Tuesday, April 25, 2017

Will the real date of Homo naledi please stand up?

The hand of Homo naledi
Most of my readers know that I'm kind of excited by Homo naledi (or is it dangerously obsessed?  It's hard to tell sometimes.)  I've been eagerly awaiting news of the date and lead researcher Lee Berger's next discovery since news of H. naledi broke nearly twenty months ago.  To review, H. naledi was discovered in a nearly inaccessible cave chamber in the Rising Star cave system north of Johannesburg, South Africa.  The site is literally around the corner from two other important fossil hominin locations, Swartkrans and Sterkfontein, so the fact that something this amazing had been sitting under our noses all this time is kind of delightful.  What else might be lurking right around the corner?

H. naledi is a weird mix of traits.  The skull is small, and the arms are fit for climbing.  But the feet and legs are clearly made for walking, much like ours.  Reports from the latest meeting of the American Association of Physical Anthropologists, held last week in New Orleans, indicate that H. naledi had a brain anatomy similar to modern Homo sapiens and might have been able to talk. With this mix of traits, H. naledi looks like a category called "early Homo," which includes taxa like Homo habilis and Homo rudolfensis.  These guys don't look a whole lot like modern people, which raises very interesting questions about what exactly they are.  With H. naledi, its identity is even more interesting, since the evidence indicates that they buried their dead, which is a decidedly modern behavior.

If you've read my blog at all, you probably know that Berger's been sort of teasing his next big discovery for at least a year now.  When I heard him speak at AAPA last year in Atlanta, he indicated that the next big discovery would be out at the end of 2016 or maybe the beginning of 2017.  On Twitter, he's been quoted as indicating a date coming at the end of February, then March 18, and then sometime in April.  Berger's book Almost Human describing the H. naledi discovery was originally slated for publication in March, then pushed back a month to April, and is now set for May 9.  Clearly something is delaying the technical publications that describe the date and the new H. naledi discoveries, and now the leaks have started becoming a bit of a flood.

A new article in New Scientist today describes a date for the fossils from a published interview with Berger.  The date is 200,000 to 300,000 years ago, but Berger doesn't specify how they got that date.  The frustrating part of this date is that it's not exactly what's published in the book.  As I reported on March 2, you can check out some details about the date using Amazon.com's "Read Inside" function for Berger's Almost Human book.  On p. 217, we read that the date is between 250,000 and 450,000 years ago.  Which date is correct?  Who knows?  As I write this, the technical papers haven't been published yet.

The weird thing about all this is that Berger championed open science during the H. naledi excavation and during interviews after it was published.  He put the papers in an open access journal and emphasized how important it was to keep the public aware of how science works.  That's great, but there's a bit more to the story.  The first thing I noticed was that the open access journal eLife wasn't his first choice for publishing.  Nature rejected the H. naledi articles, presumably because the fossils were not dated.  Nature is not an open access journal, and neither is Science, which published Berger's articles on A. sediba.  The H. naledi articles that describe the details of its anatomy were published earlier this year in the Journal of Human Evolution, which is not only not open access but is published by Elsevier, one of the chief "villains" in the open access movement for its record-setting revenue generated by charging exorbitant publication and subscription fees.  Would you like a personal subscription to Journal of Human Evolution?  That'll be $572, please ($48 per issue).  On second thought...

Read through the rest of chapter 30 in Berger's Almost Human, and you'll find out about Chamber 102, which is also part of the Rising Star cave system and also contains Homo naledi remains.  Yes, Virginia, there really is a second burial site.  Wow!  When did this happen?  According to the book, they were excavating the second burial site at least since February of 2014.  That's more than a year before the first H. naledi publications appeared in September of 2015.  So the whole time they were excitedly talking about the Homo naledi discoveries at site 101 (the Dinaledi chamber), they had an ace up their sleeve in the form of site 102.  While they were passing out replicas of their composite Homo naledi skull from site 101, they knew they had an even better skull from site 102.  That's not exactly open science.

On the other hand, Berger does have one genuine, deep, and unmistakable commitment to openness in paleoanthropology.  He has led the way in breaking the old system of holding onto fossils for years while they're privately studied by a select few.  For example, Berkeley paleoanthropolgoist Tim White reported the discovery of Ardipithecus ramidus in 1994, but it took fifteen years before details of the fossils were finally published (and White seems to think that limited access and years of tedious private study is the correct way to do science).  Berger's team found H. naledi in 2013, and published the first papers in September of 2015.  Today, there are at least ten technical papers on H. naledi covering details of anatomy, phylogeny, and taphonomy.  The number of work hours spent on Ardipithecus and Homo naledi are probably similar, but Berger employed a much larger research group to speed up the process.  Berger's preference for rapid publication is far more open than things have been in the past, and frankly, I like it much better.

What will the date mean for the study of Homo naledi and other fossil hominins?  It's hard to say without the technical details.  In the meantime, I guess you can read the commentary at New Scientist.

Feedback? Email me at toddcharleswood [at] gmail [dot] com. If you enjoyed this article, please consider a contribution to Core Academy of Science. Thank you.