, reported, “that there has been discovered on the reputed ‘dark’ continent a most important step in the evolutionary history of man.”

But Dart’s claims were mostly met with skepticism. It would take more than two decades of new fossil finds and advances in geologic dating for Dart to be vindicated — and for Africa to become the epicenter of paleoanthropology.

Hot spots

This map marks locations of some of human evolution’s biggest fossil discoveries. The search in Africa began in the 1920s. Yet there is still much of the continent left to explore, as paleoanthropologists have mostly focused on eastern and southern Africa.

A. The oldest known Homo sapiens fossils, dating to about 300,000 years ago, come from Jebel Irhoud in Morocco.

B. At the Toros-Menalla site in Chad, scientists found what may be the earliest known hominin, Sahelanthropus tchadensis.

C. Ethiopia’s Afar region hosts numerous sites, some stretching back more than 5 million years. Major finds include the early hominin Ardipithecus and Lucy.

D. Southern Ethiopia and northern Kenya hold a long hominin history, including Australopithecus fossils, some of the oldest known stone tools, early Homo fossils and early H. sapiens fossils.

E. Louis and Mary Leakey put Tanzania’s Olduvai Gorge on the map with discoveries of Paranthropus boisei and Homo habilis. The nearby Laetoli site preserves hominin footprints dating to 3.6 million years ago.

F. The Kabwe skull, the first hominin fossil found in Africa, came from a mine in Zambia in 1921.

G. South Africa’s limestone caves have yielded Australopithecus, Paranthropus and Homo fossils.

H. Quarry workers near Taung, South Africa, recovered the first Australopithecus fossil ever found.

I. At caves along coastal South Africa, scientists have recovered a rich record of H. sapiens activity, including what may be the earliest known drawing and other signs of symbolic behavior.
SOURCE: NATIONAL RESEARCH COUNCIL/UNDERSTANDING CLIMATE’S INFLUENCE ON HUMAN EVOLUTION 2010; ADAPTED BY E. OTWELL

Against the establishment

Unlike Darwin, many evolutionists of the late 19th and early 20th centuries had theorized that the human family tree was rooted in Asia. Some argued that Asia’s gibbons were our closest living relatives. Others reasoned that tectonic activity and climate change in Central Asia sparked human evolution. One naturalist even proposed that human origins traced back to a lost continent that had sunk in the Indian Ocean, forcing our ancestors to relocate to Southeast Asia.

And that’s where the best contender for an early human ancestor had been found. In the 1890s, a crew led by Dutch physician-turned-anthropologist Eugène Dubois had uncovered a skullcap and thigh bone on the Indonesian island of Java. The thick skullcap had heavy brow ridges, but Dubois estimated it once held a brain that was about twice as big as an ape’s and approaching the size of a human’s. The thigh bone indicated that this Java Man, later named Homo erectus, walked upright.

Europe had its own tantalizing fossils. Neandertals had been known since the mid-19th century, but by the early 20th century, they were generally thought to be cousins that lived too recently to shed much light on our early evolution. A more relevant discovery seemed to come in 1912, when an amateur archaeologist had recovered humanlike bones from near Piltdown, England; the site also contained fossils of extinct creatures, suggesting Piltdown Man was of great antiquity. Skull bones hinted he had a human-sized brain, but his primitive jaw had a large, apelike canine tooth.

Some experts questioned whether the skull and jaw belonged together. But British scientists embraced the discovery — and not just because it implied England had a role in human origins. Piltdown Man’s features fit with the British establishment’s view of human evolution, in which a big brain was the first trait to distinguish human ancestors from other apes.

So when Dart announced that he had found a small-brained bipedal ape with humanlike teeth in the southern tip of Africa, scientists were primed to be skeptical, says Paige Madison, a historian of science at the Natural History Museum of Denmark in Copenhagen. Scientists were also skeptical of Dart. While a student in London, he had earned a reputation as a “scientific heretic, given to sweeping claims,” according to a paper coauthored by a colleague.

But initial criticism focused mostly on practical concerns, says Madison, who has studied the skeptics’ reactions. “I found what they were actually saying on paper to be quite reasonable.”

A big problem: Dart’s fossil was of a 3- or 4-year-old child. Critics pointed out that a young ape tends to resemble humans in some ways, but the similarities disappear as the ape matures. Critics also complained that Dart hadn’t done proper comparative analyses with young chimps and gorillas, and he refused to send the fossil to England where such analyses could be done. This refusal irked the British old guard. “It was unpalatable to the scientists in England that the young colonial upstart had presumed to describe the skull himself,” one of Dart’s contemporaries later wrote, “instead of submitting it to his elders and betters.”

It’s hard not to wonder how the era’s colonialist and racist attitudes shaped perceptions. The Taung Child came to light at a time when eugenics was still considered legitimate science, and much of anthropology was devoted to categorizing people into races and arranging them into hierarchies. On the one hand, Western researchers tended to maintain the perverse notion that Africans are more primitive than other people, even less evolved. On the other, they wanted to believe Europe or Asia is where humans originated.

How these views influenced reactions to the Taung Child is not clear-cut. Many skeptics didn’t cite the fossil’s location as a problem, and some acknowledged humans could have evolved in Africa. But deep-seated biases may have made it easier for some researchers to reject the Taung Child and accept Piltdown Man, even though fossil evidence for that claim was also scant, says Sheela Athreya, a paleoanthropologist at Texas A&M University in College Station.

Newspapers worldwide followed the Taung Child controversy. And while fans sent Dart poems and short stories casting the child as a national hero, he also received letters from disapproving creationists.

Amid it all, Dart had convinced at least one well-known scientist. Robert Broom, a Scottish-born physician living in South Africa and an authority on reptile evolution, recognized that fossils of fully grown A. africanus individuals would be needed to confirm that the Taung Child’s humanlike qualities were retained in adulthood.

In the 1930s and ’40s, Robert Broom unearthed fossils in South African caves, including at Sterkfontein (shown), that helped convince skeptics that Australopithecus was a human ancestor.

NATURAL HISTORY, 1947 (LINDA HALL LIBRARY)

Broom began to find just that evidence in 1936 in caves not far from Johannesburg. Often taking the heavy-handed approach of detonating dynamite to free specimens, he amassed a collection of fossils representing both the young and the old. Limb, spine and hip bones confirmed South Africa was once home to a bipedal ape, and skull bones verified Dart’s inferences about A. africanus’ humanlike teeth.

Even the staunchest Dart doubters couldn’t overlook this evidence. British anatomist Arthur Keith, who had once called Dart’s assertions “preposterous,” conceded. “I am now convinced,” he wrote in a one-paragraph letter to Nature in 1947, “that Prof. Dart was right and that I was wrong; the Australopithecinae are in or near the line which culminated in the human form.”

A few years later, in 1953, researchers exposed Piltdown Man to be a hoax — someone had planted a modern human skull alongside an orangutan jaw with its teeth filed down. Many experts outside of England had never been convinced by the find in the first place. “It was not a complete surprise when he was proved to be a fake,” Science News Letter reported.

Still, Africa’s role in human evolution was not cemented. From the time of the Taung Child’s unearthing through World War II, discoveries of hominin fossils continued in Indonesia and at a cave site near Beijing called Zhoukoudian. These fossils kept the focus on Asia

.

Olduvai Gorge in Tanzania’s eastern Serengeti Plains was home to a lake millions of years ago. Nearby volcanic eruptions helped preserve fossils at the site and enable dating of the finds.

NOEL FEANS/FLICKR (CC BY 2.0)

A series of surprises

It was ultimately a series of discoveries by the husband-wife paleoanthropologists Louis and Mary Leakey that shifted the focus. Louis, who had grown up in East Africa as the son of English missionaries, had long believed Africa was the human homeland. While Broom was scouring South Africa in the 1930s, the Leakeys began exploring Olduvai Gorge in what is now Tanzania.

Year after year, the pair failed to find hominin fossils. But they dug up stone tools, suggesting that hominins must have lived there. So they kept looking. One day in 1959, while an ill Louis stayed behind in camp, Mary discovered a skull with small canine teeth like Australopithecus. But the fossil’s giant molar teeth, flaring cheekbones and bony crest running along the top of the skull where massive chewing muscles would have attached suggested something else. Nicknamed Nutcracker Man for its chompers, the species was dubbed Zinjanthropus boisei (it’s now called Paranthropus boisei because it is clearly a close cousin of P. robustus, a South African species found by Broom).

Louis and Mary Leakey spent decades digging in East Africa’s Olduvai Gorge (above) before finding hominin fossils. Their luck changed in 1959 when Mary found a skull belonging to an ancient human relative now known as Paranthropus boisei (below).

ACC. 90-105 – SCIENCE SERVICE, RECORDS, 1920S-1970S, SMITHSONIAN INSTITUTION ARCHIVES/FLICKR

Paranthropus boisei

HUMAN ORIGINS PROGRAM, NMNH, SMITHSONIAN INSTITUTION

Until the Zinjanthropus discovery, determining a hominin fossil’s age was largely a guessing game because there was no good way to measure how long ago an ancient fossil had formed. But advances in nuclear physics in the early and mid-20th century led to radioactive dating techniques that allowed age calculations. Using potassium-argon dating, geologists reported in 1961 that Zinjanthropus came from a rock layer about 1.75 million years old. The fossil was three times older than the Leakeys initially suspected. (Later, A. africanus proved to be even older, living about 2 million to 3 million years ago.) The discovery vastly stretched the timescales on which researchers were mapping human evolution.

The surprises didn’t end there. In the early 1960s, the Leakeys’ team recovered fossils of a hominin that lived at roughly the same time as Zinjanthropus but had smaller, more humanlike teeth and a brain notably bigger than that of both Zinjanthropus and Australopithecus. Because of the elevated brain size and details of the hand, the Leakeys argued that this hominin was the one who made the tools at Olduvai Gorge; in 1964, Louis and colleagues placed it in the human genus with the name Homo habilis, or handy man.

The Homo designation was controversial, and to this day paleoanthropologists debate how to classify these fossils. Still, the discoveries at Olduvai Gorge kicked off a paleo-anthropological gold rush in Africa. A 1974 discovery in Ethiopia, for instance, once again expanded the timescale of human evolution. It was one of the most famous discoveries in all of human evolution: the nearly 40 percent complete skeleton of Lucy, known more formally as Australopithecus afarensis, who lived about 3.2 million years ago.

Since then, researchers have shown repeatedly that the hominin fossil record stretches farthest back in Africa. Today, the oldest purported hominins date back some 6 million or 7 million years — to around the time when the ancestors of humans and chimpanzees probably parted ways.

The skeleton known as Lucy, discovered in Ethiopia in 1974, helped confirm that our ancient ancestors evolved upright walking long before big brains.

JOHN KAPPELMAN/UNIV. OF TEXAS AT AUSTIN

On the origin of our species

Even after it became clear that hominins originated in Africa, it was still uncertain where our species, Homo sapiens, began. By the 1980s, paleoanthropologists had largely settled into two camps. One side claimed that, like the earliest hominins, modern humans came from someplace in Africa. The other side championed a more diffuse start across Africa, Asia and Europe.

That same decade saw researchers increasingly relying on genetics to study human origins. Initially, scientists looked to modern people’s DNA to make inferences about ancient populations. But by the late 1990s, geneticists pulled off a feat straight out of science fiction: decoding DNA preserved in hominin fossils.

For paleoanthropologists, studying ancient DNA has been like astronomers getting a new telescope that sees into deep space with a new wavelength of light. It’s revealing things no one even thought to look for, says paleoanthropologist John Hawks of the University of Wisconsin–Madison. “That is the most powerful thing that genetics has handed us.”

And it’s revealed a truly tangled tale.
A trellis or a candelabra

Long before the rise of genetics, or even the discovery of many hominin fossils, unraveling human origins was a quest to explain how the world’s different races came to be. But after the horrors of World War II, anthropologists started to question the validity of race.

“This was a real moral hinge point in the science,” Hawks says. “It was a realization that viewing things through the perspective of race was creating evils in the world.” And it was scientifically dubious, as genetic evidence has shown that people are all so similar that race is more of a cultural concept than a biological phenomenon. Humans, in fact, are less genetically diverse than chimps.

As race was de-emphasized in the 1940s and ’50s, anthropologists started to think more about the mechanisms of evolution and how populations change over time, a direct influence of the “modern synthesis” that had united Darwinian evolution and genetics.

One influential forerunner to this period was anatomist and anthropologist Franz Weidenreich. After leaving Nazi Germany in the 1930s, he ended up in China studying fossils known as Peking Man (now classified as H. erectus), who lived several hundred thousand years ago. Weidenreich noticed that Peking Man shared certain features, such as shovel-shaped incisor teeth, with some present-day East Asians.

From this observation of apparent regional continuity across time, he concluded there had never been just one real-life Garden of Eden. As he wrote in 1947, “Man has evolved in different parts of the old world.”

Rather than picturing a family tree with one main trunk and branches, he envisioned human evolution as a trellis. Vertical lines represented groups of humans from different geographic regions, with the crisscrossing lines of the lattice representing mating between groups. Such gene flow enabled ancient forms across Africa, Asia and Europe to stay a unified species that gradually evolved into modern humans, with some regional variation maintained.

One consequence of all that mixing: “Pure” races never existed.

But a minority of researchers clung to the idea that race was central to understanding human evolution. In 1962, American anthropologist Carleton Coon transformed Weidenreich’s trellis into a candelabra, trimming away the intersecting lines. He argued that modern races stemmed from a common ancestor, but different lines independently evolved into H. sapiens, with races crossing the “sapiens” boundary at different times. In his view, Science News Letter explained, “the Negro race is at least 200,000 years behind the white race on the ladder of evolution.”

It’s a deeply disturbing statement to type today, and it was rejected by many at the time. Coon published his claims during the height of the U.S. civil rights movement, less than a year before Martin Luther King Jr. stood on the steps of the Lincoln Memorial and shared his dream of racial equality. Advocates of segregation cited the supposed evidence of inferiority to justify their racist agenda. But many experts discounted Coon’s views. It’s an “extreme opinion,” one anthropologist told Science News Letter in 1962, lacking “evidence of any nature to support it.”

Still, Coon’s claims tarnished Weidenreich’s view of human evolution. And in the 1960s and ’70s, interest shifted to much earlier stages of hominin history, many millions of years ago.

Homo sapiens arrives, somehow

In the mid-1980s, anthropologists went back to disentangling the roots of H. sapiens. By then, a basic picture had emerged: Hominins arose in Africa, and H. erectus was the first to venture outside of it, by what we now know was nearly 2 million years ago. In some places, H. erectus persisted for a long time; elsewhere, new groups appeared, such as Neandertals (H. neanderthalensis) in Europe and Asia. At some point, somehow, H. sapiens arrived and its predecessors vanished.

T.D. WHITE ET AL/NATURE 2003

Some of the oldest fossils classified as Homo sapiens still lack some features typical of people today. For instance, a roughly 300,000-year-old skull (top) from Jebel Irhoud in Morocco has a relatively long, flat braincase. Only later does a tall, rounded braincase appear to evolve, as seen in a 195,000-year-old skull (middle, white fills in missing pieces) from Omo Kibish and a 160,000-year-old skull (bottom) from Herto, both in Ethiopia.

That “somehow” became a matter of debate in the 1980s, ’90s and into the 2000s.

Milford Wolpoff, a paleoanthropologist at the University of Michigan in Ann Arbor, and colleagues revived the latticework of Weidenreich’s trellis model in the 1980s. Under this “multiregional” view, it was difficult to draw a clean line between the end of H. erectus and the beginning of H. sapiens. In fact, Wolpoff argued that H. erectus and other seemingly distinct groups should be folded into our species. Through intergroup mating these earlier “archaic” H. sapiens gradually evolved the features of “anatomically modern” humans.

Critics doubted there could have been enough intergroup mating back then to allow a small, globally scattered population to remain as one. Chris Stringer, a paleoanthropologist at the Natural History Museum in London, and colleagues proposed instead that H. sapiens originated in just one place — descending from H. erectus or a subsequent species — and then spread across the world. Along the way, these humans replaced other hominins, including Neandertals.

Both theories were difficult to test. For instance, the single-origin idea predicted that the oldest modern human fossils should all be found in just one region. But there weren’t many well-dated fossils from the relevant time period. And seeing ourselves in the fossil record proved challenging. Researchers disagreed on what features defined modern humans. A globular head? A flat face? Something as banal as a chin? These disagreements meant researchers on both sides could often look at the same fossil data and claim support for their position.

Genetic revolution

By the 1980s, DNA offered a new way to investigate the deep past. In 1987, one genetic study shifted momentum toward the single-origin theory, with Africa as the point of origin.

Researchers at the University of California, Berkeley analyzed mitochondrial DNA from people around the world. Because it’s inherited from mother to child and undergoes no genetic reshuffling, mitochondrial DNA preserves a record of maternal ancestry. African populations showed the greatest genetic diversity. And when the team built a family tree using the genetic data, it had two main branches: One held only African lineages and the other contained lineages from all over the world, including Africa. This pattern suggested the “mother” lineage came from Africa. Based on the estimated rate at which mitochondrial DNA accumulates changes, the team calculated that this African Eve lived about 200,000 years ago.

“Thus,” the team reported in Nature, “we propose that Homo erectus in Asia was replaced without much mixing with the invading Homo sapiens from Africa.”

Like fossils, genetic evidence is open to interpretation. Proponents of multiregional evolution pointed out that the African diversity may not be indicative of greater antiquity but simply a sign that African populations were much larger than other ancient groups. Mitochondrial DNA also isn’t a complete record of the past — given its unusual inheritance, lineages are easily lost over time.

Even with those warnings, the “Out of Africa” model gained followers as genetic evidence piled up. And in the late 1980s, 1990s and early 2000s, new dating techniques and discoveries suggested the earliest H. sapiens fossils came from Africa, at sites in Ethiopia dating to between 195,000 and 160,000 years ago. More recently, scientists linked roughly 300,000-year-old Moroccan fossils to H. sapiens.

A new window into the past opened in 1997. A team led by Svante Pääbo, a geneticist now at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, recovered mitochondrial DNA from a Neandertal fossil. It was so different from any modern human’s DNA that it suggested Neandertals must be a separate species. That was another blow to the multiregional model.

But paleoanthropology is like solving a jigsaw puzzle without all the pieces; any new piece can change the picture. That’s what happened in 2010. When Pääbo and colleagues assembled the Neandertal’s genetic blueprint, or genome, and compared it with modern human DNA, the team came to a startling conclusion: About 1 to 4 percent of DNA in non-Africans today came from Neandertals.

“We were naïve to think that humans just marched out of Africa, killed some Neandertals and populated the world,” archaeologist John Shea of Stony Brook University in New York later told Science News.

That genetic data seemed to support a compromise model between Out of Africa and multiregionalism. Yes, modern humans originated in Africa, the idea went, but once they expanded into new territories, they mated with other hominins. Hints of such hybridization had been reported in the late ’90s, when some researchers claimed an ancient skeleton from Portugal had a mix of Neandertal and human features.

Interbreeding wasn’t the only shock to come in 2010. Pääbo’s group also analyzed DNA from a finger bone found at Siberia’s Denisova Cave. Both Neandertals and modern humans had once lived there, but the DNA didn’t match either group. For the first time, genetics had revealed a new hominin. These Denisovans are still mysterious, known from only a few bits of bone and teeth, but they too interbred with humans. For instance, Denisovan DNA accounts for about 2 to 4 percent of Melanesian people’s genome.
It’s complicated

Over the last decade, as genetic and fossil revelations have painted a more complex picture of human origins, paleoanthropologists have moved beyond both the multiregional and simple Out of Africa scenarios. Rather than a tree with separate branches or a trellis, human evolution was probably more like a braided stream, a concept traced to paleoanthropologist Xinzhi Wu of the Chinese Academy of Sciences in Beijing, who used a river metaphor to describe patterns of human evolution in China. Different human populations may have emerged, with some floating away and petering out and others connecting to varying degrees.

One emerging view suggests that much of early human evolution occurred in Africa, but there was not one place on the continent where H. sapiens was born. Starting at least 300,000 years ago, modern H. sapiens features start to show up in the fossil record. But these features didn’t arise all together. Only through the mating of different populations across Africa did the suite of behavioral and biological traits that define us today crystallize, says Eleanor Scerri, an evolutionary archaeologist at the Max Planck Institute for the Science of Human History in Jena, Germany.

“Our origins lie in the interactions of these different populations,” she says. Understanding those interactions is limited by how little of ancient Africa researchers have explored so far. Western, central and much of northern Africa are terra incognita.

There’s still much to explore in other parts of the world too. A single, unifying explanation of human origins may not be possible, as different evolutionary processes probably shaped human history in different regions, says Athreya, of Texas A&M University.

Making more progress on understanding those processes and our roots will come from new discoveries, technological advances and, importantly, new perspectives. For the last 100 years, our origin story has been told by mostly white, mostly male scientists. Welcoming a more diverse group of researchers into paleoanthropology, Athreya says, will reveal blind spots and biases as scientists add to and amend the tale.

This is, after all, everyone’s story.

About Erin Wayman is the magazine managing editor. She has a master’s degree in biological anthropology from the University of California, Davis and a master’s degree in science writing from Johns Hopkins University.

Would we still see ourselves as ‘human’ if other hominin species hadn’t gone extinct?

Would we see Neanderthals (right) as human if they were around today? 

wikipedia, CC BY-SA

October 7, 2021

READER QUESTION: We now know from evolutionary science that humanity has existed in some form or another for around 2 million years or more. Homo sapiens are comparatively new on the block. There were also many other human species, some which we interbred with. The question is then inevitable – when can we claim personhood in the long story of evolution? Are Chimpanzees people? Did Australopithecine have an afterlife? What are the implications for how we think about rights and religion?

 Anthony A. MacIsaac, 26, Paris, France.

In our mythologies, there’s often a singular moment when we became “human”. Eve plucked the fruit of the tree of knowledge and gained awareness of good and evil. Prometheus created men from clay and gave them fire. But in the modern origin story, evolution, there’s no defining moment of creation. Instead, humans emerged gradually, generation by generation, from earlier species.

The creation of Adam by Michelangelo. wikipedia

As with any other complex adaptation – a bird’s wing, a whale’s fluke, our own fingers – our humanity evolved step by step, over millions of years. Mutations appeared in our DNA, spread through the population, and our ancestors slowly became something more like us and, finally, we appeared.

This article is part of Life’s Big Questions
The Conversation’s new series, co-published with BBC Future, seeks to answer our readers’ nagging questions about life, love, death and the universe. We work with professional researchers who have dedicated their lives to uncovering new perspectives on the questions that shape our lives.

Strange apes, but still apes

People are animals, but we’re unlike other animals. We have complex languages that let us articulate and communicate ideas. We’re creative: we make art, music, tools. Our imaginations let us think up worlds that once existed, dream up worlds that might yet exist, and reorder the external world according to those thoughts. Our social lives are complex networks of families, friends and tribes, linked by a sense of responsibility towards each other. We also have awareness of ourselves and our universe: sentience, sapience, consciousness, whatever you call it.

And yet the distinction between ourselves and other animals is, arguably, artificial. Animals are more like humans than we might think – or like to think. Almost all behaviour we once considered unique to ourselves are seen in animals, even if they’re less well developed.

Gorillas use tools too. dean bertoncelj/Shutterstock

That’s especially true of the great apes. Chimps, for example, have simple gestural and verbal communication. They make crude tools, even weapons, and different groups have different suites of tools – distinct cultures. Chimps also have complex social lives and cooperate with each other.

As Darwin noted in Descent of Man, almost everything odd about Homo sapiens – emotion, cognition, language, tools, society – exists, in some primitive form, in other animals. We’re different, but less different than we think.

And in the past, some species were far more like us than other apes – Ardipithecus, Australopithecus, Homo erectus and Neanderthals. Homo sapiens is the only survivor of a once diverse group of humans and human-like apes, the hominins, which includes around 20 known species and probably dozens of unknown species.

The extinction of those other hominins wiped out all the species that were intermediate between ourselves and other apes, creating the impression that some vast, unbridgeable gulf separates us from the rest of life on Earth. But the division would be far less clear if those species still existed. What looks like a bright, sharp dividing line is really an artefact of extinction.

The discovery of these extinct species now blurs that line again and shows how the distance between us and other animals was crossed – gradually, over millennia.
The evolution of humanity

Our lineage probably split from the chimpanzees around 6 million years ago. These first hominins, members of the human line, would barely have seemed human, however. For the first few million years, hominin evolution was slow.

The first big change was walking upright, which let hominins move away from forests into more open grassland and bush. But if they walked like us, nothing else suggests the first hominins were any more human than chimps or gorillas. Ardipithecus, the earliest well-known hominin, had a brain that was slightly smaller than a chimp’s, and there’s no evidence they used tools.

In the next million years, Australopithecus appeared. Australopithecus had a slightly larger brain – larger than a chimp’s, still smaller than a gorilla’s. It made slightly more sophisticated tools than chimps, using sharp stones to butcher animals.

Core from which sharp flakes have been struck off, likely by H. habilis. Olduvai Gorge, Tanzania. 

Nick Longrich, Author provided

Then came Homo habilis. For the first time, hominin brain size exceeded that of other apes. Tools – stone flakes, hammer stones, “choppers” – became much more complex. After that, around 2 million years ago, human evolution accelerated, for reasons we’re yet to understand.
Big brains

At this point, Homo erectus appeared. Erectus was taller, more like us in stature, and had large brains – several times bigger than a chimp’s brain, and up to two-thirds the size of ours. They made sophisticated tools, such as stone handaxes. This was a major technological advance. Handaxes needed skill and planning to create, and you probably had to be taught how to make one. It may have been a meta-tool – used to fashion other tools, such as spears and digging sticks.

Handaxes made by Homo erectus, from Lake Natron, Tanzania. 

Nick Longrich, Author provided

Like us, Homo erectus had small teeth. That suggests a shift from plant-based diets to eating more meat, probably from hunting.

It’s here that our evolution seems to accelerate. The big-brained Erectus soon gave rise to even larger-brained species. These highly intelligent hominins spread through Africa and Eurasia, evolving into Neanderthals, Denisovans, Homo rhodesiensis and archaic Homo sapiens. Technology became far more advanced - stone-tipped spears and firemaking appeared. Objects with no clear functionality, such as jewellery and art, also showed up over the past half-million years.

Some of these species were startlingly like us in their skeletons, and their DNA.

Homo neanderthalensis, the Neanderthals, had brains approaching ours in size, and evolved even larger brains over time until the last Neanderthals had cranial capacities comparable to a modern human’s. They might have thought of themselves, even spoke of themselves, as human.

The Neanderthal archaeological record records uniquely human behaviour, suggesting a mind resembling ours. Neanderthals were skilled, versatile hunters, exploiting everything from rabbits to rhinoceroses and woolly mammoths. They made sophisticated tools, such as throwing spears tipped with stone points. They fashioned jewellery from shells, animal teeth and eagle talons, and made cave art. And Neanderthal ears were, like ours, adapted to hear the subtleties of speech. We know they buried their dead, and probably mourned them.

There’s so much about Neanderthals we don’t know, and never will. But if they were so like us in their skeletons and their behaviour, it’s reasonable to guess they may have been like us in other ways that don’t leave a record - that they sang and danced, that they feared spirits and worshipped gods, that they wondered at the stars, told stories, laughed with friends, and loved their children. To the extent Neanderthals were like us, they must have been capable of acts of great kindness and empathy, but also cruelty, violence and deceit.

Far less is known about other species, like Denisovans, Homo rhodesiensis, and extinct sapiens, but it’s reasonable to guess from their large brains and human-looking skulls that they were also very much like us.
Love and war

I admit this sounds speculative, but for one detail. The DNA of Neanderthals, Denisovans and other hominins is found in us. We met them, and we had children together. That says a lot about how human they were.

It’s not impossible that Homo sapiens took Neanderthal women captive, or vice versa. But for Neanderthal genes to enter our populations, we had to not only mate but successfully raise children, who grew up to raise children of their own. That’s more likely to happen if these pairings resulted from voluntary intermarriage. Mixing of genes also required their hybrid descendants to become accepted into their groups – to be treated as fully human.

These arguments hold not only for the Neanderthals, I’d argue, but for other species we interbred with, including Denisovans, and unknown hominins in Africa. Which isn’t to say that encounters between our species were without prejudice, or entirely peaceful. We were probably responsible for the extinction of these species. But there must have been times we looked past our differences to find a shared humanity.

Finally, it’s telling that while we did replace these other hominins, this took time. Extinction of Neanderthals, Denisovans, and other species took hundreds of thousands of years. If Neanderthals and Denisovans were really just stupid, grunting brutes, lacking language or complex thought, it’s impossible they could have held modern humans off as long as they did.
The human edge

Why, if they were so like us, did we replace them? It’s unclear, which suggests the difference was something that doesn’t leave clear marks in fossils or stone tools. Perhaps a spark of creativity – a way with words, a knack for tools, social skills – gave us an edge. Whatever the difference was, it was subtle, or it wouldn’t have taken us so long to win out.

While we don’t know exactly what these differences were, our distinctive skull shape may offer a clue. Neanderthals had elongated crania, with massive brow ridges. Humans have a bulbous skull, shaped like a soccer ball, and lack brow ridges. Curiously, the peculiar smooth, round head of adult Homo sapiens is seen in young Neanderthals – and even baby apes. Similarly, juvenilised skulls of wild animals are found in domesticated ones, like domestic dogs: an adult dog skull resembles the skull of a wolf pup. These similarities aren’t just superficial. Dogs are behaviourally like young wolves – [less aggressive] and more playful.

Homo heidelbergensis compared with Homo Sapiens. Procy/Shuttertock

My suspicion, mostly a hunch, is that Homo sapiens’ edge might not necessarily be raw intelligence, but differences in attitude. Like dogs, we may retain juvenile behaviours, things like playfulness, openness to meeting new people, lower aggression, more creativity and curiosity. This in turn might have helped us make our societies larger, more complex, collaborative, open and innovative – which then outcompeted theirs.
But what is it?

Until now, I’ve dodged an important question, arguably the most important one. It’s all well and good to discuss how our humanity evolved – but what even is humanity? How can we study and recognise it, without defining it?

People tend to assume that there’s something that makes us fundamentally different from other animals. Most people, for example, would tend to think that it’s okay to sell, cook or eat a cow, but not to do the same to the butcher. This would be, well, inhuman. As a society, we tolerate displaying chimps and gorillas in cages but would be uncomfortable doing this to each other. Similarly, we can go to a shop and buy a puppy or a kitten, but not a baby.

The rules are different for us and them. Even die-hard animal-rights activists advocate animal rights for animals, not human rights. No one is proposing giving apes the right to vote or stand for office. We inherently see ourselves as occupying a different moral and spiritual plane. We might bury our dead pet, but we wouldn’t expect the dog’s ghost to haunt us, or to find the cat waiting in heaven.

And yet, it’s hard to find evidence for this kind of fundamental difference.

The word humanity implies taking care of and having compassion for each other, but that’s arguably a mammalian quality, not a human one. A mother cat cares for her kittens, and a dog loves his master, perhaps more than any human does. Killer whales and elephants form lifelong family bonds. Orcas grieve for their dead calves, and elephants have been seen visiting the remains of their dead companions. Emotional lives and relationships aren’t unique to us.

Perhaps it’s awareness that sets us apart. But dogs and cats certainly seem aware of us - they recognise us as individuals, as we recognise them. They understand us well enough to know how to get us to give them food, or let them out the door – or even when we’ve had a bad day, and need company. If that’s not awareness, what is?

We might point to our large brains as setting us apart, but does that make us human? Bottlenose dolphins have somewhat larger brains than we do. Elephant brains are three times the size of ours; orcas, four times; and sperm whales, five times. Brain size also varies in humans. Albert Einstein had a relatively small brain – smaller than the average Neanderthal, Denisovan, or Homo rhodesiensis – was he less human? Something other than brain size must make us human - or maybe there’s more going on in the minds of other animals, including extinct hominins, than we think.

Are cats aware? Vilvarin/Shutterstock, CC BY-SA

We could define humanity in terms of higher cognitive abilities – art, maths, music, language. This creates a curious problem because humans vary in how well we do all these things. I’m less mathematically inclined than Steven Hawking, less literary than Jane Austen, less inventive than Steve Jobs, less musical than Taylor Swift, less articulate than Martin Luther King. In these respects, am I less human than they are?

If we can’t even define it, how can we really say where it starts, and where it ends – or that we’re unique? Why do we insist on treating other species as inherently inferior, if we’re not exactly sure what makes us, us?

Neither are we necessarily the logical endpoint of human evolution. We were one of many hominin species, and yes, we won out. But it’s possible to imagine another evolutionary course, a different sequence of mutations and historical events leading to Neanderthal archaeologists studying our strange, bubble-like skulls, wondering just how human we were.

The nature of evolution means that living things don’t fit into neat categories. Species gradually change from one into another, and every individual in a species is slightly different – that makes evolutionary change possible. But that makes defining humanity hard.

We’re both unlike other animals due to natural selection, but like them because of shared ancestry; the same, yet different. And we humans are both like and unlike each other – united by common ancestry with other Homo sapiens, different due to evolution and the unique combination of genes we inherit from our families or even other species, such as Neanderthals and Denisovans.

It’s hard to classify living things in strict categories, because evolution constantly changes things, creating diverse species, and diversity within species.

And what diversity it is.

True, in some ways, our species isn’t that diverse. Homo sapiens shows less genetic diversity than your average bacterial strain; our bodies show less variation in shape than sponges, or roses, or oak trees. But in our behaviour, humanity is wildly diverse. We are hunters, farmers, mathematicians, soldiers, explorers, carpenters, criminals, artists. There are so many different ways of being human, so many different aspects to the human condition, and each of us has to define and discover what it means to be human. It is, ironically, this inability to define humanity that is one of our most human characteristics.

Author

Nicholas R. Longrich
Senior Lecturer in Paleontology and Evolutionary Biology, University of Bath

CONSERVATIVE=CONFEDERATE

The Conservatives Dreading—And Preparing for—Civil War

A faction of the right believes America has been riven into two countries. The Claremont Institute is building the intellectual architecture for whatever comes next.

Updated at 4 p.m. ET on October 5, 2021

By Emma Green

“Let me start big. The mission of the Claremont Institute is to save Western civilization,” says Ryan Williams, the organization’s president, looking at the camera, in a crisp navy suit. “We’ve always aimed high.” A trumpet blares. America’s founding documents flash across the screen. Welcome to the intellectual home of America’s Trumpist right.

As Donald Trump rose to power, the Claremont universe—which sponsors fellowships and publications, including the Claremont Review of Books and The American Mind—rose with him, publishing essays that seemed to capture why the president appealed to so many Americans and attempting to map a political philosophy onto his presidency. Williams and his cohort are on a mission to tear down and remake the right; they believe that America has been riven into two fundamentally different countries, not least because of the rise of secularism. “The Founders were pretty unanimous, with Washington leading the way, that the Constitution is really only fit for a Christian people,” Williams told me. It’s possible that violence lies ahead. “I worry about such a conflict,” Williams told me. “The Civil War was terrible. It should be the thing we try to avoid almost at all costs.”

That almost is worth noticing. “The ideal endgame would be to effect a realignment of our politics and take control of all three branches of government for a generation or two,” Williams said. Trump has left office, at least for now, but those he inspired are determined to recapture power in American politics. My conversation with Williams has been condensed and lightly edited for clarity.

Emma Green: What do you see as the threats to Western civilization?

Ryan Williams: The one we have focused on at the Claremont Institute is the progressive movement. [Progressives think that] limited government, in the Founders’ sense—checks and balances, robust federalism, a fairly fixed view of human nature and the rights attendant to it—all has to give way to a notion that rights evolve with the times.

The biggest institutional part of [the progressive movement] is this large bureaucracy or administrative state, which is insulated from control by the executive or even, increasingly, by Congress.

I would say the leading edge of progressivism now is this kind of woke, social-justice anti-racism. It’s a threat to limited government because it seems to take its lead from scholars like Ibram Kendi, who has proposed a Department of Anti-racism that would basically have carte blanche control over local and state governments. His definition of racism is any policy that results in disparate outcomes for different groups. And we take issue with that. You always have different outcomes between different groups. Human nature is varied. We all have different talents. The pursuit of equal results is only going to be successful in a new woke totalitarianism. I realize that sounds a little hyperbolic, but that seems to be the road we’re on.

Green: We’re going to unpack “woke totalitarianism” in a second, but I want to make sure I’m understanding your starting point correctly. When you say Western civilization, it sounds like you’re not necessarily describing people situated in geography or time but rather a set of ideas that you believe are falling out of fashion or are being actively destroyed by various forces in society. Am I getting you right?

Williams: You can never really divorce a set of ideas and principles from the people in which it grew up. America is an idea, but it’s not just that. It’s the people who settled it, founded it, and made it flourish.

Green: Just to ask the question directly, do you mean white people?

Williams: No, not necessarily. I mean, Western civilization happens to be where a lot of white people are, historically, but I don’t think there’s any necessary connection between the two. The ability to believe in natural rights and a regime of limited government the way the Founders did is not reserved only to white people.

Green: So you believe that there are American citizens of other backgrounds who belong in Western civilization—not just white people.

Williams: No. I think “white” is a pretty arbitrary category—

Green: People of European descent.

Williams: Okay, fair enough. No, it’s not an exclusive inheritance of that.

Green: One beef in the Claremont universe is what you all call “Conservatism, Inc.”: the professional-class conservatives who do panel discussions and run multimillion-dollar think tanks that produce white papers that ultimately don’t lead to anything, in your view. You guys are basically a think tank too. Why aren’t you just a slightly different version of Conservatism, Inc.?


Williams: Fair enough. Our target is not to say that good work doesn’t go on at the large conservative think tanks. But we think we’re in a real regime crisis right now. Our political elites and cultural and corporate institutions seem to believe in a way of doing government that is fundamentally at odds with the original, founding view—or even the view of Lincoln. We disagree on what men and women are; on what human nature is; what rights are. That’s a real crisis. We would love if our bigger brethren focused exclusively on what we think are the real threats: identity politics; this ideology of anti-racism and wokeness, which you said we’ll get to; the notion that borders are anachronistic and even racist, and that citizenship is global rather than national; that China is our main rival; the rise of big tech.

Green: Let’s talk about identity politics and being “woke.” People throw those terms around a lot, and they can obscure more than they illuminate. What do you actually mean when you say you stand against them?

Williams: There are a few strands. The most ascendant one right now seems to be critical theory, which was born in France in the ’60s and migrated to American universities. It has birthed all of these academic centers—gender studies, anti-colonialism, African American studies. It has some core tenets: There’s no such thing as truth in politics; it’s all about narratives and power, and we can’t know truth, fundamentally. There’s no such thing as natural rights; politics is making sure discrete identity groups, especially the ones who’ve been oppressed over time, now have an opportunity to express themselves.

That means deconstructing and disrupting what was the dominant narrative for a long time, which was the Founders’ regime of natural rights. One of the institutional vehicles for it was the Civil Rights Act of 1964, which was meant to fulfill the promise of the Declaration of Independence for Black Americans coming out of segregation. But the courts and administrative agencies quickly turned against the color-blind, equal-opportunity vision of the founding and toward affirmative action—this calculation of current oppressor or past oppressor, and the pursuit of equity and social justice. Now this seems to mean that we’re really not going to be where we need to be until all groups are equally represented and have the same outcomes for, say, home ownership, wealth, the proportion of CEOs, or members of Congress. That seems to be the goal of wokeism.


Green: I take it that you would not disagree with the basic spirit of the civil-rights movement, which was to disrupt the legal regime of racism enforced by the state primarily against Black Americans?

Williams: No, I don’t disagree with that.

Green: But you do disagree with how you see this manifest on the left today. Do you have an alternative vision of what racial justice or equality—or whatever term you would use—should look like in 2021? How should we address continuing, legally sanctioned discrimination, assuming you think such a thing exists?

Williams: A true regime of nondiscrimination is when the state cannot disadvantage or advantage any group based on their skin color or ethnicity. That’s the original promise of the Declaration of Independence. It is, in many ways, a color-blind Constitution.

The counter from the left is that there’s systemic racism that has built up over years by certain legal systems. I would have to see some real proof of that. The main evidence seems to be that there are disparate results, thus there’s systemic racism.

Green: Let’s take one concrete policy example. The prison system in the United States disproportionately incarcerates Black men. Reasons for this include laws around sentencing, such as three-strike rules, or the possession of certain drugs being punished more harshly than others. This is an area of policy where the left and the right disagree, fundamentally, about the role race has played in the creation of the current carceral system.


So I guess the question is, in your vision of America, is this a problem? And is it a problem caused by racism?

Williams: It would depend on what is driving the disparate results. We would have to separate out the extent to which sentencing is truly discriminatory—and it ought not to be, if it is—and the extent to which the high incarceration rate of Black Americans is due to their much higher propensity to commit violent crime.

Until we can talk about that—if we can acknowledge that on the left and the right—it would be a wonderful starting point to try to dig into some of the issues you’re talking about, like the different classification of drugs being more associated with one group or another. We have to start, though, with the acknowledgment that a lot more Blacks are in prison because they commit violent crimes at a much higher rate [than Americans of other races]. Whites commit violent crime at a much higher rate than Asians do, so I don’t mean to suggest a racial crime hierarchy. But it’s just a fact we have to acknowledge.

Green: But certain crimes are more likely to be seen by the state, right? It’s easier to enforce against petty theft than white-collar crime. The other thing you might say is, okay, there are poor Black communities where more crime happens, but there are reasons why that’s happening: Those communities have been systematically neglected over time. And we as a society should change that.

I’m pressing you on this because it seems like the people in your orbit spend lots of time opposing the progressive program, but I don’t see you articulating a vision of how to appropriately right these kinds of wrongs.


Williams: To the extent that we can discover real discrimination, solely on the basis of race, we ought to. But we need to reject the notion that different outcomes are de facto evidence of discrimination. There are plenty of examples of poverty, even acute poverty, not leading to crime. I think it has a lot to do with culture, family, and all the rest. I want us to be honest social scientists about the pathologies plaguing America.

Green: Glenn Ellmers wrote an essay for The American Mind about why the Claremont Institute isn’t conservative. One of the things he writes is that some people residing in the United States—“certainly more than half”—are not Americans in any recognizable sense.

What does it mean to declare that more than half of the people residing in the country are not truly American?

Williams: Glenn was, of course, being provocative and polemical. But if Claremont thinks real Americanism is a belief in the principles of the American founding, we have to acknowledge that a good portion of our fellow citizens don’t agree with our principles and conclusions about what politics is for. If we differ on those fundamental things, we’re really two Americas.

Even during the Civil War—I think we’re more divided now than we were then. As Lincoln said, we all prayed to the same God. We all believed in the same Constitution. We just differed over the question of slavery.

Green: This picture you’re painting of unity around a certain set of ideas, principles, and beliefs about the nature of man and God doesn’t feel accurate to the founding conditions of the United States. America was founded as a place where people who had really out-there ideas could come and live peaceably in geographic proximity to one another, eventually governed under a shared constitution. Lots of religious radicals were involved. America was founded on the principle that people needed to tolerate one another, but no more.


How is that different from today, when we are continuing to experience turmoil over who we are and what we believe and what our orientation as a nation should be?

Williams: Well, most of the Founders of America were Christians. There were radicals, to be sure. But there was much more consensus back then on what human nature is—on monotheism, broadly speaking, but really Christianity as well.

Of course, Maryland was a bunch of Catholics who wanted their own place. But there was much more consensus on what government ought to do: to secure the blessings of liberty and natural rights. First among them was freedom of conscience—your freedom to worship as you see fit. I would reject your assertion that pluralism ruled the day in the founding. Pluralism is a term that comes up much later in the American tradition, meaning that the regime is indifferent to the types of groups that are in the country. I don’t think the Founders would have maintained that at all. They thought natural rights were the possession of human beings across the globe, but the conditions for securing good government and protecting those rights were often unavailable. It took a certain bit of luck and civilizational tradition and learning and philosophy to get there.

In many ways, the miracle of America was to solve the problem that had plagued Western Europe for so many years, which was that every religious difference was an existential political difference that led to civil war and misery and depredation. With Madison and Jefferson leading the way, we solved the political-theological problem—that’s the fancy term from Leo Strauss. They solved it well enough that we could all live together as fellow citizens.


That consensus was around for quite a while—broadly speaking, constitutionalism and limited government. We disputed over those things, but everyone thought the Constitution was a good thing and that government ought to protect rights. The glaring problem that plagued us for many years was the obvious contradiction of slavery to the principles of the Declaration. But there weren’t really any Founders who defended slavery as a good thing. Maybe a few from South Carolina, but that was about it. There was a moral consensus, even if they lived up to it imperfectly, embodied in our constitutional culture. We’ve lost that. If we disagree that human biology is a good guide to male- and femaleness, we’re a long way from the consensus of the founding.

Green: Do you think America can hang together in 2021 without Christianity at its core?

Williams: I’m ambivalent about that question. I think it would be bad for America if that longtime Christian core disintegrated. The Founders were pretty unanimous, with Washington leading the way, that the Constitution is really only fit for a Christian people.

I would modify that a bit and say a majority Christian people could maintain that. But if you don’t think your rights ultimately come from a Creator, you’re halfway down the road to our modern confusion.

Green: Writing in the Claremont universe often has a dire tone to it. The essay “The Flight 93 Election” is one example of this, or that Glenn Ellmers essay.

The thing I always wonder is: What’s the end game? If you truly have a sense that the American project is in crisis; that our country is not one but two entities; and that what’s at stake is nothing less than our ability to be a free people governed under a shared constitution—are you guys, like, stockpiling weapons?

Williams: The ideal endgame would be to effect a realignment of our politics and take control of all three branches of government for a generation or two. The goal would not be the reconquest of blue America but rather the restoration of the constitutional regime that we think has been lost.

We have to find some modus vivendi to go forward. If we’re two Americas, one of the more perfect solutions might be the return of federalism—the feds laying off in many respects. Let red America be red and blue America be blue. It’s obviously more complicated than that, because even in red states you have plenty of Democrats, and vice versa. But we need to restore a robust federalism, one that allows states much more leeway. We’ve gone much too far into the realm of federal control, arbitrariness, and overreach.

Green: Republicans have lost the popular vote in nearly every presidential election in the last three decades. Do you worry about a project of minority rule—trying to assert your vision upon a country where many, many people do not agree with even your basic premises about what the American republic should look like?

Williams: I reject the premise that just because the popular vote isn’t won, you don’t possess a constitutional majority. We have an Electoral College system for a reason. Democracy, for the Founders, was a means to the end of the protection of rights. They set up a republic, not a democracy. The rule of pure numbers was never the touchstone of justice for the Founders. But the persistent inability of the right to win popular majorities—that is a problem. Ours is a project of persuading our fellow citizens, even independents and Democrats, that the current regime is on the wrong track.

Green: As a descriptive matter, do you think you guys are actually speaking for a silent majority in America that’s actually sympathetic to your goals?

Williams: That’s a testable proposition. I hope so. Trump showed the way it could be done. That was just the beginning.

Green: Many on the right seem to no longer believe in reality. QAnon gets a lot of hype, but many people on the right promote stories and narratives that aren’t supported by evidence or facts, especially about the 2020 election.

Are you at all preoccupied with this problem? I’ve noticed, for example, that one of your Publius fellows this year is a legislative assistant for Marjorie Taylor Greene, whose views certainly do not line up with reality. Does that concern you at all?

Williams: We believe in truth and reason. The question is whose truth and whose reason. That’s part of the contested quality of our national politics. And it’s not just the right. A third of the country thinks the election was given to Biden fraudulently. That includes a lot of Democrats.

Our national standard at the elite-media level these days seems to be something far from the truth. We’re no Q fans at Claremont. But it should not be surprising that, in our ideologically divided times, we have real division over truth and reality. Our national elites, and especially media elites, seem to be an ideological wing of left America rather than neutral arbiters of truth. It shouldn’t be a surprise that a good portion of the disaffected right turns to alternative sources for their political information. Many of those sources are cranks and lunatics, but that’s also nothing new. We’ve always had a robust tradition of firebrands and conspiracy theorists. It’s very American, in a way.

Green: Your answer is strikingly postmodern: You seem to be elevating the existence of multiple narratives, which may or may not hold elements of the truth. It’s also mostly a critique of the other side—a lot of people hate the media and think they don’t say true things. But if you’re trying to articulate what truth is as it relates to the American founding and ethos and mission, I would think you would be singularly concerned with the affairs in your own house. Greene has said she doesn’t think 9/11 happened. She thinks the Rothschilds started wildfires using giant space lasers. We are in a fraught time for coming to a shared consensus about what reality is. Are you doing your part to keep your house clean?

Williams: On the MTG question, it’s always been part of our project to educate folks who work in national politics, policy, journalism, etc. So I don’t think it’s suspect in the least for us to improve the staff of Congress, no matter who the congressperson is. Of course we’re concerned in policing our own house and making sure that there are not, in our political and intellectual coalition, people who reject fundamentally what we think is right. That battle is ongoing.

But I will contest what you said. I didn’t mean to elevate the notion of competing narratives. People are increasingly unsure of where to get valid information. A huge contributor to that has been our elite media.

Green: Do you feel like there is a hopeful future for America, or do you think we are headed toward some sort of generationally defining conflict that could potentially be violent?

Williams: I worry about such a conflict. The Civil War was terrible. It should be the thing we try to avoid almost at all costs.

A lot of normal Americans just want to go about their daily lives, raise their families, and make sure that our kids are successful. It’s really not that ideological, ultimately. I place a huge amount of hope in that. At the national level—the elite level—we have to advance intellectual ideas that we think are true, and the politics that we think will be the most successful. But we underestimate the extent to which we can lower the temperature in America and move forward with a lot more unity.

Green: I’ll look for that the next time I read the Claremont Review of Books—that effort to make sure our temperatures are lowered.

This piece originally stated that Republicans have not won the popular vote in a presidential election in several decades. In fact, George W. Bush won the popular vote in 2004.

Emma Green is a staff writer at ​The Atlantic, where she covers politics, policy, and religion.