The histories of Indigenous peoples of the Americas are fascinating. Looking at the spectacular buildings of Machu Picchu, the walrus ivory carvings of the Canadian Arctic, and the effigy stone pipes of the Eastern Woodlands, and considering the extraordinary diversity of past and present Indigenous cultures, many people wonder at their origins.

How did the First Peoples survive the ice age and arrive on the continents? How did they adapt to the new environments in these lands?  Did they arrive 15,000 years ago, or 30,000 years ago? Where did their ancestors come from? How did they travel beyond the massive ice sheets that covered the northern portions of the continents during the Last Glacial Maximum? Indigenous peoples themselves have diverse and ancient histories of their own ancestors, some of which align with archaeological and genetic models of the past, and some of which do not.  A thousand questions drive legitimate and respectful conversations about the past.

In recent years, “alternative historians” have exploited this thirst to learn. Self-appointed “experts” or journalists such as Graham Hancock variously claim that the first people to enter the Americas were: from Europe, from sub-Saharan Africa, from Egypt  (some claim there’s an Egyptian city in the Grand Canyon and Egyptian artifacts in Burrow’s Cave in Illinois), giants (descended from an extinct human relative known as the Denisovans), travelers from the Black Sea region, Atlantean refugees, aliens, and alien mentees. The proponents of these claims have landed shows on Netflix and the History Channel, and book contracts. Sensationalism sells, as the viewership of the latest series in the genre, Netflix’s Ancient Apocolypse, demonstrates. Profiting off their visibility from media appearances, some grifters organize conventions, and offer “informal research expeditions” to “investigate megalithic sites without bias.”

While these purveyors make millions, their theories perpetuate a harmful and incorrect view of the origins of Native Americans. They cook up pseudo-histories by cherry picking “evidence” (often faked, misunderstood, or paranormal) to support a pre-determined outcome, and by eschewing hypothesis testing, peer review, and other tools of rigorous scientific inquiry. Scientists, skeptics, and scholars have debunked these claims, pointing out factual inaccuracies, identifying faked evidence, noting anti-Indigenous rhetoric, and delving into history and context that explain why the bogus claims emerged in the first place. But a lie can go halfway around the world before experts can debunk it.

Scientists, Indigenous knowledge holders, and scholars from multiple disciplines have spent decades compiling evidence about the First Peoples of the Americas—using genetics, professional archaeology, and knowledge passed down many generations among Indigenous communities to understand the histories of Indigenous peoples. One of the most recent tools available is the study of complete genomes from ancient peoples, which has allowed scholars to produce powerful models of biological histories and test relationships between past and present populations.

DNA recovered from ancient remains shows us that the First Peoples of the Americas have ancestral roots in Asia, and that they descend from two populations who mixed during the Upper Paleolithic era: One group related to the ancestors of present-day East (with affinities to some Southeast) Asians, and another group descended from a population called Ancient North Eurasians. The East Asian and Ancient North Eurasian groups came together approximately 25,000 years ago; soon after, the DNA evidence suggests, the intermingled population became isolated for a few thousand years, coinciding with the peak of the global climactic event called the Last Glacial Maximum, also known as the ice age.

During this period, human populations across the globe retreated to locations where resources were more abundant. Based on paleoclimactic reconstructions, some archaeologists, geneticists, and paleoclimatologists hypothesize that the population ancestral to the First Peoples may have moved to the southern coast of central Beringia (the land bridge which connected East Asia and West Alaska until the Earth warmed and sea levels rose, creating the Bering Strait).

The DNA evidence suggests that the Beringian population split into several branches. One moved into the Americas as soon as routes past the glacial ice sheets became accessible, after about 17,000 years ago, and gave rise to all peoples south of Alaska. Genetics and some traditional Indigenous histories indicate that people were present in the Pacific Northwest extremely early; the first movements into the Americas were likely by boat along the coast.   There is no genetic evidence that the earliest Native Americans were Europeans, ancient Israelites, or African mariners, as pseudo-historians sometimes assert.

At human occupation sites throughout North America and South America, a vast preponderance of archaeological evidence—securely dated physical traces of human activities in undisturbed geological contexts—demonstrates that these First Peoples were making homes in North and South America by around 15,000 to 16,000 years ago, and that they had no contact with any outside group (with very limited exceptions) before 1492.

There were some exceptions to their isolation. Genetic evidence hints that there may have been brief contact between Polynesian and South American populations approximately 800 years ago. The L’Anse aux Meadows site in northern Newfoundland contains wood-framed buildings and artifacts that confirm Norse people lived there between 900 and 1,300 years ago (congruent with narratives from both Vinland Sagas and Indigenous traditional histories). Human and animal footprints at the White Sands Locality 2 site may date back between 21,000 and 23,000 years, one group of scientists has (somewhat controversially) suggested. If their data—which align with the traditional histories of Indigenous peoples in the region—hold up to additional scrutiny, it would indicate that an earlier population predated the post-ice age expansion out of Beringia. This is one of the most exciting developments in the field in recent years, and is an area of active research by multiple archaeologists and geneticists.

But such exceptions do not support “alternative history” claims, particularly that the First Peoples of the Americas were anything other than the ancestors of present-day Native Americans, or that other Europeans besides the group at L’Anse aux Meadows entered the Americas prior to 1492. No burial mounds, stone pyramids, or ancient settlements were built by Egyptians, aliens, or a “lost race.”

Scientists don’t agree on a single, unified model for the peopling of the Americas. We debate which sites contain valid evidence of a human presence, how old they may be, and their significance. That’s a good thing. Disagreeing about how to interpret the archaeological record is the strength of the scientific method, not a weakness. It creates space for rigorous scrutiny of evidence and testing of hypotheses, which leads to a gradual accumulation of knowledge and the development of more accurate models of the past. It requires a profound humility to articulate how your ideas may be tested and proven wrong.

Archaeologists, biological anthropologists, and geneticists studying the earliest histories of the First Peoples are not immune to criticism. We are grappling with legacies of racisim against Native Americans, some which continue to persist within our disciplines. All too often, non-Native scientists ignore or treat disrespectfully traditional histories and Indigenous perspectives on their own past. We can and must do better.

But “alternative historians” and pseudo-archaeologists do not even acknowledge—let alone seek to root out—the racism and anti-Indigenous perspectives that are so integral to the stories they tell. Instead of trying to test hypotheses, they build cases for their pet theories—whether by co-opting Indigenous traditional histories to support racist theories, speculating wildly over single artifacts, or even looting Indigenous sacred sites to manufacture evidence.  When scholars or institutions attempt to debunk this charlatanism, the alternative historians deride them as part of a conspiracy to suppress “the great secrets of Earth history.”

But scientists care about what is actually true; the YouTube algorithm does not. There is a special kind of joy at the intersection of our love of the past and our love of solving puzzles. It’s familiar to those of us who feel goosebumps walking amid the ruins of ancient buildings, who read every historical marker on road trips, or who delight in the fingerprints of the potter marking ancient ceramics. We want to understand these large and tiny histories, and to see what the past was really like.

Embracing the joy in learning about the past and present cultures of the Indigenous peoples of the Americas—including learning about the peoples whose lands you are on and rejecting harmful and inaccurate narratives that drive a wedge between these peoples and their own histories—is the heart of science and the soul of humanity. Respectful curiosity is the starting point for understanding the past, including just how long Indigenous peoples have been on these continents. And it can start close to home: Close your laptop, and pay a visit to an ancient site.