We want to thank everyone who has assisted with the project. If you're just arriving here, welcome!
Rachelle Keeling has completed the first round of analysis, including several parts based on suggestions of the open project. She is moving forward to publish the results and when they are through review we will be able to share more.
Kate Wong: "Is Australopithecus sediba the Most Important Human Ancestor Discovery Ever?"
Second—and this may sound a little insidery, but it’s critical–the way Berger and his collaborators are studying the finds and disseminating what they learn represents a real departure from the cloak-and-dagger manner in which paleoanthropological investigations often proceed. Berger has assembled a huge team of specialists to work on the remains and has made the project open access, with a policy of granting permission to any paleoanthropologist who asks to see the original fossils. He has also sent out scores of replicas to institutions around the world, and routinely brings casts of the bones—even ones that his team has yet to formally describe–to professional meetings to share with other researchers. This can only improve the quality of the science that comes out of the project and may well inspire other teams to be more forthcoming with their own data.
Malapa is the perfect site at the perfect time. Many people have scoured that area looking for something like Malapa. If they had found it in 1950 we would have the skeletons, but would have lost much of the context. The open approach is fundamental to the science because it enables the best people to do their best work.
Is Au. sediba the most important ever? As Wong writes, we must match the find with the moment. Clearly right now, Malapa poses fundamentally new questions and provides evidence to address them. It is not alone: Denisova likewise has produced (and is still producing) vast reams of new data and raising new, unforeseen questions. Other key sites belong in this league: Sima de los Huesos, Dmanisi.
We have yet to see the full importance of these sites, as they are still unfolding. It is our job to find the contradictions between these new finds and our earlier hypotheses, and use them to discover the real story.
An article by Veronique Greenwood covers the discovery of feathers on a North American dinosaur: "Paleontologists Uncover the First Feathered Dinosaur Fossils in the Americas". Dinosaurs are remote from hominins, but there is one aspect of the story to which I wanted to draw attention:
The finds had implications beyond the obvious. Ornithomimids were first unearthed more than 100 years ago, but paleontologists only learned about the existence of dino feathers 15 or so years ago. And the fact that no one had ever looked for feathered dinosaurs in river sandstone before got the researchers thinking: "What about fossils that were collected 10, 20, 30, 50, 100 years ago?" Therrien says. "If paleontologists had known it was possible to preserve impressions of soft tissue in sandstone, well, maybe these other specimens were covered with feathers, and they were just destroyed during preparation."
Our methods of recovery and preparation of fossils may, in some cases, be destroying evidence of soft tissue or non-bony structures. The preservation of such structures is idiosyncratic and rare, and so not readily predicted in any particular fossil context.
Archaeology has gone through similar revolutions in the past. Archaeologists used to discard sediment after it was sifted; later they began to employ flotation of the material in water, which in some cases allowed organic remains to be separated and identified. Calculus was once scraped off teeth to make them easier to study; now we know that the calculus can preserve phytoliths and starch grains that provide strong evidence of diet.
It's not obvious how fossil preparation and recovery might be altered, but clearly with the Malapa site, excavation and preparation team is planning with extreme care for exactly this kind of reason. If paleontologists are finding dinosaur feathers in sandstone, any context with articulated hominin bones needs to be considered with extreme care.
The "Science Friday" NPR show with Ira Flatow did an interview with Lee Berger and Bernard Wood yesterday about Australopithecus sediba. The transcript is now online: "Examining Ancient Fossils for Clues to Human Origins", or you can also get the audio.
This is a nice interview with a lot of detail. I especially like the later part where Berger promotes the importance of getting more researchers into field discoveries.
Remember, that this was recovered right in the middle of the most explored area, probably, in the continent of Africa - for these very fossils, lying on the surface so easy a nine-year-old could find it. And there - Africa is a big continent. It is unexplored. The rest of the world's a big place, and we need to get more exploration and find more fossils. And I think that that is a clarion call at sediba rings out, that I think Bernard was alluding to as well.
Oh, and there's this:
We are allowing scientists to examine this material, published and unpublished, anything we find. Any bona fide scientist can come to our labs and examine, whether we published it or not. So we're attempting an open access experiment. We've casts available. You, today, could go to the Smithsonian Museum or the American Museum of Natural History and see casts of the material that we published in Science today. They've been in those institutions for months and months and months, available to any scientists who wanted to look at them.
My photo of the hand (cast) of MH2:
My commentary on the new papers will be coming. I've been very busy today filming, but I'll catch up after our bullriding adventure tomorrow.
This is the kind of thing I never get tired of: Figure S7 from the supplement of the Malapa foot paper by Bernhard Zipfel and colleagues [1].
Figure S7 from Zipfel et al. 2011. Original caption: "Fossil hominin tali in distal view. Left tali have been reversed so that they all appear from the right side. All tali have been scaled so that the trochlear body is the same mediolateral width. There is tremendous variation in the torsion angle of the head, and in the grooving of the trochlea in fossil hominins. Notable in this orientation is the remarkably large talar head of U.W. 88-98."
We see too many papers where a fossil is displayed next to a chimpanzee and a human, maybe another hominin, as if they were Platonic types. Here we see immediately the variation among a good sample of hominin tali from East and South Africa. Four from Sterkfontein and four from Turkana, so you can see variation within those samples arrayed right across the figure. A figure like this takes more interpretation than a graph showing measurements or principal components, but it has a visual impact that a Cartesian plot can't match.
In the supplement of Kristian Carlson and colleagues' paper on the MH1 endocast [1], there's a nice comparison of the medical CT versus synchotron images. My blog sizing can't do it justice, and to be honest, the online PDF in Science doesn't either, but you get the idea:
Figure S10 from Carlson et al. 2011, detail. Original caption: Comparison of the same slice of the MH 1 cranium obtained with medical CT (left) and synchrotron scanning at the ESRF (right). Voxel sizes are approximately 450 μm and 45.71 μm, respectively.
You know, someday we'll all have these data for the entire fossil record, and students won't think a thing of it.
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!
These are a few of the questions that I think are essential to understand our aims with the project and how we expect it will unfold. The future depends on what we hear from people with their ideas about how to analyze this unique evidence. I'll be updating this FAQ as we learn more about the samples. This is an open science project, and we'll be reporting on some results as they occur. But it all depends on people's participation.
If you've arrived at this page from outside the site, here's a link to the main project headquarters.
When I was in South Africa in July, Lee Berger gave me an extraordinary overview of the discoveries from the new Malapa site. Embedded in the breccia that surrounded the cranial remains of MH1 and MH 2 are some relatively small, thin layers that visually appear to be organic (relative to the surrounding matrix). Under a light microscope look like they could be mineralized or preserved soft tissue. They do not appear to be skin impressions within the matrix, they appear to be thin layers that are a different substance from the surrounding matrix.
Naturally these are incredibly interesting. But it is not obvious what will be the best way to establish what they are, and what we can learn from them.
Lee suggested that this would be an ideal test case to see if open science can help solve a problem in paleoanthropology. We want to reach the people with the best ideas and ability to test hypotheses about these objects, and we don't know in advance where the answers will come from. That's the nature of the project: finding the right people and making the science happen.
We want the best suggestions about how to evaluate this unique evidence and how it can test hypotheses about human evolution. We're reading all the suggestions sent to skin@johnhawks.net.
We're especially keen to make contact with people who have the ability to make their suggestions happen. Some people out there have the knowledge to apply highly specialized analytical methods to samples like this. We want people like that to get involved with this project.
Some people out there may have comparative samples that will be key to interpreting this evidence. How can tissue be preserved in a context where breccia is forming? Was there natural mummification or some kind of anoxic environment? To answer those questions, we need people who study the response of tissue to those contexts and who know the right samples to examine.
Berger's team working on the Malapa hominins have access to much of the best technology. Micro-CT, microscopy, virtual dissection, chemical analysis, any of these things and more can be brought to bear.
There's a lot more to this project than simply verifying (or refuting) that this stuff is soft tissue evidence. We need to know how it formed. If it's not soft tissue, we want to identify what it is, because there will almost certainly be more of it as the site is excavated and more specimens are prepared. If it is soft tissue, we need to know how it may have been changed as it was preserved, whether through drying, soaking in anoxic conditions, mineralization, or some combination of processes.
We think the process of finding this out is even more exciting than knowing the result. We hope many of you see it the same way.
If you write to us, you can expect that we may make your suggestion part of the website. This is an open project, and while we will be posting selectively, we will be sharing information as it progresses.
We want to do the science right. We hope many people out there share this goal. It's a tremendous chance for people who don't normally operate within paleoanthropology to help us discover something fundamentally new about our evolution.
People who perform analyses or contribute samples as part of this project happen will be full participants in the science and coauthors of any resulting publications. We want people to work together on this, and we think the best science will result from bringing together the best ideas and comparisons.
That depends on what great ideas we hear from people. Lee's team will be carrying out analyses on these samples.
Rachelle Keeling is coordinating the study, doing the research on what should be done, and what it will tell us about the samples. She and I will be reviewing the e-mails that the project receives, and will try to determine which approaches are feasible, and which order they should be carried out.
As you send in ideas about what should be done, the more detail you can include about the analytical methods you can provide, the better. How much material (if any) does the method require? What hypotheses can the method test, or what information can it provide about the samples? How much time and preparation is required?
If you have comparative samples that may be useful, what kinds of observations can you make on them? Can you point to references that have also used these samples?
In other words, we want a bit of a plan if you can provide it. If you need more information from us to see if it's feasible, let us know -- we may be able to answer it, or have some team members carry out steps in advance.
The project will be carried out over the next year, so the sooner we hear from you, the better!
Malapa is a cave site outside Johannesburg, South Africa, in the area where many other sites preserving remains of early hominins have been found. I have a Malapa page that gives a short introduction and links to many stories here about the fossils found at the site. I visited the site in July, 2011, and posted a narrative of the visit ("A visit to Malapa") that gives a good overview and several photos of the general area.
Two of the most complete hominin skeletons ever described, both dating to 2 million years ago, have been discovered and described at the site. The site additionally includes further fossil materials that are still undergoing preparation and study. It is one of the most important fossil discoveries ever made in paleoanthropology, and will continue to produce new evidence about our origins for many years to come.
So far, the team at Wits has been working on breccia blocks recovered from the surface at Malapa. There has been no excavation yet at the site. The possible soft tissue evidence was discovered during the course of scanning and preparing these breccia blocks.
The blocks are packed with bones. Many recognizable bones jut from the surfaces of the breccia, from antelopes, carnivores, small baboons and hominins. In several cases, hominin bones were recognizable at the surface, and these blocks were CT-scanned very early in the process of study and preparation. Scanning gives the preparators knowledge of what lies beneath their drill bits. In some cases, the best course of action is to leave the bones embedded within the breccia matrix, for further study by micro-CT.
Initial CT scan of the MH1 cranium embedded in matrix block.
In the initial CT-scanning of the MH1 cranium, team members noticed an area where the matrix surrounding the skull appeared irregular. As they prepared this out, it became clear that the breccia itself had pulled away from the cranium across a small region, and the breccia had a thin layer of material at its surface there. This is not the outer table of the bone (which is intact in the corresponding area), nor is it apparently an impression of the bone.
Photo of breccia block including MH1 cervical vertebra (top). The smooth area, center, is a thin layer of candidate soft tissue on the surface the breccia.
An additional section of possible soft tissue emerged as the female MH 2 mandible was prepared.
Upon magnification, these pieces do appear to have a structure. As yet, no dissection or further sampling has been attempted. The team has no committed opinion about what these represent or how they were formed, other than that they do not appear to be simple impressions in the surface of the breccia. Disproving that they represent soft tissue may be just as interesting as demonstrating it, because either way we will discover important facts about the preservation and formation processes of this unique site.
Like other South African cave sites, the Malapa fossil hominins were preserved within a breccia, a cemented stone material packed with fossils, rock fragments, and other material. The Malapa breccia represents a remarkable snapshot of time, when hominins and other animals fell into a "death trap" and their complete skeletons were preserved.
It is clear that Malapa preserves an extraordinary density of hominin remains, with nearly complete skeletons and articulated parts. These skeletons do not appear to have been disturbed after the bodies entered the site. Some plant and insect remains are preserved in the breccia as well.
Beyond this, any explanation so far is speculative. If there was water in the site, which seems likely, it may have included an anoxic layer that preserved some of this material. A major goal of the project will be testing different hypotheses about the preservation environment of these fossils, to try to explain what these substances may be.
:)
National Geographic has posted text from Josh Fischman's August article about Australopithecus sediba: "Malapa fossils".
This raises the possibility, says Berger, that all the hominins—at least four are now known from the site—died weeks or even days apart, and therefore may have known each other in life. The rapid burial also caused their flesh to take longer to decompose, packaging the skeletons in death as they were arranged in life, right down to tiny bones of the hands and feet. Indeed, the rapid entombment may have preserved some of the skin itself, on top of the boy's skull and on the woman's jaw near the chin—something never before seen in a hominin fossil.
It's pretty cool to be here with the fossils and the people involved in the story right now. The story nicely features many members of the extensive team involved in the preparation and analysis -- a process that has unfolded so far in less than three years from the discovery of the site.
The article emphasizes what may be the central scientific problem posed by A. sediba: what it means for early Homo. As I wrote last month, the origin of Homo is by far the most interesting problem in human evolution right now.
