Tag Archives: Ida

Palaeontologists go to bat for Ida

A new defence of the fossil Ida as a precursor to today’s primates, including humans, has emerged from the research team that last year bought and promoted the 47-million-year-old remains.

Ida, or Darwinius masillae, was described in 2009 by Jens Franzen at the Research Institute and Natural History Museum of Senckenberg in Frankfurt, Germany, and colleagues, who identified it as a haplorrhine, precursors to modern-day monkeys and apes. However, two studies by other groups since then citing evidence from a new fossil and an independent study of similar primate fossils concluded Ida was closer to the strepsirrhine branch, precursors to today’s lemurs, (see ‘Fossil primate challenges Ida’s place’).

“If you say ‘I have something in the line of hominids’, another palaeontologist will say you are wrong,” says palaeontologist John de Vos of the National Museum of Natural History in Leiden, the Netherlands, the author of a 2008 article in the Journal of the History of Biology on scientific disagreements about Neanderthals, Homo erectus and Homo floresiensis. But this particular disagreement is smaller than those, de Vos adds, because Ida is much further removed from modern primates and fewer palaeontologists study this area.

Creative scoring

Franzen and colleagues including Philip Gingerich, the lead author on the Ida team’s latest paper, wrote in a statement for the media that their new analysis “was made by excluding fossil taxa consisting only of small fragments like single teeth or jaws”.

They did not write that the new analysis excludes all fossils other than Ida, comparing her only to eight living primates. For comparison, similar studies of fossil primates by other researchers have examined up to 117 species. Franzen told Nature, “There are almost no skeletons comparable to Darwinius … our opponents are referring mostly to fragments of jaws and teeth.”

Other palaeontologists are not buying the argument. Palaeontologist John Fleagle of the State University of New York in Stony Brook says, “Why not include data from the many fossils from the past 54 million years?” Evolutionary anthropologist Blythe Williams at Duke University in Durham, North Carolina, lead author of one of the papers that placed Ida among the lemur ancestors, says, “I’d love to see an analysis like they’re doing with a much broader [range of] taxa”, including some “spectacularly preserved” fossil lemurs.

Building a family tree — or phylogeny — always includes some subjectivity: in addition to choosing which species to include, researchers must decide which characteristics of each species to include in the analysis, and then they must score each characteristic. For Ida, that might involve deciding which bones in the ear are relevant and comparing their shapes or relative sizes to those in other species.

Palaeoanthropologist Russell Ciochon of the University of Iowa in Iowa City wrote in an email: “the critical factor is always who did the scoring — don’t let Williams et al. off the hook here either — they are equally as guilty as Gingerich et al. when it comes to ‘creative’ character scoring.”

Yet many researchers agree that more data is better, even if not all the included fossils are as intact as Ida. “If you have a new fossil species … you have to compare it to other fossils,” says phylogenetic biologist John Wiens of the State University of New York at Stony Brook. “It’s not that controversial.”

Progress, funeral by funeral

The condition of the fossil is also a bone of contention. “If Darwinius were as beautiful and complete as we’re led to believe, there would be less controversy,” says palaeontologist Chris Beard of the Carnegie Museum of Natural History in Pittsburgh, Pennsylvania. “Its ear would be definitive.”

The ankle, which Williams and colleagues claim looks too crushed in photographs to be reliable, is also the kind of fragment on which other entire species classifications rely. Franzen says the team completed high-resolution computed tomography (CT) scans of Ida’s hands and feet (only the head was scanned in high resolution in time for the 2009 announcement) too late for the present paper, but that they are analysing the data now. Williams says that when one of her collaborators asked for access to Ida material before writing their paper, they were told it was not available.

“What we are seeing now with this current exchange of papers is nothing more than the normal back and forth of peer review that takes place every day in the pages of scientific journals far outside the public’s imaginations or interest,” writes Ciochon. “Science moves forward funeral by funeral … almost no one ever changes their mind.”

See this news story on Nature News [html] or here [pdf].

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When hasty headlines fail to shake a family tree

When a new species comes to light, its effect on the arrangement of its family tree might be better measured by statistics than by headlines. In a study of primates and flightless dinosaurs, researchers at Bristol University, UK, have found that the likelihood of any given find shaking up the family tree depends on how complete that tree was to begin with.

“What we’ve done is look at the two most intensively studied groups,” Tarver says, and highlighted differences between the relatively stable catarrhine family tree, and the less certain family history of the dinosaurs. He says that statistical analysis could help to indicate which areas in a given family tree are already well-sampled and which might yet reveal more influential finds.

See the rest of this news story on Nature News [html] [pdf]

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Nature Internship 7: Ida cont’d

nature_cover_090528Thanks to Ida the fossil primate I got out of the office last week, on Tuesday to see a screening of the documentary about Ida at the British Academy of Film and Television Arts and on Wednesday to interview Ida’s other half Jørn Hurum at the studio that produced the film. I blogged about the screening and Nature ran an online question-and-answer story culled from my interview.  Nature also ran a few choice quotes from the press juggernaut in the print magazine, along with an editorial, though I can’t take credit for the editorial. It’s trickier doing in-person reporting, but I really enjoy it and hope to include a little more of it in my work.

I also dashed off a quick blog on a US federal directive which halts road-building in about 50 million acres of US Forest Service land, a reversal of a Bush reversal of a Clinton rule. Not clear? Click here to read the whole thing.

Update: My interview with Jørn Hurum appeared on the Brazilian website terra.com.br on 2 June.

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Taking a fossil primate on the road

Jørn Hurum has accompanied the fossilized primate he nicknamed Ida on a world tour to fame and notoriety in the last week. The 47-million-year-old fossil is famous for its haunting completeness — the outlines of its fur and its last meal appear like a shadow around the intact skeleton. Yet Hurum has drawn fire for promoting the fossil and its potential links to human ancestors through a multi-platform media campaign alongside the release of a scientific paper that describes the fossil’s genealogy more modestly. Today, he and Ida paused in London to discuss the fallout of the publicity and the next scientific steps.

The book, the television programme and the press releases make claims that are not necessarily spelled out in the peer-reviewed journal article. What response do you have for critics who argue that your approach distorts the scientific process?

I don’t think a discussion of haplorrhines [tarsiers, apes, monkeys and humans] and strepsirrhines [the suborder of primates comprising lemurs and lorises] would be easy in popular science. You need to simplify it down to more understandable words. Of course in that you lose a little bit of the scientific terms, but really I think the message is very, very much the same in what we are doing popularly and scientifically.

There are many competing theories about how early primates fit together. What would it take to persuade other palaeontologists that Ida is closer to haplorrhine than strepsirrhine ancestors?

The three-dimensional reconstruction of the foot. That will be very, very obvious what it is when we do it. That will be solved this summer with new three-dimensional models of the whole structure. The CT [three-dimensional computed tomography scan] was only made from the skull.

The other thing we’re doing now as we speak is to scan plate B. We will make a three-dimensional model of the ear bones and they’re also very different in strepsirrhines and haplorrhines. These two things will happen hopefully within a year. I think we will settle a lot of the discussion with these two structures.

When will researchers outside of your group be able to examine the fossil themselves?

Already we’re discussing two different papers with different new researchers. The way to get access to good specimens in palaeontology is usually to get in contact with the researchers working on it and suggest cooperation.

At the same time what we have done already is of course to place casts in the American Museum of Natural History [in New York] and the Natural History Museum in London, and we’re going to place one in Senckenberg Research Institute and Nature Museum [in Frankfurt]… so it will be possible to study the outer morphology of the specimen from the casts within a few months.

Before we publish on it, we’re not going to release all the CT stuff, of course. That’s kind of the database for our research for a few years now.

Do you feel that there’s any kind of ethical responsibility to allow scientists to see new scientific results before publicizing them so they can prepare their responses to the media?

No. No. What we did is really to tell our story also in a popular format at the same time as we did a peer-reviewed paper, and that’s not illegal.

If there’s a phylogenetic claim and it’s corrected in future publications, does that not hand ammunition to creationists?

We cannot wait several years to tell the story just because it might be corrected. This is science. Higher-rank phylogeny is something that is extremely volatile. It changes with different authors. This will jump around cladograms for the next ten, fifteen years, I’m sure. But it will never be difficult to say that this is an important specimen.

Did you offer it to any other journals before it was accepted by PLoS ONE?

No. Phil Gingerich had a very good experience with PLoS for his Maiacetus paper in February so he was the one suggesting PLoS.

How important was it to put all the media elements together in one piece?

Of course it works better if you do that. History Channel wanted to run on Memorial Day.

We didn’t know if we were going to make the paper happen at the same time until the week before it happened. I believed we were going to have to cite the paper as ‘in press’. PLoS said they could really put the work into making it happen — the technical part. It’s cited somewhere that it was pushed through review. That’s not true. But [laying out the paper] was a little bit pushed through to make it happen on the same day.

In the end the timing came out perfectly but that was just luck, really.