In ancient footprints, a question of caregiving
Fossils at White Sands National Park show a toddler being carried across wet ground, on an urgent journey. They tell a remarkable story. But, which one?
Geologist Matthew Bennett phoned his wife, Sally Reynolds, in September 2017 with news. He and a team at White Sands National Park in New Mexico had uncovered a trail of ancient footprints, showing a young person walking quickly across a muddy landscape and then back again. Here and there beside the outgoing track, tiny fossilized footprints appear, a toddler set down momentarily along the way.
Reynolds, it turned out, had news of her own. A paleontologist herself, she had stayed back at their home in England because she was pregnant with the couple’s first child together. She’d just had an ultrasound and was told she was having a girl. They would name the child Zoë.
The two discoveries became connected.
“In our mind, it’s always been Zoë’s Trail,” Reynolds said, of the White Sands double trackway.
In Reynolds’ mind, the person carrying this ancient Zoë has always been a mother.
The footprints are an incredible story of caregiving, preserved over perhaps 12,000 years or more. It’s impossible to read about them and not be caught up in the drama they capture.
For me, it’s also been impossible not to see in them a story about how science shapes our understanding of ourselves. How our cultural narratives shape the science.
It’s a story about how we so often look to scientists for answers and affirmation, when what they really offer us—what they should offer us—is better questions and an invitation, as psychologist
wrote recently in The New York Times, to learn “to hold everything loosely.”
The footprints mark an urgent journey, at a pace just shy of a jog, bare feet sometimes slipping on the wet ground. They travel in a straight line for more than 1.5 kilometers, at one end disappearing under a fence dividing the park from the Army’s White Sands Missile Range. They stop every so often where the child’s steps appear, perhaps just long enough for the carrier to make an adjustment before setting off again.
Behind them, a giant sloth briefly follows the humans’ scent and then retreats. A mammoth crosses over, seemingly ignorant of their presence.
A few hours later—the ground a bit drier now—the track doubles back along the same path. The pace is just slightly slower and more even. While the researchers can’t say for sure, it seems as if the person is now alone. There are no corresponding toddler prints, and an asymmetry present in the outgoing steps, perhaps from added weight on one hip, is missing.
When the researchers, including Bennett and Reynolds, published their findings in Quaternary Science Reviews in December 2020, they took care not to assign a gender or a title to the carrier, the size of the footsteps suggesting an adolescent of undetermined gender or a young woman. The same was true for the New York Times article about their work.
When I first read that article, I was deep in reporting Mother Brain, and I was thinking a lot about the people who help raise babies they did not birth. Who have always helped. I noticed how neither the researchers nor science journalist Katherine Kornei even used the word “mother.” There was no automatic assumption.
It felt like a tiny opening in an otherwise rigid narrative about how things have always been. About who carries the baby, who single-handedly manages their safety and security across wild terrain.
But there it was, in the Times, nine months later.
Carl Zimmer wrote about a new paper out of White Sands and summarized the discoveries researchers had made there to date, including one track showing “a mother setting her baby down on the ground.”
Zimmer, in an email, told me that detail had come from Reynolds.
Reynolds has worked with bones through much of her career. “Footprints tell us much more colorful stories about life,” she said, when I spoke with her by phone this summer.
They capture behavior—how a person or an animal interacts with the landscape, with other creatures and with each other. Elsewhere in White Sands, there’s evidence of children jumping and splashing in a puddle formed inside of a mammoth’s footprint.
“These snapshots—we call them postcards from the past,” Reynolds said. “There are moments of fun. There are moments of pleasure. There are moments of fear. And there are moments of stress and worry.”
This trek across the playa with a child in arms may fit in the darker end of that range of experiences, Reynolds said. This was no meandering walk. It does not fit with foraging behavior. It does not suggest play.
“This person was on a mission,” she said, “and that mission probably had something to do with the child.”
It is easy to feel myself into this person’s place. I know how the weight of a child is compounded by anxiety. I can feel the excruciating effort of whispering soothing words in a child’s ear while the sea roils in one’s own mind, willing calm into being.
It is easy, logical even, to let this story become one of a mother protecting her infant—an ancient “mama bear.” White Sands commissioned artist Karen Carr to create a series of paintings documenting the footprint discoveries there. In one, above, a woman clutches a child to her chest, her body a shield against the elements as bolts of lightning split the dark sky.
Science, Reynolds told me, “demands rigor.” It also ignites imagination.
“People can relate to the idea of having your arms half falling off because you are carrying a child who is tired and whiny,” she said. “I’m aware that there is a tension around getting it right as a scientist. But, in explaining it to people, is it wrong to humanize the story so that it makes the story more relatable?”
Storytelling is an important tool in science communication. Paleontologist Kevin Padian has written eloquently about the need for richer storytelling by scientists, and not only the dry, prescriptive “anti-narrative” that is the standard of peer-reviewed journals.
Stories about the quest of science, the people who engage in it, and the importance and context of the findings themselves help public and private funders decide where to direct their money, Padian explains. They inspire students. And they show the general public the value of science itself, at a time when that is increasingly questioned.
“Narrative is not only natural but necessary,” he wrote.
Also important, Padian wrote, is the capacity for scientists to ask, “How will I know if I’m wrong?” In that way, he says, the stories of science are “constantly developing.”
We can see that development, for example, in a recent analysis that challenged the cultural narrative that men have always been hunters and women always gatherers, men natural competitors and women natural caregivers. That belief was grounded, in part, in the study of ancient populations and modern foraging societies.
But when researchers at Seattle Pacific University looked at the records of observations made of dozens of foraging societies, they confirmed what some scientists have been saying for decades: The story was wrong.
They found evidence of women hunting in 79 percent of the societies for which they reviewed data—evidence that had long been disregarded by researchers who simply could not imagine women playing a significant role as hunters. The story changes.
But what are the consequences of getting it wrong? And for so long?
“Next to the myth that God made a woman from man’s rib to be his helper, the myth that man is the hunter and woman is the gatherer is probably the second most enduring myth that naturalizes the inferiority of women,” historian Kimberly Hamlin told NPR.
Storytelling itself does not threaten the rigor of science. I think the threat comes as those stories are told over and over, simplified and codified by time. The accountability required by Padian’s question—“how will I know if I’m wrong?”—lost to distance. The story itself becomes fact.
What’s the harm in thinking it’s a mother on that stormy playa carrying her child home to safety? It’s a beautiful story. And, truly, my only problem with it is what it may leave out.
If the researchers’ suggestion is correct, the mother—let’s assume—returns alone. Why? Where has she left her baby and with whom? Where is she returning to, and what’s there for her on the other side?
“In my mind, it’s always been a rather anxious journey—both ways,” Reynolds told me.
Was the child sick, and the mother seeking out someone who could help, and then returning to care for others? Or was she delivering the child to a trusted helper while she turned her attention to a separate crisis?
There are lots of other possibilities—maybe the mother has died, and someone is delivering this child to relatives who will care for her—but nearly any scenario that could explain the fossilized footprints suggests that multiple people have assumed responsibility for the child’s care, even temporarily.
Human mothers have always negotiated the many demands on their time and attention, from multiple children and from all that’s required to provide for their families and to take care of themselves. They have always required help to do it.
The simpler narrative—mother protects baby—misses that.
Maybe I’m nitpicking. But I’m weary of the distilled story of human caregiving that presents mothers as sole arbiters of a child’s well-being. The one that props up opposition to the things modern parents need to manage the conflicting demands inherent to parenting, including paid leave and affordable child care. And I can’t stop noticing all the ways, across society, that we retell this story, over and over, because it’s the one we’ve heard before.
We miss so much if we look at childrearing only through that frame, Stacy Rosenbaum, assistant professor of anthropology at the University of Michigan, told me.
Rosenbaum studies caregiving among primates, including in humans and gorillas, with a focus on paternal care. She discusses the White Sands work in a course she teaches on human evolution and, like me, she is interested in what was happening on either end of this double trackway.
Cooperative caregiving, she told me, “is such an important part of the human story. We think that this is incredibly integral to why humans are the way they are and the unique features of our life history. Any time you can see this behavioral evidence of it—that’s an amazing thing.”
Much of Rosenbaum’s work has raised new questions in places where we’ve long imagined answers. In a recent paper on the evolution of paternal care and breeding bonds (shared here), she and colleague Joan B. Silk argue that doing good science often requires “increasing uncertainty.”
Scientific publishing, Rosenbaum told me, favors a straightforward narrative. “It’s the things that don’t fit and the things that we can’t—we don’t yet know how to explain—to me, those are the most interesting parts,” she said.
It’s a point my conversation with Reynolds ultimately came to, as well.
“We’ll never get to anything that will count as truth, the one single, accurate version of the event,” Reynolds said. “So I suppose the real story becomes how we have to tolerate this element of uncertainty, and how that sort of gives us the space to impose our individual experience on it.”
That story—of the uncertainty and all that space might contain—is worth repeating.
This is fabulous! When I visit there I interpret them as a sisters. Thank you for all of this work fleshing this problem out.