The Mother(hood) of Invention

To send Women’s History Month out in style and to unabashedly advertise the upcoming A-Z blogging challenge of April, this post will honor the role played in women in early invention–very early, in fact. I want to focus on a major invention that contributed to the evolution of our entire species: the baby sling.

I’ll give you a sneak preview of my A to Z plans for April at the end of this discussion. As a hint, we’re going wa-a-a-ay back in history, in some cases, to before there was history because humans hadn’t invented writing yet. Today, I want to consider the sling and ask: How did this invention set up the evolution of humanity itself? Why was it so important? And what other aspects of evolution and invention followed as a consequence?

I was inspired to write this after rereading the excellent book on early humans, Who Ate the First Oyster?, by Cody Cassidy. I’ve written about the book before, and I was intrigued that its first chapter makes a pretty bold statement: a woman invented the very first invention. Cassidy argues convincingly that an early protohuman called Australopithecus fashioned a baby sling, and that it changed everything. Let’s see how Cassidy gets there.

The First to Belong to the Human Family

We can’t go much further without a little Zoology and Anthropology, but I’ll keep it very simple. Start with mammals and primates. Between 65 million years ago (mya), after the dinosaurs died off and 7 mya when the Family of Humanity (hominidae) emerged, mammals flourished and diversified. (Of course, mentioning dinosaurs is obligatory!) One variation of mammals was the group primates, i.e. monkeys and apes. Like other mammals, apes had fur, gave milk, were warm-blooded, and produced live births. Also, like many but not all mammals, they lived in trees and walked on all fours.

Unlike other mammals, though, primates had individual digits on fingers and toes, birthed only one baby at a time, and sported big brains. While apes are not as smart as humans, clearly, they are still pretty smart. Chimpanzees know how to strip sticks as digging tools, and apes have been able to learn simple sign language and even to use matches.

Roughly 3-7 mya, a new type of primate branched off from the others. The famous discovery of the “Lucy” skeleton in Ethiopia showed that as early as 3 million years ago, one type of primate had developed changes to their pelvis and legs that allowed them to walk upright. Lucy was about 3 feet tall, female, and distinctly bipedal, although she was ape-like in brain size and other ways. She was designated as Australopithecus afarensis, a group on a new branch of primates designated as hominids, i.e. the Family of Humanity. Even so, given Lucy’s long arms and small size, she probably still slept in trees, probably still had fur, and probably ate mostly fruits, insects, and the occasional scavenged bit of meat.

Becoming bipedal comes with advantages and disadvantages. You can spot predators and food better, cool off from the hot ground, and use hands and feet for different purposes. On the other hand, bipedalism makes you slower and easier to spot by big predators; hence, the still-sleeping-in-trees part. And one more thing. If your babies cling to your back when you walk around upright, they’re more likely to fall off.

What Happens If Mom Knots a Few Vines?

Cassidy and many scientists argue that the bipedal Australopithecus created baby slings. To be sure, archaeologists have never found any such slings preserved near A. afarensis remains. They would have been made from vines and leaves, and organic material would not last millions of years. Plus, as Nancy Tanner and Adrienne Zilhman put it in “Women and Evolution”: Behavior does not fossilize. But Tanner and Zilhman note that chimps carry things often, using folds in their body, or occasionally a leaf. Apes can tie knots. They remember what they learn, and they teach others what they know. Given four million years to play around with tools, a few knotted vines and a leaf could be improved to a sling.

We don’t know if Australopithecus mothers made slings. But what happens if they did? Their babies would be less likely to fall off as they move around. That makes it possible for moms to become bipedal. It also means that mom doesn’t need to have fur for the babies to grip. And, most significantly, it means the babies can be carried around longer, which means that they don’t have to gestate as long.

Human babies are among the most helpless infants on the planet. Colts pop out and run off. Only a few weeks after being born blind and toothless, many cubs are pouncing and biting. In comparison, human babies are chubby, can’t walk, can only eat one thing, and have big heads that have to be supported. Just in order to fit into the birth canal–and I use the term “fit” loosely–humans babies have to come out much earlier in the gestation cycle than other animals. Lots of studies argue that their inherent “cuteness” triggers a protectiveness instinct in adults. If those hominid babies are going to come out so helpless, their parents better have a way of caring for them over the months and years before they become adults.

Which Came First: Bipedalism, Hair, Big Brains, or the Sling?

After Australopithecus, around 1-2 mya, a new hominid named Homo habilis emerged. They called him “handy man,” because such skeletons have been found with stone cutters and other tools. I am oversimplifying; there are other species of Homo discovered in the last few decades that complicate the picture. Still, regardless of where H. habilis and his cousins fit in the evolutionary timeline, he looked a lot different from Lucy. The Handyman was much taller with a braincase nearly twice as big.

In other words, while we don’t know if Lucy’s “people” really developed baby slings, something allowed them to stand fully upright, move out of the jungle and on to savannahs and other habitats, and have even bigger heads. They no longer slept in trees but probably on the ground. They likely lost a lot of their fur and developed hair, which is a far better regulator of temperature. That allows humans to be mobile and to live in a variety of habitats. Big heads would be much harder to birth unless the babies continue to come out early and helpless, requiring care for a long time. Without the sling, none of this seems possible.

Catching Fire

If the baby sling both created and was needed for the evolution to bipedalism, then a similar set of logic would set up the next big human invention. Around 1-2 mya ago, humans started to control fire. Fire already existed, and humans or others could have opportunistically carried some from a lightning strike, and learned to use it, even to feed it. However, the big trick was how to start it. That required knowledge of gathering and breaking rocks which contain pyrite.

There’s big debate in the anthropology/archaeology community about when control of fire started, whether this circle in a 2 mya burial ground is a fire pit, or whether that bit of charcoal was human-made or a random charred log. But there were big differences in the skeletal structure of the next hominid in the chain–Homo erectus–compared with Australopithecus and Homo habilis. Shorter arms, longer legs, bigger brains, yes. However, one of the biggest changes appeared was in their digestive system.

Homo erectus didn’t have the teeth to chew raw food or the stomach capacity to digest it. Scientists know that hominids by 2 mya ago had moved from a diet of primarily fruits and insects to one that had a fair amount of meat. Chewing and digesting it would have taken most of the day for early primates. It would be a big evolutionary advantage if the food were cooked. Cooked food needed smaller teeth and a smaller digestive system. The skeleton of Homo erectus suggests that hominids had mastered fire, even if the burial pits couldn’t prove it.

Our inventions aren’t the result of our evolution, [archaeologists] believe, but are instead the explanation for the route it took.

Cody Cassidy, “Who Invented Inventions?”

If you have a sling, then you can be bipedal, have helpless babies whose brains are bigger, and move to habitats outside of trees and jungle. Those bigger brains broaden your use of tools to stones, sharpened sticks, and fire starters. Fire lets you ward off predators while you are sleeping on the ground. Fire keeps the weaker members of the group–women and children–safe if the stronger members go off to hunt game. Fire cooks food, whether large animals brought in by hunters or fish and small animals brought by the gatherers.

Fire lets you live in colder climates, like all of Europe, lets you paint caves, and ultimately sit around to tell stories. Like this one.

A commercial for Ivory soap in the 1950s shames a woman who dares to carry around her baby in a sling, “like an Indian.” Instead, she is encouraged to put the baby into a little plastic chair. But that wouldn’t have worked for Lucy. Moms who put their babies down 5 million years ago would have seen them carried off pretty quickly.

Good thing that they used slings instead! Otherwise, we never would have walked around, lost our fur, and developed the brains to create videos which we then criticize.

Thanks, Australopithecus! Thanks Lucy!

And thanks Women’s History Month, which I will continue to champion, despite the current fad of pretending that diverse contributions to culture should not be highlighted.

Sneak Preview: A to Z

If you’ve seen my posts before, you know that I am an enthusiastic participant in the April A to Z challenge. This was a challenge started by a few bloggers in 2010 (15th anniversary hurray!) to write 26 posts, one a day for most of the month, following the alphabet. I’ve covered, in order, the Olympics, Accounting, the Renaissance, the Silk Road, and Dinosaurs. In doing so, I found I covered enough ground to create full-length books with some judicious addition of pictures and supplementary material: The A to Z Olympics (2021) and The A to Z of Dinosaurs (2024). So I look forward to the challenge!

My history studies focused on medieval history, but I’m also a fan of ancient history and now prehistory as well. Inspired by authors like Cody Cassidy and Jared Diamond and carrying a fervent desire to explore the development of civilization worldwide, my 2025 topic is:

The A to Z of Ancient Inventions

I’m going to cover early inventions from roughly 300,000 years ago up to around 500 CE. I’m not primarily interested in who did it first, but where and when was it invented, and how often was it re-invented around the world. Plus, how do we know?

I’ll delve into this in more detail on Monday March 31st, then start April 1st with A is for… well, you’ll have to guess that one! I hope you’ll join me.