We came to New England from many places, by many routes, for many reasons.

No humans lived in this part of North America until after the late glacial maximum, what we call the Ice Age. Anthropologists think that as soon as tundra developed in isolated spots, replacing ice and bare rock, small bands of humans moved in, roughly 12,000 to 9,000 years ago.

That’s an eyeblink in geological time. No matter what famous names we might cite as forefathers or foremothers, we’re all newcomers.

We’re also all cousins.

The first hunters who entered New England’s gradually recovering ecosystem descended from Native American Indian tribes to the south and west. They walked here, spreading into newly available territories. Compressing the story of thousands of years before that, we can say that their ancestors had come from Africa, by way of Asia.

The Pilgrims and Puritans of early colonial Massachusetts, and all the other groups who came from various parts of Europe, are also not-so-distant descendants of people–in fact, one specific man about 60,000 years ago–in Africa. They arrived in Europe by way of the Middle East and the Mediterranean, or more often by way of Asia. They came to North America much later, by boat, and later by airplane.

African slaves came from Africa more directly, and earlier than most European Americans, transported by boats and brutal force.

Still more recent immigrants from Asia and Latin America and Asia and Africa came to North America and New England by choice, although often out of desperation, as political or economic refugees.

All of us, reunited cousins from all over the world, belong to a very young species that emerged only 200,000 years or so ago. Furthermore, those of us who call ourselves European Americans, Asian Americans, Native American Indians, or Latin Americans all descend from a tiny handful of people who left the African continent about 50,000 years ago, whose descendants spread across the world.

Most modern Africans are descended from the ones who stayed in Africa. They show much greater genetic diversity, not having passed through that tiny genetic gauntlet of the small group who left Africa and survived. But all of us, everywhere in the world, descend from that one man long ago. We’re cousins.

How do scientists know all this? How did I learn it, and how did my classes come to learn it?

It’s an incredibly exciting time to be alive and interested in our species and how it came to be. Like toddlers who’ve just learned to walk (or talk), full of the enthusiasm of new powers of inquiry, scientists are busily synthesizing the discoveries of multiple fields, including physical anthropology, archaeology, linguistics, and genetics. In the process they’re coming up with new answers to the questions, ‟How did we get here?” and ‟Who are we?”

Spencer Wells, an American geneticist, helped some of this knowledge reach ordinary people like me, by writing a book meant for us, and at the same time working with a British filmmaker to create a video. There’s some pretty complex science in the video, particularly the sections about genetics. I read and reread the book, and some other books, in order to understand it more fully. Still, when I watched the video (and rewatched, and rewatched again) I thought, ‟What else could matter more than this, for 11 and 12 year old students who are trying to understand themselves and the world?”

Knowing the ambition and eagerness of my students, I predicted accurately that they would become deeply engaged in the video, and be able to understand large parts of it–so long as I prepared adequately. I got to know the video very well myself, and thought carefully about how to divide it into digestible portions of no more than 20 minutes or so.

Some bits we watched more than once. We talked about it all a lot, asking questions and helping each other understand, never rushing. The book’s photographic portraits of people from all over the world helped us have a sense of real people behind the science.

From the portraits section of The Journey of Man, these are people from Canyon de Chelly in Arizona, north central Mexico, Poland, New Mexico, Tanzania, Kenya, and Japan

We also did a lot in class, hands-on, to make it as real as possible for all of us.

For example, one year we made big brown paper continents to spread out on the Common Room floor. With the help of maps in the book, we modeled the migrations of modern humans, complete with colorful party streamers labeled with the designations for the Y chromosome mutations that let geneticists do all this tracking. I will never forget hearing 12-year-olds talk knowledgeably and confidently about those mutation numbers, having mastered them more thoroughly than I had myself.

When Spencer Wells visited rock paintings in Australia, we turned one of our whiteboards into the wall of a cave, covered with symbols of our own identities.

Another year, the class was particularly interested in a section of the video based on Spencer Wells’s visit with the reindeer-herding Chukchi, a people in far northeastern Asia. In the video, Wells sits by a fire, chews on reindeer meat, sleeps in a yaranga through a night when the temperature dips far below zero—all in an effort to help us imagine what it took, or still takes, to live in the tundra.

Here, as throughout the video, Wells expresses his respect for the resourcefulness, resilience, and skill humans have shown in the course of settling the globe. We decided to enter that more deeply by doing additional research about the Chukchi, and writing and illustrating our own picture book about them.

In more recent years, we’ve used a BBC video series, The Incredible Human Journey, which follows Alice Roberts, a British medical doctor, anatomist, and anthropologist, as she travels from continent to continent searching for evidence and meeting with scientists from many disciplines, to understand the history of our own species, modern humans.

She goes stalking with highly skilled San trackers in Namibia, and measures their body temperature as they run for hours in pursuit. She watches Lapp women use sinew to sew clothing from furs, an ancient skill essential for life outside the tropics. She works with Chinese experimental archaeoligists trying out possible early methods for making clay pots.

She crosses from one Indonesian island to another on a bamboo raft built entirely with technology that would have been available to ancient people.  She considers the evidence of ancient human occupation on an island off California that could only have been reached by boat, providing support for the theory that many of the earliest North Americans paddled here, around the coastline.

It’s a five hour series. Each time I used it with a class I could only show parts. Mostly I used it to support our work on the history of technology–and if you read back through that list I think you’ll see why. Once I’d shown one section, the kids would watch me setting up to show a video and ask hopefully, ‟Is it Alice?”

Alice Roberts now holds a very special appointment at the University of Birmingham, in England, as a professor of Public Engagement in Science. In a recent video interview, she talked about the importance of science to our modern survival as a species, and the importance of scientists reaching out to the general public—as she herself has done. She also writes unusually readable pieces about human evolution for the Guardian, including a fascinating piece about recent evidence that modern Europeans carry traces of Neanderthal DNA.

In The Incredible Human Journey, Alice Roberts talks about ‟bones, stones, and genes”—her way of summarizing the diverse sources of evidence on which she most focuses. Throughout the video, she shares her own point of view as an anatomist and physical anthropologist, speculating, reflecting, celebrating.

At the end of the series, though, Roberts speaks as an ordinary human heart, sharing the sorrow I feel myself, about the terrible calamity of what happened when European Americans traveled to Africa and North and South America. ‟We didn’t recognize each other,” she says, in poignant understatement.

Europeans saw dark skin as a sign of savagery, not as a functional natural sunscreen that pale Europeans suffer without. (But the ancestors of northern Europeans had to lose that melanin protection in order to get enough sunlight for the manufacture of vitamin D, in places where it’s rarely okay to be mostly bare.)

All unaware, we were cousins, which makes the devastating cruelty and loss of life that attended our reunion even more heartbreaking.

Like Alice Roberts, Spencer Wells also hoped that his video would change us, modern humans, by showing us how closely we are all connected. He hoped that it would be illuminating for us to know that we are all Africans, and to know how close we may have come, as a species, to dying out, as other hominid species did.

For both Wells and Roberts, our species’ past is sobering but also inspiring. Exploring their story with kids, I’ve known both emotions.

So I’d like to know: For past students who explored the history of our species with me and with other teachers, how has that touched you? Were we right in thinking that few ways of looking at the world could be more important to share?

And for other adults who’ve been like me, spellbound amateur riders on this pretty amazing scientific train, how has it changed you?