To Our Children's Children's Children

So it's our first full day in South Africa and it's about 10:30 in the morning on a Saturday and we are standing in a cave pretty much in the pitch dark. No, it's not safari time yet; that will come in a couple of days. Because there's a risk of head-bumping (you know...due to the almost complete lack of light...), we are wearing hardhats. Our guide is standing in front of a fenced in area within the cave called the Silberberg Grotto. He's equipped with the groups's only flashlight and he's telling us about some human remains that were found in the cave in the early 1980s. The skeleton was called Little Foot and it is remarkable because it demonstrated that human ancestors could walk upright more than 2 million years ago. Cool, right? 

The Silberberg Grotto is within the Sterkfontein Caves, a limestone cave system about an hour's drive north and west of Johannesburg. The caves are a part of the multi-site Cradle of Humankind World Heritage Site celebrating South Africa's contribution to the evolving story of human evolution. Little Foot wasn't the first skeleton found in the Sterkfontein Caves. That honor belonged to a skeleton called Mrs. Ples. Mrs. Ples (who ultimately is now pretty much acknowledged to be male and not female) was discovered in 1947 and is important as one of the most perfect skulls of our species' ancestors. We saw the spot where Dr. Robert Broom discovered the skull of Mrs. Ples on the way out of the Caves.

So Sterkfontein Caves is super-significant in the study of human evolution, right? The answer to that question is unquestionably "yes".

But it may be difficult to see that on a first visit. Very difficult.

Where Little Foot was found.

Mrs. Ples is pretty much universally acknowledged as an Australopithecus africanus and the remains of her (or him) are dated at between 2.1 and 2.8 million years ago, although this number has shifted around a bit over time. The fact that there is a 700,000 year range on the actual date should tell you how precise this dating stuff is.

Little Foot was first also thought to be an Australopithecus africanus and was dated at a similar vintage as Mrs. Ples, although just like Mrs. Ples, Little Foot's actual speculated age has shifted around a bit from just a bit older than 2 million years to almost 4 million years old (the exhibit signage at Sterkfontein Caves still has the older date). 

Know what else has shifted around a bit? Little Foot's species. That skeleton is now classified as an Australopithecus prometheus, although there is some good amount of debate about that classification.

So let's get this straight...there were two different species of Australopithecus roaming around at the same time on our planet? 

Well, no, it doesn't appear that was necessarily the case. Although maybe. Or maybe yes. There may actually have been three Australopithecus species that were contemporaneous. Ever heard of Lucy? From Ethiopia? Louis Leakey? 1974? Also an Australopithecus but dated to about 3.7 million years ago and neither an africanus nor a prometheus. Lucy was an Austrolopithecus afarensis.

Which one is the ancestor of modern man (meaning Homo sapiens)? Maybe all of them. Maybe none of them. Or maybe some but not others. Maybe there was really no overlap between these different species but maybe there was. Maybe they evolved into the same or different species. The real answer is we don't know. I probably should have put a giant asterisk on that "one of the most perfect skulls of our species' ancestors" statement in the second paragraph. 

Australopithecus. Which one it is, I don't remember. In the exhibit at the Sterkfontein Caves.

What we do know is that Australopithecuses (is that the right pluralization?) walked upright and that anatomical change represented a departure from the other apes that were around on our planet at that time, and in fact may still be around. But we don't know how that happened. We lack the scientific evidence to understand how the evolution occurred on that issue. 

So we must understand how we got from one or more species of Australopithecus to Homo sapiens, right? How we evolved from upright-standing, early people with longer arms and much smaller brain cavities into the large-brained, apex predators ready to destroy the whole planet in spite of ourselves that we are today, right?

We don't. Not really. Let's come back to that.

After our couple of hours over in the Sterkfontein Caves, we visited Maropeng, which is effectively the main visitor's center for all of the Cradle of Humankind properties. The main building at Maropeng resembles some sort of giant truncated cone covered in grass at the end of a long, paved walkway. Inside the building are exhibits about the evolution of humans and the development of human society and technology. There's also some kind of weird, non-sequitur indoor water ride that communicates about zero information and is not stimulating in any way. 

There is a ton of information inside Maropeng. All that stuff about multiple species of Australopithecus wondering around southern and eastern Africa is covered in great detail. Lucy. Mrs. Ples. A possible common ancestor between modern man and modern apes found in present-day Chad that dates to 7 million or so years old. It's all in there along with images and fossil records and all sorts of other things. Although Little Foot as a prometheus is pretty much absent. That last part may be because the information keeps shifting around a bit or a lot. 

What else is in Maropeng? All sorts of stuff. Need a timeline of human development alongside a record of the appearance and disappearance of different species? Want to know when the domestication of dogs or cattle occurred relative to the appearance of the wooly mammoth or more recent human ancestors (like Homo Erectus)? Then Maropeng is the place to be. Want a depressing account of the future of fresh water on our planet? Also inside Maropeng.

That last one by the way is chilling. Global consumption of fresh water is doubling every 20 years. There's only so much of this stuff to go around and humans won't stop breeding. We visited two Mayan sites earlier this year where the populations exhausted the planet's local ability to support their growing ranks. That sort of thing is coming on a much larger scale sometime later this century or next century and it's not going to be pleasant when we start running out of water to drink.

So we've got Mrs. Ples and Little Foot and all sorts of evidence of human evolution all over South Africa and elsewhere and a giant building full of facts about the same thing and we can't trace our ancestors back definitely to ascertain where exactly modern humans came from? 

That statement is correct. And it's because there just isn't that much evidence out there.

Mrs. Ples and Little Foot were found in the part of the Sterkfontein Caves that we visited in the morning. Know how many other specimens were found there? Zero. And people only realized Little Foot was a human ancestor about 15 years after the initial discovery. If someone hadn't taken a close look at the four human bones found in the mid-1980s and realized they were actually human and then sent a team back out to see if the rest of the skeleton was still there (it was) we'd have Mrs. Ples and that's it from that site. 

There have been other remains of humans found in other parts of the Sterkfontein Caves. There was an especially large find in the Dinaledi Chamber of those caves that produced the remains of at least 15 early hominids. 

There have also been other finds of ancient human remains all over Africa. This Cradle of Humankind in South Africa is not even the first Cradle of Humankind we have visited. We pulled into Tanzania's version of this same concept at Oldupai (or Olduvai) Gorge on the way from Ngorongoro Crater to Serengeti National Park in early 2018. At that site, there were discoveries of human bones dating back millions of year, including a skull, a partial thigh bone and some teeth of a fourth Australopithecus, along with more recent remains and tools from about 17,000 years ago.

Replicas of Little Foot's skeleton (top) and Mrs. Ples' skull (bottom).

So let's add all of that up on the Australopithecus side of things. Two skeletons from one part of Sterkfontein Caves and 15 (maybe) from another part and a few fragments of a skeleton from Oldupai Gorge. Yes, there were other skeletons and partial skeletons found elsewhere on the continent but come on...is that enough to establish a record of human evolution over millions of years? Probably not.

Part of the problem here (along with the millions of years) is the fact that mammal bones only get fossilized under extreme situations like sudden mudslides or things that like which capture solids and eliminate oxygen at the same time. Those kinds of conditions just doesn't happen that often as crazy as that sounds. Combine that with the fact that human ancestors millions of years ago were probably pretty for larger creatures and likely spent very little time preserving the remains of their dead and it's really not surprising there is very little out there in the way of traceable evolutionary history. 

So where does that leave South Africa's Cradle of Humankind as a tourist attraction? Oddly, it leaves it as both underwhelming and super-exclusive at the same time. 

On the underwhelming side, we spent a lot of time walking around some caves to see one spot where one of the two skeletons in that section of the cave were found and then visited another building that shed a lot of light on the path to discovery of our species' evolution. There's no conclusive answer on that subject because we just don't know. There's not enough to go on.

On the super-exclusive side, there are only so many spots on this planet of ours where real progress in finding evidence of our ancient ancestors as a species have been found. To say that we passed right by two spots where that record of our past existence was found in a single day is amazing. 

Sometimes on our trips around the world we get complete experiences that are incredibly fulfilling. This day wasn't one of those because it couldn't really be. But we've added another site that provided evidence of human evolution to our list. I am sure there are others out there where we will re-engage on this stuff in the future. No regrets on this one.

Cradle of Humankind No. 1 (Tanzania; 2018) for us. More of these to come?