a citizen’s journal by Thomas Nephew

Looking for chameleons? Use a satellite

Posted by Thomas Nephew on 3rd July 2004

inset from figure on NASA Earth Observatory site

To me, this is extremely, triumphantly, hopping-up-and-down cool: scientists from the American Museum of Natural History used archived museum records, satellite imaging, computer mapping (a.k.a. GIS), and genetic algorithms to discover unsuspected chameleon habitats in Madagascar. From NASA’s “Earth Observatory” web site, Madagascar’s Chameleons:

Raxworthy and his colleagues have been developing predictive models that are based on a combination of satellite observations of environmental characteristics — such as land cover from NASA’s Moderate Resolution Imaging Spectroradiometer and topography from the Shuttle Radar Topography Mission — and museum records of locations where biologists and naturalists have spotted different chameleons over the years. […]

The scientists were initially surprised that for four species, the models predicted that the species lived in areas where no specimens had ever been documented before (bottom row, colored ovals). … [and] eventually discovered that far from being a mistake, these overlapping “over-predicted” areas actually pointed to locations where new species of chameleon were likely to be discovered.

(The “overpredicted” areas are circled in the figure above.) In the accompanying article Uncovering Chameleons, writer Rebecca Lindsey explains:

To come up with ecological niche models for Madagascar’s chameleons, Raxworthy and his colleagues [used] a genetic algorithm nicknamed GARP (which stands for Genetic Algorithm for Rule-set Prediction).

GARP evaluated the models based on the number of chameleon location points from the original museum records it correctly predicted, as well as by its ability to identify places where the species would not be found. GARP kept evolving the mathematical rules of the survivors and deleting the losers until it produced a single model that it couldn’t improve upon—survival of the fittest.

The real world soon provided confirmation — of a sort — for the satellite image-museum data-GARP process:

“At the time this modeling project was going on, we were also identifying chameleon specimens we had collected on previous expeditions to Madagascar,” explains Raxworthy, “so the discoveries were going on in parallel universes, so to speak. Then one day I realized that one of the new species we had discovered actually came from an over-predicted area on one of the model’s maps. It finally occurred to me that maybe each of those areas that we thought were model foul-ups could actually be the location of new species”.

As the team identified more of the specimens, the number of newly identified species began to mount. In all, the over-predicted areas identified by the models were home to seven new species of chameleon that had never been documented by scientists before. (emphasis added)

My rudimentary evolutionary theory suggests to me the newly identified species occupy ecological niches that might well have otherwise been occupied by those Raxworthy et al focused on (e.g., Brookesia stumpfii, see figure above). It would be interesting to know just how divergent — genetically and phenotypically — the newly discovered species are from those ‘erroneously’ predicted to be there by the GARP process: close cousins? Convergent evolution?

The method Raxworthy et al developed (or at least convincingly demonstrated, I’m not up on this) has obvious applications in ecology and conservation biology at minimum. But it might have applications in sociology and political science as well — I imagine the thing being modeled doesn’t absolutely have to be an evolving entity of its own for GARP etc. to be worth a try. At any rate, an article about all this has been published in Nature,* and I may actually make my way to some university library or other to xerox it.

Waah. Those are the toys I want to play with. Hmmm… maybe I can.

* Christopher J. Raxworthy, Enrique Martinez-Meyer, Ned Horning, Ronald A. Nussbaum, Gregory E. Schneider, Miguel A. Ortega-Huerta2 & A. Townsend Peterson. Predicting distributions of known and unknown reptile species in Madagascar. 2003. Nature 426, 837-841.

UPDATE, 7/6: More genetic algorithms in the news: a German-American team used the technique to optimize network server performance. Via Gary Farber.

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Now you tell us

Posted by Thomas Nephew on 3rd March 2004

Rover reveals Mars was once wet enough for life; sadly, the fine print here means NASA’s discovery may have come too late for millions of Americans.

This observer wonders whether NASA intentionally delayed its discovery just to serve the interests of corporate America.

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Present at the creation: M17 “Swan” Nebula

Posted by Thomas Nephew on 29th April 2003

Present at the creation: M17 “Swan” Nebula

Department of Unprovable Assertions

Flying home from my dad’s birthday (75!), I picked up a “Scientific American” in the news kiosk, intrigued by the “Parallel Universes” cover story. Among the simpler arguments presented was that (1) the available evidence apparently supports the intuitive notion that space is infinite (not “curved” so that a latter-day Magellan would return to his starting point), (2) there seems no reason to suppose the space beyond our viewing horizon (speed of light * age of universe) isn’t full of stuff, too, so that (3) there’s enough stuff to eventually make a duplicate galaxy with a duplicate you sitting in it reading a duplicate blog post by a duplicate me. This is called a Level I parallel universe (where “universe” is actually just “everything you can see,” which is much less than “everything there is.”)

Looking at that image above, or just at ants making their way across my lawn, I have trouble believing in that: there just seems too much detail, whimsy, and beauty for anything so vast as my universe to be repeated. On the other hand, it might be comforting to believe the whole universe is so dumb it would allow a parallel “Survivor” show somewhere 10^(10^28) meters away. At that rate, my own dumb habits would be a little easier to put up with.

But the idea seems seems to imply that once you’ve arranged all the atoms etc. identically, the whole process leading to the arrangement and the whole process following it must be identical. Otherwise, what accounts for the difference before or after the moment when the two universes are identical? Yet if the two universes are in different places, that can’t be. So something seems wrong to me, and it’s probably that I’ve stayed up too late again.


UPDATE, 10AM: OK, thinking about it a little more, there’s no need to assume two identical universes got identical the same way, any more than two paintings had to be completed with the same series of brushstrokes to be identical. So Level I universe cosmology is safe from my late-night criticism. I’m also not sure the two identical universes would have to stay identical once they got that way: at the periphery of the two identical universes, observers would see different things, and would thereby become different: different memories, science, etc. This would work its way to the center of each identical universe. Therefore: never mind.

UPDATE, May 14: I just noticed that Chad Orzel discussed the article and my questions yesterday. Thanks!

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Posted by Thomas Nephew on 4th April 2003

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.01% chance the big news this week will be from Arecibo, Puerto Rico…

Posted by Thomas Nephew on 16th March 2003

A UC Berkeley press release reports that SETI@home screensaver folks like me (1003 units completed, thank you very much) will have something to look forward to: a followup on the 150 most promising signal sources so far. The project divides up chunks of radio telescope data and distributes it to subscribers like myself; a dedicated screensaver analyzes the data and returns assessments to the SETI@home headquarters at UC Berkeley about the likelihood of the data representing part of an intelligent signal from elsewhere in the universe.

“This is the culmination of more than three years of computing, the largest computation ever done,” said UC Berkeley computer scientist David Anderson, director of SETI@home. “It’s a milestone for the SETI@home project.” […]

To acknowledge the 4,287,000-plus users who have analyzed radio data, the SETI@home team will post on its Web site the names of those participants who flagged the candidate signals as a result of data analysis on their home computers. Each candidate signal was analyzed by several people, because SETI@home sends the same data to more than one person to double-check results.


“I give it a one in 10,000 chance that one of our candidate signals turns out to be from ET,” said [SETI@home chief scientist] Werthimer, who will head for Puerto Rico on March 16.

The final results of the March 18-20 re-observations at the Arecibo radio telescope observatory will be available within two to three months, but scientists will know right away if they’ve got a promising candidate.

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Gone workin’, back at the end of the week

Posted by Thomas Nephew on 3rd March 2003

See you then. Meanwhile, check out the excellent blogs on the left, including two recent additions, “Dr. Frank’s” Blogs of War (which is much better than that might sound), and Eve Tushnet’s

Anticrepuscular spookiness
There’s a fairly straightforward explanation for this phenomenon (click the image, via “Astronomy Picture of the Day,” to find out).

I just wonder if I would have been inclined to consider a “natural” explanation (or even had the vocabulary for it) if I’d seen this in prehistoric times. Even with the clues like direct opposition to the sunrise or sunset, it might have taken quite an effort of will to not ascribe it to something supernatural or divine.

Plus, who’s got the time with that panther chasing you? Aaeee! Gotta run!

Comic relief

  • Cannot find weapons of mass destruction
  • The Saddam and George show
  • French jokes, more French jokes, and yet another French joke. I disapprove! Yet I laugh!
  • spoofs 1, 2, 3, 4
  • Richard Cohen muses, “My immersion in popular culture has left me saddened. I no longer can avoid concluding that there is something off about Michael Jackson.”…via the tireless Gary Farber, “Idle words” (“Brevity is for the weak”), Jeff Jarvis, Gil Shterzer, my Metro readings, and … somebody or other. Good night! Drive safely!
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    Goodbye, au revoir, auf Wiedersehen…

    Posted by Thomas Nephew on 1st March 2003

    Pioneer 10, the probe sent past Jupiter and Saturn and then on into deep space, has stopped sending detectable signals.

    The famous plaque to the right was installed as a message to any intelligent being who discovers it. The meanings of the symbols are explained here; among the interesting tidbits are:

    The radial pattern (4) will help other scientists locate our solar system in the galaxy. The solid bars indicate distance, with the horizontal bar (5), denoting the distance from the Sun to the galactic center. The shorter solid bars represent directions and distances to various pulsars from our Sun, and the ticks following them are the periods of the pulsars in binary form. Pulsars are known to be slowing down and if the rate of slowing is constant, an other-world scientist should be able to roughly deduce the time Pioneer was launched.

    I’m reminded of the “Star Trek” episode “The Changeling,” in which an Old Earth deep space probe named “Nomad” is rediscovered by the Enterprise and, in a strangely affecting scene, recounts the story of its odyssey (and transformation) to Spock.

    It’s vanishingly unlikely, I suppose, that anyone or anything out there will see the plaque and try to understand it. I wonder if there’s a science fiction story about that… Anyway:


    More images here, and here’s a link to “Pioneer Odyssey,” an account of the Pioneer 10 and 11 voyages, which visited Jupiter, Saturn, and beyond. A fantastic accomplishment, with a fantastic memorial to it sailing out into the universe.

    (Via Gary Farber)

    EDIT, 3/16/07: Images stored to photobucket, set to larger size, rearranged slightly, and linked to WikiMedia Commons pages. (NASA’s site has mislaid the image URLs at the moment.)

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    Newsrack weekend grab bag

    Posted by Thomas Nephew on 9th February 2003

    • Those bad boys from Huawei Technologies of Shenzhen, China have apparently been at it again. First noted in these pages for selling high-tech communications equipment to Iraq, they now face a lawsuit by American communications equipment heavyweight Cisco Systems. Cisco Systems charges that Huawei has been ripping off Cisco designs wholesale — right down to manuals copied word-for-word, and bugs identical to those in Cisco’s proprietary “IOS” operating system. This suggests a whole new way to undo Saddam: create buggy American technology, sell it to the Chinese, and let nature take its course. “Anti-aircraft sites reporting all clear, Your Immensity!”
    • Aziz Poonawalla was riding high in his SUV lately, and should be answered presently. It seems to me both he and the good folks at Reason have focused — of necessity — on Gregg Easterbrook’s less important points in that writer’s (not-so-)recent “Axle of Evil” piece for The New Republic. Yes, Gregg makes some stupid points, e.g., pretty soon more drivers schooled in the gentle arts of Third World car driving will be acquiring SUVs in America. The real points against SUVs are that they deserve none of the free regulatory ride they’ve been getting, and they are a disproportionate danger to *other* drivers on the road. Easterbrook may have padded his article with atmospherics about intimidating design and so forth, but I suspect even here he’s got a point, just not one that is easily verified. I would bet that you’d find SUV drivers are consuming their sense of collision safety with more aggressive driving habits, rather than simply reveling in Junior’s added safety back there in his child seat. But I wouldn’t know how you could go about proving it. I just feel like I see it on a daily basis.
    • I updated my item about the Columbia and manned space exploration with an e-mail from Mr. Kevin Drum. Kevin pointed out that he wrote that he felt skeptical of manned space exploration before the accident, and thus wasn’t using the accident as an excuse. My apologies. Regarding the manned space program, I can agree with Charles Krauthammer (“It’s time to dream higher”) that the shuttle and space station by themselves are not an adequate space program; for the expense and risk involved, I’d much rather see real space exploration and colonization, of the moon or Mars for starters. I continue to believe that humans will be a critical part of the science and the politics of space and planetary exploration, so I believe there must remain an American manned space program.
    • Longtime readers may have noticed a small redesign on the left. I’ve added a new “blogs elsewhere” list, featuring the well-known Bjorn Staerk of Norway and “Salam Pax” of Iraq, as well as the perhaps less well-known but equally engaging “Miranda,” a Russian Jewish woman living in Munich, and Gil Shterzer and one Ms. Imshin of Israel. Welcome aboard! I’ll be looking for more world bloggers from time to time; of necessity, I’m restricted to blogs written in English and German, a topic that came up recently. I don’t actually disagree with Bjorn that much about the need for more English communication from European bloggers. As I commented,

      I’d modify Bjorn’s challenge to suggest that more German bloggers […] post comments in English-language blogs, possibly with back-links to an English post on their own blog.

      A less visible change is on the “archive” page, where I’ve added a few “selected posts”, but mainly a “thank you list” of some of the folks who’ve been good enough to include me on their list of links, and the best I can do for now in “trackbacks” to people who’ve linked to selected items of mine.

    • Received a “reciprocal linkage” request, i.e., “I’ll link to your blog if you link to mine”; no, thank you. Either you like what I write about and how I write it, and you link to my site, or you don’t. For my part, all four quadrants of the “like/dislike your writing” and “link/don’t link to your site” can occur; I’m looking for a combination of reasonably good writing and a reasonable breadth of views about politics in my list of links. I’ll confess I’m disappointed when I get “de-linked,” i.e., no longer featured on someone’s list of interesting blogs, but I recognize that sooner or later, everyone will certainly find more interesting writing and/or more that they agree with elsewhere.At any rate, thank you, dear readers, for reading this blog from time to time.

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    When the going gets tough, get your news at Kid’s Post

    Posted by Thomas Nephew on 5th February 2003

    Meant to mention that I happened to check out the weekly Washington Post “Kid’s Post” section on Monday. Naturally, it was all about the Columbia.

    What got me was that this section did a better, sparer job of reporting than the front page section did. Simple questions were asked and answered, with “we don’t know” used up front and without much elaboration. After reading the single page, you would know about 90% of what there is to know from the front section, and you wouldn’t “know” 90% of what was fluff or speculation from the front section.

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    You can’t win if you don’t play

    Posted by Thomas Nephew on 4th February 2003

    That, in a nutshell, is why I think the United States must maintain a manned space program. I’ve been following a lot of commentary about the Columbia accident. In particular, Kevin Drum (“Calpundit”) has written a series of noteworthy posts on the subject, sharing his own thoughtful ambivalence about manned space exploration. From Drum’s first post:

    As much as I dearly love the dream of manned space flight and the colonization of other plants, the sad truth is that there’s simply no compelling reason to send humans into space on a regular basis.To perform scientific experiments? Nope. It turns out that there is virtually no scientific research that requires human handholding except the study of human adaptation to space itself. So the only reason to send humans into orbit is….to see how well humans hold up in orbit.

    To explore Mars? Ditto. It can be done by unmanned probes just as well.

    To set up space factories? Unfortunately, nobody is much interested in commercial uses of space. Adequate vacuums can be set up on Earth quite nicely, thank you very much, and weightlessness turns out to have very few commercial possibilities.

    To colonize other planets? Why? In case we bomb each other into the stone age here on Earth? How long would a moon colony last if it didn’t get regular supply visits from Earth?

    Space tourism? Maybe, but if this is the only reason, then NASA needs to get out of it. Let the private sector do the job.

    In a later post, Drum writes:

    I love the idea of manned space flight myself. If my income tax form had a box that allowed me to contribute an extra $100 to a government program to colonize space, I’d probably check it off. Unfortunately, though, I suspect the “symphonies and ballets” analogy is a pretty good one. And like the civic arts, manned space flight probably ought to be consigned primarily to the private sector, where it will be funded by enthusiasts and rich philanthropists. Maybe Bill Gates would contribute a couple billion dollars.

    Today, Drum turns a William Burrows quote in the L.A. Times on its head, writing:

    But turn that around and see how this sounds instead:

    If anything good is to come out of the cause for which the Titanic passengers died, it should be a resolve that it is humanity’s destiny to inhabit the ocean’s depths, its sea floor, and beyond.

    Domed colonies on the floor of the sea were a science fiction staple of Jules Verne’s time, but today it sounds quaint and old fashioned. Why would we bother?

    That’s the problem with manned space flight. I’m not opposed to it because it’s dangerous, or because the government shouldn’t be in the business of basic research, or because we should be spending the money fighting poverty instead. I’m opposed because some dreams just don’t pan out as well as others. Manned space flight today is like the domed sea colonies of 1900: cool sounding, but ultimately not very interesting.

    Metaphors are treacherous things, of course. Needless to say, the Titanic’s passengers were not seeking to inhabit the ocean’s depths. Their purpose was no higher than the proverbial chicken’s crossing the road: to get to the other side. The Columbia’s crew’s mission was more profound than that.

    Drum is right: from a short-term practical perspective, and other than the circular reasoning of manned space flight research, there’s probably little to recommend manned space flight over safer, cheaper alternatives. Except this: in space, human presence will always be nine tenths if not 99,999 one hundred thousandths of the right to be there, and to have a say in how the exploration and exploitation of our solar system will proceed. You can quote me the UN Outer Space Treaty and the like until you’re blue in the face. We won’t matter if we’re not there.

    In truth, this has always been one of the main forces driving exploration, and it’s not a stupid one. You plant your flag first, and worry about economic feasibility later. I’d guess that most of the first hundred voyages to the New World lost money … or worse. I’m all for getting out of the way of private sector space exploration. One example of how to do this is provided by the X-Prize competition, a great idea to encourage low-cost private manned space flight. But I’m not for leaving space exploration solely up to the vagaries of private enterprise and economics, not for now. Drum’s own list of objections to manned space flight convinces me of that.

    Whether we continue with manned space exploration or not, others will. I’d prefer that Americans be part of that, rather than watch from the sidelines as countries like Europe, Russia, China, or India eagerly take up the effort Drum suggests we drop. Even in the nicer world we wish for someday, it will remain true that those with the skills, and capital and courage to actually be in space will have right of way over those who merely send up probes and satellites. Whatever is of value up there, from lunar or asteroid mining to prospects yet unknown, will accrue mainly to those with the foresight to put humans up there to oversee the machinery and stake the claims.

    Finally, it’s not altogether corny to suggest that the United States benefits by being the kind of place where the Kalpana Chawla’s of the world want to come. There are people bolder, less calculating, more risk-taking than either Mr. Drum or myself; people who instinctively know it’s important to be there, not just watch it on a screen from Mission Control. It’s likely that the Columbia had seven of them aboard. The world will always have such people; I’d like to make sure some of the ones in space are from this country, on this country’s dime.

    I mourn the loss of the Columbia and its astronauts. And therefore I don’t at all support using the Columbia accident to cut short the very careers and aspirations that these people chose. We need more like them, whether they’re flying space shuttles or better space vehicles. The payoff from their work and experience will come someday. In the meantime, I think it verges on short-sightedness to insist that manned space flight be anything than what it is: exploration, pure and simple, without the prospect of or need for immediate returns. The payoffs could be enormous; they could be crucial. It’s best to stay in the game.


    UPDATE: Kevin Drum e-mailed to say,

    In one of my pieces I tried to make it clear that my view is *not* based on the Columbia tragedy. […] In fact, I’d almost hate to see us pull back now because it would seem like we were doing it for the wrong reason. That’s the problem with not doing the right thing from the start: when a crisis comes, you then have to continue with the old failed policies because anything else looks like caving in.

    (link added). Since I implied the Columbia tragedy was why Kevin felt as he did (“don’t… support using the Columbia accident to cut short…”), I’m setting this record straight.

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