Unlikely that Homo naledi lived alongside Homo sapiens

Prof Lee Berger’s announcement on Tuesday (9 May 2017) that the bones of Homo naledi have been reliably dated to between 236,000 and 335,000 years old is big news. It is also big news that his collaborators have found another chamber within the Rising Star cave system near Johannesburg containing yet more H. naledi  bones, including the almost complete skeleton of an adult male.

Narrowing down dates for the hominin fossils is remarkable because many palaeontologists, including Berger, had believed that based on their appearance, the bones were at least two million years old. If these estimates had proven to be accurate, it would have placed H. naledi  at the base of the Homo genus as one of the oldest species in our family tree.

The dating issue became controversial because the first bones were found in 2013 and presented to the public in 2015 without any evidence for their age. Some professionals insinuated that the absence of a reliable age for the bones showed that Berger and his team had rushed their investigations.

After a long wait, Prof Paul Dirks and his team published a paper this month in the online journal eLife showing that the concentration of radioactive elements and the damage they caused in three fossilized teeth mean that the fossils are most likely between 236,000 and 335,000 years old.

To ensure that the results were accurate, the paper confirms that “the most crucial tests were carried out at independent laboratories around the world, and the scientists conducted the tests without knowing the results of the other laboratories”.

The fact that the Rising Star fossils are much younger than had been expected does not necessarily mean that H. naledi  should be removed from the base of our family tree. It is possible that about 2.5 million years ago, there was a fork in the original family of H. naledi  where one part evolved into H. erectus and eventually H. sapiens, while the other side lingered on unchanged as H. naledi  for another two million years or so. 

While there is no evidence to support this possibility, it cannot be ruled out. It is quite probable that H. naledi  will turn out to be an evolutionary dead-end – an interesting one – but nevertheless quite dead.

However, what is likely to be the most controversial aspect of Berger’s announcement is his claim that “H. naledi  possibly lived at the same time, and in the same place, as modern humans”. This is the angle that led in most mainstream publications in South Africa.

The Port Elizabeth Herald declared unequivocally that “Homo Naledi lived with man” even though not a shred of evidence was presented to support this dramatic claim. The newspaper said, “About 300 000 years ago‚ South Africans shared their land with another human-like species: Homo Naledi”.

This statement created erroneous impressions that first of all, there were South Africans; and secondly that these South Africans lived in harmony with relatives of another species. We can almost imagine them breaking bread together and perhaps sharing a fraternal beer in the spirit of ubuntu.

News 24 online news site said, “scientists and researchers can now reveal that it is highly likely that the species lived alongside Homo sapiens” suggesting that they hung out together.

Even Wits Vice Chancellor Adam Habib got caught up in the political feel-good spin conjured up by Berger and according to the Herald said “The true significance of this research shows we belong to a common humanity. That is a fundamental thing.

“In a world of division … when people are looking at their ethnicity to define who gets what and in a world where we are becoming so intolerant of each other‚ this research shows we have very common roots. We represent a common humanity.”

Actually it doesn’t.

The real problem with portraying humans and H. naledi  as best buds is that there is no evidence to show that they were alive at the same time. If we take the youngest date for the existence of H. naledi  as being 236,000 years ago and the oldest date for anatomically modern humans as being 200,000 years ago – there is quite a large gap of around 36,000 years.

It is true that someone might find evidence to support the notion that H. naledi  is  younger or H. sapiens is older, but currently this possibility is not sustained. Things might change, but in terms of current research, Berger is stretching the boundaries of what might, conceivably be possible into the realm of what could be good publicity for his book - which coincidentally was published on the same day as his dramatic announcements.

Our house according to Google Street View

This is what our house looked like from Market Street before we got the new garage doors

The Origin of Humans Is Surprisingly Complicated - Scientific American

The Origin of Humans Is Surprisingly Complicated - Scientific American

Springvale Olive Farm - a great outing

Craig Rippon loves olives. He speaks about them with a passion that lights up his face and inspires visitors to buy armfuls of olive products before they leave his estate near Alicedale. Close to forty people joined the tour of Springvale Olive Estates at precisely 10.30 on Saturday morning at the start of a most enjoyable outing.

Rippon led the walking tour of the estate and did not stop talking about the different types of olives and their relative strengths and weaknesses for two hours.

First we walked across the main road linking the N2 to Alicedale and then huffed and puffed up the hill to see rows and rows of neatly aligned olive trees. Rippon has planted just over 7 000 trees of 12 varieties since he started the project in 2000.

Most of the time he talked about the Mission olives and the Manzanillas that the crafty Western Cape farmer surreptitiously slipped in among the Mission seedlings, but there were also the Kalamatas, the Frantoios and others with exotic sounding names.

One of the visitors asked Rippon what was his favourite type of olive – a question he was not able to answer because he says he loves whatever is being harvested at the moment. Why olives? After all the Eastern Cape is not known as an olive producing region. He explained that his family had bought the farm from the Wilmots in 1915 and ever since then his family raised sheep, cattle and sometimes even Angora goats. He realised however that stock farming was becoming ever more difficult in the area as game farming gained momentum.

The game farms allowed for the proliferation of small predators such as jackals that frequently took his lambs. As the predators lived in a conservation area it became increasingly difficult for him to protect his flocks. He said that his grandfather had at one time planted mielies on the farm but baboons helped themselves to his crops too often. On the other hand, olives that come straight off the trees have an unpalatable bitter taste so they are almost never stolen by people or animals.

Rippon has six permanent staff members and up to 40 seasonal workers who help him manage and harvest the olives. The groves cover roughly 34 hectares and can produce more than 100 tons of olives in a season. His best year was 2007 when he harvested just on 115 tons but the long drought that followed slashed production drastically and he was forced to pump his dams dry just to keep the trees alive. At the end of the tour, visitors were invited to taste the various types of olives produced at the estate, and of course everyone was trying to decide which type to buy and take home. Guests could then have lunch on the patio or a beautiful lawn outside the farmhouse.

Lea Davies from a farm in the Adelaide area and Lisa Mickelwright, a teacher at DSG, prepared the platters artistically made up of various types of olives, smoked ham and salami kebabs, cumin seed cheese, olive tapenade and grapes.

Clean air, a selection of Mediterranean style treats, a glass of wine and good weather made the outing a massive success for all concerned.