Just a short drive outside of Johannesburg, unassuming tracts of farmland and rolling hills hide the scientific garden of eden. Here, an area of just 180-square miles has produced some of the oldest hominid fossils ever found. More than 40% of human ancestor fossils found in the world have been unearthed here, and they have provided vital clues in piecing together the story of where humans came from. It was from this sites that science was able to determine that all of humanity came to be in Africa. The scientific discoveries made here, some as old as 3.5 million years, and the discoveries that continue to be made in the area, are why Cradle of Humankind is included as part of one of South Africa’s eight UNESCO world heritage sites.
Our visit of the Cradle began at the Maropeng Visitor Center. A tour of the center begins on an indoor boat ride, a “ride through time,” that weaves through waterfalls, snows storms, and volcanoes. The museum beyond provides a broad overview of the evolution of humankind and the significance of the site. Full of bright explanations and interactive exhibits, it’s a good visit for kids but left us adults wishing for a little more detail.
From there, we headed to the nearby Sterkfontein Caves, where some of the first and most important discoveries in the area were made. Outfitted with hard-hats, we followed our guide down a steep flight of stairs into the earth.
The story of the caves began in the 1890s, when limestone miners stumbled upon tiny, human-like fossils and brought them to the attention of archeologists. In the first half of the 20th century, Professors Raymond Dart and Dr. Robert Broom from the University of the Witwatersrand conducted excavations, uncovering some very important fossils that supported the theory that these human-like creatures were the ancestors of the modern human. Contrary to popular understanding, human evolution does not mean that people evolved from apes. Instead, humans and apes both evolved from a common ancestor. These fossils also shared this ancestor, and their bones provide clues into how humans came to be.
The caves continue to reveal secrets. The fossils came to be in the caves by sheer accident. Early human ancestors did not live in the caves. They lived in the grasslands above. But due to their small stature, they could hardly see through the tall grass in front of their own faces, which led to a few unlucky ones falling into the cave openings to their death below. Over time, rain washed mud, other bodies, and debris into the hole, covering the bones and eventually hardening into a rock, called breccia.
In 1997, archeologists discovered a near-full skeleton of a Australopithecus, the first find of its kind. The first part of the skeleton to be found were the tiny foot bones, giving the skeleton the name “Little Foot,” and it is believed to date to over 2 million years ago. Due to the painstakingly slow process of extracting fossils from breccia, Little Foot is still being excavated, 29 years later.
The part of the cave we saw was cavernous, but only a small part of the cave has been explored. The majority is concealed by a largely unexplored underground lake system that spreads out for an unknown distance. An attempt in the 1980s to map the underground depths resulted in the death of diver, so the full extent of the cave system remains undiscovered.
The fossils sites have been chosen as a UNESCO site not only for their scientific importance, but also for the huge future potential they have yet to reveal. It is fascinating to see how our understanding of the origins of humankind has evolved over the years, and it will be exciting to see how it continues to evolve over time as science answers, and raises, more questions about how humans came to be the incredible beings that we are.