john hawks weblog

paleoanthropology, genetics and evolution

astronomy

  • Star search

    Tue, 2010-09-14 12:56 -- John Hawks

    Should we begrudge the astronomers their "Lucy"?

    The cosmic diamond is a chunk of crystallised carbon, 4,000 km across, some 50 light-years from the Earth in the constellation Centaurus.

    It's the compressed heart of an old star that was once bright like our Sun but has since faded and shrunk.

    Astronomers have decided to call the star "Lucy" after the Beatles song, Lucy in the Sky with Diamonds.

    It is, after all, actually in the sky and does have actual diamond in it.

    Still...couldn't they have been more original?

  • Sneaking infrared peeks

    Mon, 2010-07-05 12:24 -- John Hawks

    The BBC reports on the initial public release of imagery from the Planck telescope, a space-based observatory of the far infrared to microwave spectrum. The pictures are pretty, and all, but what surprised me a bit is the part I bold-faced here:

    The project team will need a while to analyse all the data and assess its significance. A formal release of fully prepared CMB images and scientific papers is not expected before the end of 2012.

    However, such has been the anticipation for Planck data that one or two groups have already tried to make unauthorised interpretations simply from the images released to the media like the one on this page.

    But Dr [Jan] Tauber says this activity is pointless.

    "The CMB is certainly visible but the image itself is colour-enhanced so you couldn't do any science with that," he explained.

    "We have also reduced the resolution of the image to something which is more manageable for people to look at. Otherwise it would just be too big."

    It's interesting to me that paleoanthropology is not alone in people trying to jump the gun on the release of information. Genomics seems to have this problem mostly under control, despite the rapid open release of big datasets, but that may be because of the relative lack of widespread preprint availability by ArXiv.

    It's not necessarily pointless in this case -- although the data may not be good enough for the purpose of accuracy, some non-obvious interpretations of major features may be easy for a specialist to make based on low-resolution pictures. Not up to publication standards, but as for disseminating your interpretation on a preprint server they may be enough.

    That's certainly the case in paleoanthropology, where a glimpse of a new fossil makes some things very obvious. You can see why the "ownership" of data is a big issue, particularly as data more and more are the product of large international groups of scientists.

  • Moon units

    Wed, 2010-05-26 08:30 -- John Hawks

    NPR has a story about public analysis of data from NASA's Lunar Reconnaissance Orbiter:

    Only one problem: The LRO is doing such a good job that the scientists can't keep up.

    Enter Oxford astrophysicist Chris Lintott. He's asking amateur astronomers to help review, measure and classify tens of thousands of moon photos streaming to Earth. He has set up the website MoonZoo.org, where anyone can log on, get trained and become a space explorer....For example, "we ask people to count the craters that they can see ... and that tells us all sorts of things about the history and the age of that bit of surface," Lintott explains.

    I wonder if we could crowd-source morphology? I'd prefer a majority-rules approach to some of the bickering about which features are present or absent. The article mentions how they deal statistically with mistakes in classification.

  • Museums decentering the human

    Fri, 2010-03-19 08:30 -- John Hawks

    A very interesting essay by Edward Rothstein in the NY Times special museum section: "The thrill of science, tamed by agendas".

    Rothstein features a comparison of the human-centered renovation of the Griffith Observatory, and the new Rose Center for Earth and Space in New York, which goes with more of a pale blue dot theme.

    Of course, the insignificance of human existence is one of the fearsome lessons of modern science. But when we are young, we learn differently. We begin by learning to value our own understanding and only gradually come to recognize its limits. We begin by making sense of the world before we see how much lies beyond sense. The process doesn’t work well in the other direction: we can be left mystified by the world and lose respect for the human.

    Something like this has started to happen in some museums. This decentering of the human can become a devaluing of the human; the museum may even begin to see human frailties as a great flaw in the cosmic order that must be repaired. So this new variety of science museum must not just display or explain. It must be relevant, useful, practical, critical — something that helps with fund-raising as well.

    From there, he covers the "self-loathing" that seems to have crept into natural history museums concerning humans and nature. Some of his comments are reasonable, some hyperbolic, but all thought-provoking.

  • To the stars!

    Wed, 2009-05-20 18:03 -- John Hawks

    Razib pointed me to this really interesting article (by Lee Billings) about the search for planets around Alpha Centauri.

    I find this kind of science interesting because the detection of these really subtle signals in a big pool of data is a lot like what we do in genetics.

    For each one of the hundreds of thousands of observations, Fischer’s custom-coded software must model and counteract the various transient distortions caused by the instruments, fluctuating weather and temperature, cosmic rays striking the detector, even the Earth’s motion through space. The software compares the observed spectra of Alpha Centauri A and B to a spectrum from the calibrating iodine cell, then to a high-resolution spectrum of both stars taken through a larger telescope with a newer spectrometer. This comparison provides the wavelength shift, which is calculated and plotted for each observation. With enough time and sufficient numbers of observations, any planets around either star should manifest as tiny periodic shifts in the light’s wavelength.

    It's complete with a theoretician, who proves that the signature should never be there for an Alpha Centauri-like system. More and more like bottlenecks...

    Then there is this anthropic aspect -- the Copernican principle is that our current place and time is in no way special; it's just another place. But in some respects our current place and time strike some of us as unusual.

    “If we were plopped down at some random point in the galaxy, there’s only a 1 percent chance we’d find ourselves near stars so optimal for detecting small rocky planets like our own,” Laughlin said. “The hand of fate has dealt us a very interesting situation that has not existed for at least 99.9 percent of Earth’s history. It’s remarkable that Alpha Centauri is right next door just as humans emerge and develop the ability to make these measurements. I’m enamored with that coincidence.”

    Likewise, humans are at a very unusual point compared to our evolutionary history, with rapid environmental and demographic changes making some genetic signatures vastly more likely than ever before. And besides all that, these guys also have a blog.

    Now, if only I could develop a skill for tilt-shift photography, the parallels would be complete....

  • Archiving old data: The case from astronomy

    Sat, 2009-05-02 10:16 -- John Hawks

    I'm catching up to the news. Last week, Science carried a report by Yudhijit Battacharjee, about some astronomers' efforts to build digital archives of old photographic plates. There are collections of tens of thousands of these plates, each of them a small snapshot of the sky at a moment up to 150 years ago. The point of an archive is so that researchers looking for long-period phenomena can look at direct historical reference points.

    Proponents argue that old plates provide the only way modern astronomers can study astrophysical phenomena on time scales longer than a few decades. "Why would you want to wait another 100 years to learn how certain stars might be varying in brightness and position over long time periods when we have this resource right here in front of us?" asks Grindlay, referring to the Harvard collection.

    Preserving and scanning old plates, however, has been slow to win support from the broader astronomy community and funding agencies. Universities and observatories often discard plate collections when astronomers retire. Digitization projects in the United States and Europe—including DASCH [Digital Access to a Sky Century at Harvard, the project described in the article]—have proceeded in fits and starts on shoestring budgets.

    "We live in a world where money is fixed—so the question is, what is the relative merit of the old data compared to new data?" says David Monet, an astronomer with the U.S. Naval Observatory's (USNO's) station in Flagstaff, Arizona, who until 2000 led the scanning of some 20,000 old plates for a searchable online sky catalog. Although he spent nearly 15 years on that project, Monet now thinks historical observations are of little value because of limitations on how accurately the brightness and position of objects can be determined on the images. "The thrill of going back 50 years" is one thing, he says, but "is the science case for doing so strong enough?"

    I want to make a direct analogy with the skeletal biology of Holocene peoples. There are thousands of skeletal remains housed in collections around the world from the last 10,000 years. There are way too many for any one person to study or master, and in fact there are few people who even know the locations of many of the collections. Most of these collections have archaeological or cultural associations of some kind, but unless you are a specialist in a given area of the world, you aren't necessarily going to understand the connections of those associations to time, other regions or peoples.

    In other words, anthropologists have a large and rich record of biological change over the last 10,000 years, but it is very challenging to put together a global picture representing more than a handful of well-developed case studies. I should know -- that's precisely the project I'm most interested in comparing with information about recent genetic changes.

    There are some great projects and particular individuals who have made huge contributions to data collection and accessibility on recent collections. There are in fact too many for me to name individually, and I think we have to remember that those people and projects need more support -- they make so much work possible in our field, which is after all a comparative science.

    Still, we could do a lot more making collections and data comparable to each other and more widely available. This is a time period where, in my experience, collections are exceptionally accessible. The problem is that there are so many things that no one person (or even research group) can keep track of them all. Economizing on time, it is sometimes easier to hit several big collections, which leaves many small collections overlooked. But big collections have their biases. And even in the context of big collections, it becomes very costly to contemplate collecting new data like scans, or warehousing caliper measurements or morphometrics in data archives.

    Anthropology is not like astronomy, where new data collection involves petabytes of telescopic data. Skeletal collections remain our primary data long after they're excavated -- and as ancient genomics becomes more and more possible, the amount of data that we can collect from these skeletal remains will massively increase. So tracking these essentials -- the morphology, scans if possible, the cultural and temporal associations -- will become more and more important to a broader range of scholars.

    UPDATE (2009-05-02): I should mention that the Global History of Health Project is a great example of the kind of systematic study and archiving that could be done in this time period. It's the subject of an article in this week's Science by Ann Gibbons, and I'll be writing more about it later.

    References:

    Bhattacharjee Y. 2009. Stars in dusty file cabinets. Science 324:460-461. doi:10.1126/science.324_460

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Neandertals

For years, I've worked on their bones. Now I'm working on their genes. Read more about the science studying these ancient people.

Denisova

From a finger bone of an ancient human came the record of a completely unexpected population. My lab is working on the science of the Denisova genome.

Acceleration

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Malapa

Just outside Johannesburg, the Malapa site is producing some of the most exciting finds in human evolution. This site is the headquarters of the Malapa Soft Tissue Project.