Africa has long been known as the site of from which modern man first radiated out to populate the world. Much attention has been directed to the eastern African Great Rift Valley as the origin of humans, great apes, and chimps (hominids) but several candidates as the actual ancestor of humans (hominins) are likely evolutionary dead ends. The attention has shifted within the last decade to new important fossil discoveries in South Africa that may fill in some of the gaps in the family tree…..which looks more and more like a bush.
I was the recent guest of Dr. Lee Berger, National Geographic Explorer-In-Residence and professor at University of Witwatersrand, who has made TWO exciting discoveries in recent years. The first, in 2008, was discovered by his 9 year old son Matthew who was in the field with his dad. The remains of 6 partial skeletons dated to 1.9 million years ago belong to the Australopithecus species, the same apparent lineage as the famous 3.2 million year old early human Lucy, Australopithecus afarensis. This new species, Australopithecus sediba, is noted for its features of both primitive and modern humans, suggesting it may be a transitional species.
If this discovery wasn’t enough for a lifetime of study, Dr. Berger and his team led by Dr. Marina Elliott recently discovered an entirely different early human species though of the same approximate age and in the same general location. This species has more traits of modern humans but retains some primitive features, again suggesting that human evolution was in transition. Amazingly, Dr. Berger has begun recovery of at least 15 skeletons, several nearly complete, making the discovery of Homo naledi one of the most intriguing paleoanthropological discoveries of all time. This was just announced in September with much more information to be announced in the future. For the interested reader, check out the Rising Star Cave program at National Geographic.
Both discoveries occurred in cave areas created when limestone-like deposits eroded leaving holes in the surrounding more condensed rock. It is into these caves that I was able to go with Dr. Berger and his team to view the discovery sites of both species. The actual site for H. naledi is in a location of very difficult access and many fossils remain so we did not go directly deep into the cave. The area is teeming with fossils, and along the route were several Bronze Age fossils that have not even been evaluated yet. One has to be careful in these caves because of steep, narrow gaps. Masks must be worn because of the ever-present bat guano which contains spores that if inhaled can cause histoplasmosis, a very serious lung infection. Believe me, the magnitude of these discoveries already took your breath away.
The dig sites are about 40 km outside of Johannesburg, located in a game reserve. So, when we were not looking at amazing fossils, we were on the lookout for game. The drives through the reserve got us up close to giraffe, elephant, zebra, rhino, kudu, and many other antelope species. We did find a leopard den on foot, which had me nervously looking over my shoulder. Once back in Johannesburg, we spent time in the lab with world class scientists from various countries, evaluating the fossils and learning about the unique characteristics of the specimens. This gives an interested amateur like me a whole new perspective when looking at a tooth, for example. I now understand why one might make many claims regarding age, diet, probable climate, species of origin and other traits from observation of a single fossil.
Talk about a great adventure, spectacular early human fossils and African game. This one is very hard to beat. Stay tuned for more!
Michael J. Manyak, MD
VP National Eagle Scout Association
Author, Lizard Bites and Street Riots, Travel Emergencies and Your Health, Safety, and Security
November 6, 2015