field sites

I am pleased to announce a new open science initiative, focused on a discovery that is unique in paleoanthropology. Together we are going to find out if the Malapa site has preserved evidence of soft tissue from an ancient hominin species.

If you've arrived at this page from outside the site, here's a link to the main project headquarters.

In the August, 2011 issue, National Geographic reported on the Malapa fossils, including a teaser that the site may preserve skin from two hominin individuals. (I pointed to the article last month.)

The suggestion is obviously surprising. Many readers will remember how much controversy surrounded claims about soft tissue preservation from dinosaurs several years ago. Yet extraordinary preservation contexts do exist in the fossil record. Indeed, a few years ago Lee Berger's team, including several of the people now working on the Malapa hominins, identified hair preserved inside hyena coprolites from Gladysvale cave, more than 200,000 years old and only a short distance from Malapa [1].

Could Malapa present the first evidence of soft tissue from a fossil hominin? If so, what can it tell us about human evolution?

The day the National Geographic article was published online, I was standing with Lee in his lab looking at what might be australopithecine skin. I'm not talking about an imprint of skin, like a skin cast. These appear to be thinly layered, possibly mineralized tissue.

Suppose it's really skin, or some other soft tissue, I thought. How would you go about testing the hypothesis? Extraordinary claims require extraordinary evidence. Even if you could demonstrate it to your own satisfaction, what would it take to convince the doubters? How many distinct observations would be possible from these objects? What instruments would you use, and what comparative samples would you need?

Lee said this was his problem as well. He has access to some of the most sophisticated technology in the world. Some kinds of observations are obvious. He can micro-CT the apparent soft tissue evidence, look within the rock at its structure. He can sample the chemical content, and use scanning and confocal microscopes to examine it. He could sacrifice a small sample to be microscopically dissected. At the end, he would have an answer involving all these comparisons. But would it be convincing?

Lee then made an inspired proposal: What if the process itself were an experiment?

Much of the criticism of other surprising fossil discoveries has been fueled by their secrecy. Science done by a closed process means fewer eyes looking at data, and too many chances for errors to pass unnoticed. Unnoticed, that is, until publication. Then, a firestorm of controversy may erupt as the scientific community at last examines the methods and results closely. In anthropology, the most critical errors are often missed comparisons -- sometimes simple things that a research team could have looked at, if they had only thought of it.

An open process has the chance of improving research by broadening it. We want stronger, clearer results, and we want to anticipate every important criticism. If a significant comparison can be added by people who have the right tools, why not get those people involved? If we stand a chance of finding those people by making the process more open, why not do it?

Lee suggested that this soft tissue evidence could be the basis of a true experiment in whether paleoanthropology could be done as open science. I've been agitating about open science for years, and I volunteered right away to host the experiment and work to make it a success. We went immediately to Rachelle Keeling, the graduate student who will be coordinating the project, and described how we thought it could work. She was enthusiastic about the idea of a truly new kind of scientific project, one that had the potential to involve so many people in the process of discovery.

And so, after a month of putting things into order, here we are. How can you participate in the project, or at least follow its progress?

I have set up a home page for the project, here as a special category page on the blog. This page is the online headquarters of the work, and includes a feed that will have all project updates. As the project proceeds, it will generate suggestions, results, and press. I'll be tracking all of these and updating as we learn more.

The project has an official e-mail address hosted here: skin@johnhawks.net. We want to hear from anyone with the expertise or ideas to solve this problem. Rachelle and I will be reading through the e-mails, discussing them with other project members, and following up on them.

We don't know what to expect but I hope we get hundreds of responses. We can't promise replies to anyone, but everyone will receive an automatic acknowledgement that we've received their messages, and we will follow up personally with those that have suggestions or proposals we can take action on. We're going to ask people to participate in the project, perform research, and coauthor the scientific work: this is real open science.

Members of the Malapa team are biologists who know comparative skin and hair biology. I'll be posting quite a lot about these biological topics for people following the project.

We know that there are many researchers who have been working with methods that would be useful on these unique samples of possible soft tissue. People working with the trace chemistry of organic compounds in mineral samples, people working with the microscopic structure of other ancient soft tissue samples, people who study preservation of organic materials in forensic contexts. There are many others that I don't even know I should be listing.

If you know a person with the right expertise to help, please share this information and encourage her to write.

Most important to the success of the project is showing that we can produce top quality science by this open process. That means we need journals to acknowledge the value of open science instead of penalizing it for not being secret and embargoed. If you're a journal editor reading this, I'm calling you out. And if you're a reviewer or editorial board member, you can support this project and encourage more like it by encouraging the submission of open manuscripts.

And if you don't have a suggestion right now, keep watching. This project will develop and I expect it to become more interesting as it becomes broader. I can't predict how it will end, and that's pretty exciting!

References

I'm visiting at the Institute for Human Evolution at the University of Witwatersrand this week. Lee Berger has been a really wonderful host and among other things he very kindly took me out to the Malapa field site. As you can imagine, I'm pretty busy this week and haven't even had time to properly work up my thoughts on my Siberia trip. But I thought it would be fun to quickly share some impressions and photos of Malapa.

Malapa is a short drive from Johannesburg, but it takes only a short drive to really be in almost total wilderness. The site lies in what is now called the Malapa Nature Reserve (after the site) and adjoins the John Nash Nature Reserve. We arrived at the gate around 7:00 am, just after the orange full moon set in the west, and as the sun was rising in the northeast. It was a beautiful morning, no question.

We met Zach Cofran, a graduate student at Michigan, as well as a local painter that Lee has contracted to document the landscape before they construct a temporary shelter and begin systematic excavation at the site. This made for a pretty great opportunity to take in the surroundings, as we scoped out various overlooks on the area. Here's an overlook above the Malapa site itself:

Those rocks foreground are masking a steep pitch down, we were on a pretty tall hill.

The valley winding into the background is the Malapa drainage. Most of the dark green patches of trees are associated with some kind of karstic feature, either current caves or old ones that have largely eroded out. The landscape is really alive with cave formation processes -- the streambed itself drains into an extensive cave system and eventually emerges on the opposite side of the near hills.

We drove down from here along the track into the valley. Lee showed us the ranch house that will house a field school, and took us down the river track (sometimes actually in the streambed) to the site.

I would describe Malapa itself as a former cave. There is still a deep pit element, enhanced or largely created by blasting in the early twentieth century. Miners went prospecting for flowstones and other calcium carbonate features in caves, which they could reduce into lime by burning it in kilns. To get the stuff out, they had to blast through a lot of breccia -- essentially cemented sediments and debris that collect inside of caves. The breccia often contains bones of ancient animals, including in some cases hominins, sometimes very densely. At Malapa, the breccia is exposed at the surface, partly obscured by the miners' activity creating a road track along which the exploited other caves further up the hill.

Here's the existing pit:

That's Zach Cofran on the opposite side there.

The skeletons recovered thus far were found in surface blocks of breccia blasted out of this pit and in the edges of the pit itself. The breccia however extends over a much greater surface, making this an incredibly promising site for further excavation and discovery.

Well, it may not look like much in photos, but in terms of hominin fossils, it may end up being the most important fifty square meters in the world.

I'm almost ashamed to admit that after much turning over of blocks, I didn't find any hominins. At least not any that haven't already been found by somebody else first. But we had plenty left to see. A drive up a further track would take us to some other very interesting places. Lee drove us to the spot where the river comes welling back up out of its cave system -- as he described it, the water exits 75 years after it first enters. Here he is with his ridgeback companions:

After some geology I won't describe, along with an empty leopard den, we continued onward encountering many of the other species of large mammals on the nature reserve. Luckily, I use a Canon body so I could borrow the 400 mm telephoto lens to get some great shots. There were plenty of wildebeest:

And some giraffes (for Goodwin!):

And a kudu bull with a wonky horn:

Now, in my ordinary life I really have few occasions when a long lens would be very useful, but I could get used to having one for these situations.

Near the end of this little safari, we hit Gladysvale Cave, which has a very impressive large upper gallery and two lower ones we didn't enter. Lee worked Gladysvale for many years finding a handful of hominin remains but endless antelope bones.

It's a problem with field sites -- the hominins are only a part of an ancient landscape which was occupied by many species. Our relatives were patchily distributed, but they did end up in caves sometimes due to several different causes. The skeletons in Malapa are remarkably complete, suggesting a distinctive history of formation of the site. Large sites may be made up of many such episodes.

As for Gladysvale, it is still actively used by large herbivores, whose tracks go right into the cave. They may be seeking minerals, as there is no water pool inside.

This was near the end of our drive, and so I'll stop the story. Again, I've got lots to see ahead of me this week, but hopefully I'll have some Denisova news typed up soon.