At long last, the continuation of Neil DeGrasse Tyson’s lecture. Been long enough, hasn’t it? But well worth the wait.
Q & A with Neil is an unforgettable experience. No matter how off-the wall the question, Neil had a ready and witty answer. When asked whether there was any factual basis to the 2012 end-of-world rumors, Neil got down on his knees to explain that the myth is true. There will be a precise alignment of our solar system with the galactic center on December 21st, 2012. “What they left out,” Neil said of those breathlessly predicting doomsday, “is that it happens every December 21st.”
Way to deflate the sails of the doomsday crowd, eh? In case that wasn’t enough, here’s a point-by-point debunk you can use the next time some woo-woo fan in your life starts spouting off about Doomsday 2012.
Higher math intimidates many people, but Neil’s advice to a woman who’s taking the plunge may allay some of those fears. “Math is nothing more than the language the universe is using to speak to you,” he said. “Are you too stupid to learn Chinese? No.
“People don’t view [math] as another language. It is another language. It uses a different kind of alphabet…. View math as a language that allows you to commune with the cosmos.”
That’s a beautiful way to think about it.
As to the rumor that he might become the next head of NASA, Neil said that it’s a “true lie. True that it’s a rumor, but that didn’t make my becoming the next head of NASA true. I haven’t put my hat in the ring.” He sees being on the outside as allowing him to be more nimble. Something tells me that Neil isn’t a huge fan of huge bureaucracies. Besides, NASA probably wouldn’t have let him demote Pluto so easily.
One of the attendees asked him about emotion’s role in science. “Emotions are a good recipe for driving you,” he answered, but warned that scientists have to be ready to abandon their emotions. “Emotion can’t drive data. Refusing to admit data means you’re delusional.”
True, that.
Asked about his scientific heroes, Neil showed no hesitation. “Isaac Newton,” he said. “Once you go Isaac, you never go back.” He paused a beat, and then admitted, “Einstein’s good.” But he believes that if Einstein had been alive in Newton’s day, he would’ve made only about one-third the discoveries that Newton did. “People have made entire careers out of single questions at the ends of [Newton’s] books,” Neil pointed out. Good enough reason to declare Isaac your hero, I’d say.
Some of the other tidbits and awesome quotes from Neil’s Q & A session:
“String theorists aren’t that expensive to keep around.”
Rules in science: “You want your experiment to be finished before you die.”
The fastest rocket we’ve ever sent into space would take 40,000 years to reach the nearest star.
If you were unprotected in space, you’d freeze so hard your ears would crunch off like a potato chip – “But ignoring that complication,” Neil said, “You’d just die of old age” before reaching the nearest star if you were traveling as fast as that rocket.
Pluto is 30% ice, and ice is more than 1/2 of its volume. If its orbit took it close to the sun, it would grow a tail like a comet, which is “no kind of behavior for a planet as far as I’m concerned.”
Titan is so cold, water ice is rocks. Methane is liquid. (Imagine methane oceans lapping at water ice pebbles on a “rocky” beach.)
If you ever get a chance to ask Neil a question, I hope this has prepared you for the answer. He’s not only a fantastic popularizer of science and a damned good astrophysicist, he’s got a light-speed wit. Look him up next time he’s round your part of the world. You won’t be disappointed.
Most of us probably have moments when we wonder just how the hell we made it from bacteria to enormously complex multi-celled entities. Evolution is elegantly simple – almost unbelievably simple. I think that’s why people have such a hard time with it. We’re used to complex things being created by other complex things. It’s hard to imagine simplicity giving rise to mind-boggling complexity.
Well, until you’ve read these two books, it might be.
In Climbing Mount Improbable, Dawkins presents an excellent metaphor. Seen from one side, the mountain seems impassible. There seems to be no way up to the summit. But go round the back, and you find a nice, easy slope that you can amble along. It’ll take a long time, but evolution has bags of it. Three billion years, in fact.
And no one had to make any leaps.
Two things stand out in my mind from these books, because they helped me understand just how we climbed the mountain.
We’ve probably all heard of the sneer that something random like mutation has the same chance of assembling a living creature that a hurricane has of assembling a Boeing 747 while blowing through a junkyard. Dawkins takes off on this theme in The Blind Watchmaker, and introduces the metaphor of the Stretched DC8:
Stretched DC8 macromutations are mutations that, although they may be large in the magnitude of their effects, turn out not to be in terms of their complexity. The Stretched DC8 is an airliner that was made by modifying an earlier airliner, the DC8. It is like a DC8, but with an elongated fuselage. It was an improvement at least from one point of view, in that it could carry more passengers than the original DC8. The stretching is a large increase in length, and in that sense is analogous to a macromutation. More interestingly, the increase in length is, at first sight, a complex one. To elongate the fuselage of an airliner, it is not enough just to insert an extra length of cabin tube. You also have to elongate countless ducts, cables, air tubes and electric wires. You have to put in lots more seats, ashtrays, reading lights, 12-channel music selection and fresh-air nozzles. At first sight there seems to be much more complexity in a Stretched DC8 than there is in an ordinary DC8, but is there really? The answer is no, at least to the extent that the ‘new’ things in the stretched plane are just ‘more of the same.’
Dawkins follows with snakes as his example. Creating a longer snake is a lot like creating a longer DC8 – you just have to duplicate a segment. Big change on the surface, dead easy once you understand what’s going on. And since genes are more a recipe than a blueprint, it’s not surprising that they might sometimes cook up a body with a little more than what the recipe called for. Three eggs rather than two. It might make for a rather sticky cake – or it might be delightfully rich, in which case three eggs will become incorporated into the recipe. Natural selection works with mutations like this all the time, selecting the good and discarding the bad. And after a long time, and many more random changes to the recipe, you’ll end up with something completely different. Trace the recipe back through its various incarnations, though, and you’ll have no trouble seeing how things got from cake to, say, fondue. None of those changes, even the big ones, are any more complicated than duplicating a bit of an airliner to make a longer one.
But what about random mutation? People get hung up on that word, “random.” In Climbing Mount Improbable, Dawkins gets them unhooked:
Even mutations are, as a matter of fact, non-random in various senses, although these senses aren’t relevant to our discussion because they don’t contribute constructively to the improbable perfection of organisms. For example, mutations have well-understood physical causes, and to this extent they are non-random. The reason X-ray machine operators take a step back before pressing the trigger, or wear lead aprons, is that X-rays cause mutations. Mutations are also more likely to occur in some genes than in others. There are ‘hot spots’ on chromosomes where mutation rates are markedly higher than the average. This is another kind of non-randomness. Mutations can be reversed (‘back mutations’). For most genes, mutation in one direction is equally probable. For some, mutation in one direction is more frequent than back mutation in the reverse direction. This gives rise to so-called ‘mutation pressure’ – a tendency to evolve in a particular direction regardless of natural selection. This is yet another sense in which mutation can be described as non-random. Notice that mutation pressure does not systematically drive in the direction of improvement. Nor do X-rays.
So the “random” part of evolution isn’t quite so random as it seems. We don’t have to sit around waiting for a stray mutation to come out of nowhere. All sorts of things cause mutations. Some mutations are more likely than others. And there’s plenty of them available to provide variations for natural selection to choose from. Most of them will be discarded or corrected. A few lucky mutations will be allowed to stay around. And evolution happens.
There’s plenty more where that comes from. Both books together take care of lingering confusions – unless, of course, you’re one of the willfully confused.
Once you’ve read both books, the climb up Mount Improbable seems like no more than a casual summer stroll.
A new telescope that will be able to detect earth-like planets around other stars successfully launched Friday night from Kennedy Space Center in Cape Canaveral, Florida at 10:49 p.m. Eastern time.
The Kepler Space Telescope is the first human tool that will be able to find planets capable of supporting life as we know it.
Its trip into orbit went exactly as planned, with the @NASA twitter feed declaring it, “A perfect launch!”
NASA Headquarters sent out a release at 1:00 am in which Kepler’s project manager drew attention not just to the launch, but the telescope’s ultimate mission.
“It was a stunning launch,” said Kepler Project Manager James Fanson of NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “Our team is thrilled to be a part of something so meaningful to the human race — Kepler will help us understand if our Earth is unique or if others like it are out there.”
[snip]
“She lives! Let’s go find planets!” tweeted S. Pete Worden, head of NASA Ames, which co-managed the project.
Using a sophisticated photometer, Kepler will detect the shadows of planets as they travel across the faces of their home stars in their distant orbits. It may reveal and characterize hundreds of planetary systems, some of which could be like our own, complete with a “twin” of Earth. During its four-year mission in Earth-trailing orbit, the specially designed photometer will focus on and record data from a single swath of stars in our galaxy where stellar systems with habitable planets are likely to exist. The spacecraft will store the data and transmit to Earth about once a week.
To the right there, you can see the photometer. This is an exquisite piece of equipment with a super-exciting mission, and it’s good to see she made it into orbit.
And here’s the completed beastie. Hard to believe that something that looks like mylar wrapping paper stuck in a magazine rack is one of the most sophisticated planet-hunters ever created, eh? But she is:
The Kepler instrument is a specially designed 0.95-meter diameter telescope called a photometer or light meter. It has a very large field of view for an astronomical telescope — 105 square degrees, which is comparable to the area of your hand held at arm’s length. It needs that large a field in order to observe the necessary large number of stars. It stares at the same star field for the entire mission and continuously and simultaneously monitors the brightnesses of more than 100,000 stars for the life of the mission—3.5 years.
The diameter of the telescope needs to be large enough to reduce the noise from photon counting statistics, so that it can measure the small change in brightness of an Earth-like transit. The design of the entire system is such that the combine differential photometric precision over a 6.5 hour integration is less than 20 ppm (one-sigma) for a 12th magnitude solar-like star including an assumed stellar variability of 10 ppm. This is a conservative, worse-case assumption of a grazing transit. A central transit of the Earth crossing the Sun lasts 13 hours. And about 75% of the stars older than 1 Gyr are less variable then the Sun on the time scale of a transit.
The photometer must be spacebased to obtain the photometric precision needed to reliably see an Earth-like transit and to avoid interruptions caused by day-night cycles, seasonal cycles and atmospheric perturbations, such as, extinction associated with ground-based observing.
“Pluto Had it Coming.” Neil deGrasse Tyson does science at Seattle’s Town Hall
When I’m old and gray and suffering from Alzheimer’s, I’ll still remember this lecture. Lecture? Can you call what amounts to stand-up comedy routine by so dry a word as lecture? I think not. It’s like calling Pluto a planet – it lumps Neil in with pompous pontificators, and doesn’t even begin to describe reality.
Neil deGrasse Tyson gives lectures the way the Iron Chef and Emeril Lagasse cook dinner.
If you’ve never seen Neil speak, you’re going to be left as flummoxed as KCTS9 Senior Producer Ethan Morris was upon conducting an interview with him:
Did I think it would be interesting? Yes, I’m a bit of a closet science geek.
Did I think it would be entertaining? Yes, Tyson is animated and enthusiastic about the universe, enough to make him a regular guest on programs like the Daily Show with Jon Stewart and the TODAY Show.
Did I think we would be practically rolling on the floor laughing? No, and boy was I wrong.
That’s about how I felt. I figured the lecture would be interesting, informative, and at least a little entertaining, but I really didn’t expect the rib-fracturing hilarity. If all popularizers of science were this outrageously fun, we wouldn’t have to worry about a damn thing. American Idol and its ilk would be reduced to competing for time slots with infomercials at three in the morning. And science wouldn’t just be for geeks anymore.
The photo below captures some of Neil’s dynamism as a speaker. If you view lectures as an opportunity to catch up on sleep, you’re out of luck.
So, can someone who fills his lectures with anecdotes of death threats, zingers, one-liners, and political snark really educate you about science? Oh, yes he can!
Neil’s plugging his book The Pluto Files, which I had absolutely no interest in reading until now. When all the drama happened over ZOMG THEY DEMOTED PLUTO!1!!!1!! Planet, dwarf planet, my first and eleventy-first thoughts were “what-the-fuck-ever. Yawn.” Not yawning anymore.
This stuff is important. You’ll see why once we’ve reached the end of this series.
Neil began by setting the stage. Back around 2000 or so, when they were spiffing up the Hayden Planetarium, they were looking for different ways to present the solar system. Instead of the usual lineup, they decided to group like with like, creating a “family photo of the solar system,” as Neil described it. They put together the portraits: terrestrial planets, the asteroid belt, gas giants, Kuiper objects. And as they assembled the photos of various family members, they realized something: Pluto didn’t really fit with the terrestrial planets at all. It was small, icy, with an incredibly odd orbit. Where to put it?
Well, they had the Kuiper objects just sitting there staring at them. Imagine Neil leaning into the audience, sharing the process of dawning realization with suitably dramatic delivery: “Small – kinda like Pluto. Icy – kinda like Pluto. Odd orbits – kinda like Pluto.” No use trying to escape inescapable conclusions. Into the Kuiper objects Pluto went.
Neil received one letter about it over the next year, from a young boy named Will G. “You are missing planet Pluto,” Will wrote. “This is what it looks like.” He helpfully included a blue crayon drawing of Pluto. Priceless. And Neil, of course, milks that letter for all its comedic worth.
The point he and his colleagues at the Hayden Planetarium were making was this: “The name of the fifth planet from the sun – that’s not science.” In the best traditions of another Neil (Gaiman), they were being contentious, shaking things up. They were moving away from facts and getting into science.
Only Will G. really noticed. Until one year later, when the New York Times ran a story on its front page. January 22nd, 2001, Neil arrived to a full voicemail box and overflowing emails. “Something is awry,” he said, and picked up the Times.
On page one, sharing space with dimpled chads in Florida and a (now-debunked) story about Iraq rebuilding weapons, there was a headline:
Pluto Not a Planet
With all of the drama going on in the world, the Times had chosen to highlight the Hayden Planetarium’s demotion of Pluto. “Only in New York!” Neil milks this for it’s full dramatic effect. Apparently, all it takes for science to get front-page treatment is to redefine the solar system.
“That’s when the hate mail began,” Neil said. Pissed-off kids wrote him demanding him to put Pluto back. But of course, Neil and his fellow astrophysicists weren’t about to do that. Pluto’s demotion had been in the works for a long time. “Pluto had it coming.”
Neil loves throwing down on Pluto, but he also makes another excellent point: “Pluto had finally found family, and we think it’s happier there.” To understand why, it helps to know a little about the Kuiper Belt, and about another demoted planet.
This illustration makes it clear: Pluto really has found its family among Kuiper Belt objects. The Kuiper Belt itself is a region out beyond Neptune, where no planet large enough to sweep its orbit clean has formed. It vaguely resembles the asteroid belt – a lot of detritus left over from the formation of the solar system. But unlike the asteroid belt, it’s bodies aren’t rocky, but composed largely of frozen methane, ammonia and water. If Pluto got knocked out of its orbit (a distinct possibility in such a crowded place), and ended up swinging close to the Sun, it would develop a tail just like a comet. Did you know that? I didn’t – not before Neil.
I also didn’t know that when you describe Kuiper Belt objects as “icy bodies” around young children, you might get the reaction Neil once did: a shocked gasp, and a whispered, “Are there really dead bodies out there?”
Pluto’s not the first planet to get a demotion. Back in 1801, the astronomical world was abuzz with excitement. William Herschel had discovered Uranus – “Yur-in-iss, that’s how you pronounce that word” – and, based on a now-disproved law called the Titius-Bode law, astronomers began eagerly searching for a new planet they knew had to be there. On New Year’s Day in 1801, Giuseppe Piazzi found it, and named it Ceres.
Ceres ended up in textbooks as a planet for the next fifty years. But you won’t find Uranus there – unless you’re looking for George. Herschel had named it for the King of England. “I find the concept of a planet named George disturbing,” Neil told us. So did the rest of the astronomical world. But you can’t piss off Great Britain. Eventually, a compromise was reached: George was renamed Uranus, but instead of its moons being named after Greek gods, they were named after Shakespearean characters instead. This is the sort of thing that happens when astronomy runs headlong into international politics.
The Roman pantheon (after which all planets are named) is big, but possibly not big enough to contain all of the “planets” being discovered. By 1820, there were 11; shortly after, another dozen joined the crowd. Astronomers realized something was awry. These erstwhile planets were so tiny they appeared as pinpricks of light in telescopes. Eventually, in 1850, astronomers gave up calling them planets and classified them as asteroids – starlike, after their appearance in telescopes – instead.
When you compare Ceres to other planets in the Solar System, the reason for its demotion becomes crystal clear:
(Image filched from here; links to Bad Astronomy where I first saw it. Both sites commend your attention.)
If your vision is good, you might see the specks that represent the relative sizes of Ceres, Pluto, and fellow Kuiper Belt object and planetary contender Eris (2003 UB313). Important objects they are: planets, they are not.
But the search for planets wasn’t over. Newton’s laws of gravity described planetary orbits to a T, but the math just wouldn’t compute for Uranus. There were only two explanations: either there was another large body out beyond Uranus, or Newton’s laws didn’t work that far from the Sun. “That was the question of the day,” Neil says. They honestly didn’t know. But they crunched the numbers, predicted where a planet should be, and had a look – and there they found Neptune, right where Newton’s laws said it would be.
This will eventually take us to the discovery of Pluto, its rise and its fall. But we’re going to save that tale for next week. Neil packs a lot of science and a lot of history into a half-hour presentation. There’s no way I can do his delivery justice in prose – I’d have to be dancing across a stage like a Hindu god while delivering one-liners like a veteran comedian – but I can at least spend the time to do the science justice. And yes, we’ll be seasoning it liberally with Neil’s words o’ wisdom.
In the meantime, I’ve embedded a video clip of Neil that does a rather good job of capturing his wit, wisdom and wildness. This is actually something discussed at the lecture: Neil has endless fun with the doomsday crowd predicting the end of the world (again) in 2012. I’ll have even more for you next week – clear your calendars.
The quotes I’ve thrown in and the video I’ve included must have convinced you that Neil deGrasse Tyson is the most awesome science popularizer in the country. Should you ever get the chance to see him in person, do it. It doesn’t matter if you have to sell your firstborn, lie to your boss, or risk a relationship to get the night free. Every lover of science needs to see Neil at least once.
Drag along a disinterested friend. I guarantee that friend won’t stay disinterested for long. And by the end, even the most passionate Pluto partisans among us may forgive Neil for demoting it.
Ron Britton, one of the Masters o’ the Smack-o-Matic, recreated this wonderful poster that really says everything one needs to say when arguing evolution’s case. He says:
I’ve always liked this poster. The evidence for evolution goes way beyond the fossils, but this poster summarizes the fossil evidence quite well. One of the things creationists are always claiming is that there are “no transitional fossils!” Well you’re staring right at one!
All of you evilutionists should know that transitional fossil by sight. For the rest of you, we’ll be revealing its identity shortly.
If the creationists were right, I wouldn’t be able to write this post for lack of fossils. In fact, I have the exact opposite problem. Here’s a partial list of transitionals. Keep scrolling. And scrolling. And scrolling. And once you’ve finally reached the bottom of that partial list, keep something in mind: it was last modified in 2001, before many of the spectacular finds I’ll be highlighting in this post were made.
That’s a hell of a lot of transitional fossils the creationists have to pretend don’t exist, isn’t it?
I’m currently re-reading Richard Dawkins’s wonderful book The Ancestor’s Tale, and before we dive into the transitionals themselves, I want to share several insights I’ve gleaned. One of the major confusions, and the hardest thing to explain to folks who don’t know much about evolution, is how species transition from one to another. People tend to see evolution as a series of discrete steps instead of cumulative, gradual changes. That’s why you get IDiots demanding to know why there’s no cat-dog in the fossil record.
Dawkins handles this rather nicely:
It is true that when we look at living species, we expect members of different genera to be less alike than members of different species within the same genus. But it can’t work like that for fossils, if we have a continuous historical lineage in evolution. At the borderline between any fossil species and its immediate predecessor, there must be some individuals about whom it is absurd to argue, since the reductio of such an argument must be that parents of one species gave birth to the child of the other. It is even more absurd to suggest that a baby of the genus Homo was born to parents of a completely different genus, Australopithecus. These are evolutionary regions into which our zoological naming conventions were never designed to go.
When we consider transitional fossils, then, it’s best to remember that they’re capturing a moment in time. They’re like snapshots. There were plenty of individuals both before and after the transition that were shading from one thing to another.
The diagram below captures the essence of this fairly well, albeit without the shading. Notice the relationships. We’re not walking a straight line from Australopithecus to Homo erectus to Homo sapiens here.
Here’s another evolutionary fact to keep in mind. Dawkins, tracing humanity’s ancestry back to a small shrew-like mammal he calls Henry, shows how species diverge:
Long-distance ancestry, of a particular group of descendants such as the human species, is an all-or-nothing affair. Moreover, it is perfectly possible that Henry is my ancestor (and necessarily yours, given that you are human enough to be reading this book) while his brother Eric is the ancestor of, say, all the surviving aardvarks. Not only is it possible. It is a remarkable fact that there must be a moment in history when there were two animals in the same species, one of whom became the ancestor of all humans and no aardvarks, while the other became the ancestor of all aardvarks and no humans. They may have met, and may even have been brothers. You can cross out aardvark and substitute any other modern species you like, and the statement must still be true. Think it through, and you will find that it follows from the fact that all species are cousins of one another. Bear in mind when you do so that the “ancestor of all aardvarks” will also be the ancestor of lots of very different things besides aardvarks (in this case, the entire major group called Afrotheria… which includes elephants and dugongs, hyraxes and Madagascan tenrecs).
By now, you should be getting the feeling that finding a transitional fossil isn’t necessarily like filling in a gap on the family tree. The gaps in our fossil record aren’t so concise as, say, Grandmother, blank spot, granddaughter. In the case of a genealogical chart, we know there’s one and only one way to fill in that blank: with a mom. In the fossil record, it’s more like a series of “moms,” all a little bit less grandmother and getting closer to granddaughter. And, just like mothers can give birth to more than one granddaughter (or grandson), one species can give rise to several, who eventually become so different from one another that it’s hard to comprehend that they were ever related at all, even distantly. (I’m sure many of us feel that way about our distant ancestors, comes to that – I’m sure that if I ran into the cave-dwelling couple who, 20,000 years ago, started the lines that eventually led to me and, say, the Kiowa, we wouldn’t have plenty to talk about. We’d seem absolutely alien to each other. Yet, there we are – related. They’re my ancestors, while not a single Kiowa is. Interesting, eh?)
Now that you’ve been hedged about with all of the proper caveats and such, I feel comfortable showing you a pretty straightforward evolutionary line.
We were fishes once, and young. At the bottom, you see an undeniable lobe-finned fish, Eusthenopteron. These darlings had all of the necessary equipment to start us on the road to land – nostrils (in their case, internal), “a distinct humerus, ulna, and radius (in the fore-fin) and femur, tibia, and fibula (in the pelvic fin).” Those bits probably sound familiar, especially to those of you who have broken any of those bones.
Onward we go, through Panderichthys, whose fins are still very much fins but showing clear signs of headed toward tetrapod limbs, and whose spiracle, a nifty little bit of anatomy that allowed it to breathe water through the top of its head, eventally became our ear’s stirrup bone. We’re getting closer to land, and then, ZOMG, there’s a gap!!1!11!
You can see it in that red bit in the line, there. Acanthostega used to be our next fossil in line, and it had true limbs, complete with really-real toes. How the hell did we get there from the mostly-finny fins of Panderichthys? And that’s where one of the greatest demonstrations of the predictive power of evolution comes in:
The scientists who discovered Tiktaalik made a threefold prediction, based on evolutionary theory: that such a creature would exist, that it would be found in rocks in a certain location, and that it would be found in rocks of a certain age. They went to this area explicitly because other primitive tetrapods had been found there, and searched in Late Devonian strata because more fish-like creatures were known from earlier strata and more tetrapod-like creatures were known from later strata. And all three of these predictions were borne out by the evidence.
Tiktaalik, it turns out, has plenty to tell us about the transition from water to land, which is why it’s the perfect subject for Ron’s evolution poster:
Meticulous studies of the internal structure of the cranium from several fossil fishapods, T. roseae, reveal the step-wise process that morphological changes followed as terrestriality evolved in tetrapods. [snip]“The braincase, palate and gill arch skeleton of Tiktaalik have been revealed in great detail,” reports Jason Downs, a research fellow at the Academy of Natural Sciences who is the lead author of the study. “By revealing new details of the pattern of change in this part of the skeleton, we see that cranial features once associated with land-living animals were first adaptations for life in shallow water.”
Well, that’s what makes transitionals so interesting, innit? They demonstrate how we got here from there. And if we have a here without a there, we know that all we have to do is go look – there will be a there there. In fact, don’t be surprised if we find several fossils that have paleontologists arguing over whether they’re Tiktaalik or Panderichthys – there’s bound to be some hard-to-classify versions that represent transitions between the two. Many fossils have led to constant quibbling, reshuffling, redefining, and a variety of interpretations that might drive you absolutely nuts until you realize that kind of uncertainty is a good thing. Here’s Richard Dawkins again:
If you think about it, we should be worried if there
was not disagreement over the divisions. On the evolutionary view of life, a continuous range of intermediates is to be expected.
Conversely, of course, we shouldn’t panic if we can’t find those intermediates right off – we’re lucky, between the vagaries of decomposition, critters scavenging other critters, and chemical and mechanical weathering, not to mention the grand finale of plate tectonics, that we have any fossils at all. There are some transitionals we may never find, simply because they didn’t get preserved. Put it like this, though: we know they lived. You wouldn’t claim you didn’t have a great-great-great-great-grandmother just because all the records about her got destroyed in fires and floods and various other mishaps, now, would you? She obviously existed – otherwise you wouldn’t be here. Same thing with the transitionals.
And there’s always the chance we’ll come across her records in unexpected places, which would leave those arguing against her existence looking rather foolish. Check out these beauties, found just within the last decade:
The latest Nature reveals a new primitive mammal fossil collected in the Mesozoic strata of the Yan mountains of China. It’s small and unprepossessing, but it has at least two noteworthy novelties, and first among them is that it represents another step in the transition from the reptilian to the mammalian jaw and ear.[snip]In us, the old articular and quadrate bones have completely lost their role in supporting the jaw as a joint and instead have become imbedded in the middle ear of mammals, suspended with the stapes between two delicate membranes to specialize in conducting sound vibrations to the inner ear. What does the hearing apparatus look like in Yanoconodon?
I’m going to be cruel and force you over to Pharyngula to find out.
Now, Matt Friedman from the University of Chicago has described a new transitional fossil that is one of the most dramatic yet. Its name is Heteronectes (meaning “different swimmer”) and it’s a flatfish, but not as you know it.
You’ve probably eaten flatfish before but tasty fillets of plaice, sole or halibut give few hints about their extraordinary physical specialisations. They are fish that live on their sides and their flat profiles make them both efficient hunters and difficult prey. For other fish, lying sideways would give one eye a useless view of sand but flatfish have adapted accordingly. Their fry resemble those of other fish but as they grow, one of their eyes makes an amazing journey to the other side of its head. The adults look like they’ve swum out of a Picasso painting.
But Heteronectes is a half-committed flatfish. Like modern representatives, its skull is asymmetrical and one eye has begun migrating to the other side of its head. But it hasn’t made it all the way round and stops near the midline without crossing to the other side. No living flatfish has eyes arranged in such a way. We couldn’t have wished for a better intermediate form – it’s a marvellous missing link between the standard fish body plan and the distorted visages of flounders and soles.
Ed Yong’s post is wonderful, but don’t stop there – click the photo for some classic snark from the University of Chicago’s news room. Take that, creationists!
Not a bad haul from an evening’s digging, eh? If this post got you as excited over transitional fossils as it should have, do Ron Britton a favor – copy that wonderful Tiktaalik poster at the beginning and post it on your own blogs. It nearly went extinct, but, as Ron says, ” If we can get enough members of this species onto the internet, it will reestablish itself as a self-sustaining population.”
Conservation is always a worthy goal. Especially when the message is so damned true.
That’s no small thing, although she was tiny – about the size of a seven year-old. She was a big deal here in Seattle this Valentine’s Day, when a passel of people walked over to see her at the Pacific Science Center, and got to thinking about her legacy. I’ll have a lot more to say about her in a future installment. For now, we’re going to take a photo journey through the pieces of our past the exhibit touched on.
The exhibit has a replica of the Laetoli Footprints. 3.6 million years ago, some of Lucy’s kin, Australopithecus afarensis, walked through volcanic ash, and left us a record of their bipedal meanderings. There’s something extraordinary in seeing the footsteps of those who walked before us. Bipedal posture seems so uniquely human that it leaves an immediate impression. Other becomes us in an instant. Suddenly, you can picture yourself walking side-by-side with a little ape-like ancestor who wouldn’t have to strain her back to hold your hand. There’s something special in that. It brings paleoanthropology alive.
Lucy almost wasn’t found. When you see fossils in a museum, they’re already extracted from their rock matrix, easy to see, sometimes stained dark. You begin to think that the dark brown patina is the actual color, but fossils are products of their surroundings, and blend in. And if it wasn’t for the instincts of a sharp-eyed paleontologist, Lucy wouldn’t be here in Seattle today:
Then, on the morning of November 24, 1974,[3] near the Awash River, Johanson abandoned a plan to update his field notes and joined graduate student, Tom Gray from Texas State, in taking their Land Rover to Locality 162 to search for bone fossils.[9]Both Johanson and Gray spent a couple of hours on the increasingly hot arid plains, surveying the dusty terrain, then Johanson decided on a hunch to make a small detour on their way back to the Land Rover to look at the bottom of a small gulley that had been checked at least twice before by other workers. At first sight there was virtually no bone in the gulley, but as they turned to leave, a fossil caught Johanson’s eye; an arm bone fragment lying on the slope.
“She occupies a pivotal place on the human family tree,” said Donald Johanson, the American paleoanthropologist who, with his colleagues, discovered the fossil in 1974 near the northern Ethiopian community of Hadar. “We now know that one of the first significant things our ancestors did was to stand up, to walk on two feet instead of four.”
The exhibit helps resolve a debate that’s been raging since well before I was born: was it the brain or the bipedalism that came first? Lucy says we got on our own two feet before we started on the big brain portion of our program. Below, you’ll see a chart showing the brain sizes of many of our ancestors and close cousins. Lucy’s posture wasn’t terribly different from ours, but her brain capacity certainly was. A modern human boasts a cranial capacity of about 1100-1700 cc. Hers would have been between 375-500 cc. Einstein she wasn’t – at least, not compared to us.
Upright posture, it seems, came first, freeing our hands for other tasks. And those free hands got busy manipulating the world, which helped lead to bigger and bigger brains.
I wasn’t thinking all that much about brains, although I’d had my fun with the display of water bottles that could be flipped upside-down to drain into the skulls of a chimpanzee, A. afarensis, and homo sapiens. It’s the knees that caught my attention. I didn’t know a damned thing about knee angles until I saw a display up against the wall demonstrating what upright posture does to the shape of the knee. It’s fascinating:
Femurs of upright walkers and ape
Leg of ape Quadrupedal animals like apes, have femurs in which the ball joint, the part that joins the pelvis, sits directly over the inside of the knee. The angle subtended by the femur at the knee in quadrupedal walkers is less than that of bipedal walkers.
Leg of Australopithecus afarensis This diagram shows the femur with the same shape and structure as that of modern humans, but it is a little shorter. It subtends the same angle at the knee as that of a modern human and the inner bump of the knee joint is larger than the outer one. This shows that this hominin was also a bipedal walker.
Leg of modern human This modern Homo sapiens bone shows the structure of the femur of an upright walker or bipedal animal. The ball joint, the part that joins the pelvis, sits directly over the outside of the knee. The angle subtended by the femur at the knee in bipedal walkers is greater than that of quadrupedal walkers. This results in the inner bump of the knee joint being longer than the outer bump.
Pretty amazing, isn’t that just?
That posture does interesting things to the pelvis. And hers looks remarkably like one of ours, aside from not having to be so wide to accommodate big-brained babies. You can see the similarity in the picture at right:
Comparison of three female pelves over the course of the last three million years. The pelvis of “Lucy” (Australopithecus afarensis, around 3.2 million years old) on the left, the new Gona pelvis (Homo erectus, about 1.2-1.3 million years old) in the middle, and a modern human female (Homo sapiens) on the right.
That’s a spectacularly clear evolutionary progression right there, isn’t it just? It’s really hard to stare at Lucy’s hips, pelvis and knees without being dumbstruck by the similarities.
But that’s nothing compared to walking up a long, sloping corridor filled with hominid skulls, and realizing that some of these folks would’ve looked a lot like us.
Kneeling down, looking in the eye sockets of some of those skulls, seeing the shapes become so close to our own, gave me an eerie thrill. I could see the sutures in a Neanderthal’s skull. I could see the softening of the brow ridges as time went on, the increase in brain size, the changes in cheeks and jaw. We think of our ancestors and cousins as ape-like brutes, but a lot of them, like Neanderthal, were nearly identical. Seeing those skulls all lined up makes you realize how close we are to where we came from.
And, strangely enough, little Lucy’s skull, chimp-like as it is, also has some incredibly human features. Her jaw, her teeth, aren’t as different from us as you might expect.
There’s a sculpture of her there, nearly the first thing you see when you walk into the room where her bones lie spotlit in the dark. She stares over her shoulder, almost coquettish, and utterly adorable. This image to the right was taken at a bad angle – it doesn’t capture the slight smile, the serene joy in her expression. She’s definitely an ape, still, but she strongly foreshadows the humans to come.
It’s a delightful sculpture that makes Lucy more than just a collection of remarkable bones. You want to slip your hand into hers, let her tug you into her world. You get the feeling that the two of you would relate on a level a little closer than humans and chimps. She has a lot to tell us, and in a way, it’s too bad that all we can listen to are her bones.
But what incredible bones they are.
The first thing that strikes you is how small they are. The rib bones are no wider than my finger. Her vertebrae are tiny. And her pelvis is a delicate, beautifully curved structure that doesn’t look strong enough to bear an upright body. She was under four feet tall, which is a bit of a jolt when compared to the size of her legend.
The second thing you notice is her pallor. The bones are a silvery-tan, with only hints of darker brown here and there, almost shimmering against the stark black of the case they have her in. It’s incredible that those pale bones were ever found in the pale dust of the Ethiopian desert.
It does inspire awe, gazing down at bones that are nearly four million years old, that have so many human characteristics that the ape-like ones fade into the background. Even an amateur like me can see how much she had to say about who we are, what we were, and how we got from there to here.
She’s an inspiration. She’s glorious. She’s earned both of her names: Dinkenesh, which means “Wonderful one,” and Lucy – because, for all that she’s lying under glass in a museum, it truly seems she is “Lucy in the Sky with Diamonds.”
Go see her, should you get the chance. She’ll tell you something wonderful.
Alas, due to various and sundry distractions, I haven’t been keeping on with the science blogs as I should. For this Sunday’s Sensational Science, I do believe we’ll need to remedy that situation.
But first, I just want to point out something: blogs, and the internet in general, have been a boon to science. Instead of having to wade through expensive peer-reviewed journals at the library, getting misinformed by newspapers and magazines, or having to wait for new editions of books to incorporate cutting-edge research, we now have a place where scientists and science journalists share the very latest with a wide audience quickly and inexpensively. This is getting science into the hands of the masses in a major way, and it is teh awesome.
Just look at all the goodness that hit my screen this evening. Hot, fresh science, delivered up in bite-sized morsels. Or, in this instance, images of gigantic snakes:
Just wait — this one will be featured in some cheesy Sci-Fi channel creature feature in a few months. Paleontologists have dug up a fossil boa that lived 58-60 million years ago. They haven’t found a complete skeleton, but there’s enough to get an estimate of the size. Look at these vertebrae!
[Dana looks. Dana thinks, “Forget about news reports of snakes eating dogs and toddlers – were this thing alive today, we’d be reading headlines like ‘Sumo Wrestler Swallowed by Super-sized Snake’.”]
[snip]
The extinct beast is estimated to have been about 13 meters long, weighing over 1100 kg (for us Americans, that’s 42 feet and 2500 pounds). This is a very big snake, the largest ever found.
The size isn’t what mattered to me when I read this post. It was the fact they can use this snake to estimate the temp at the time. And, reminded that snakes (like other cold-blooded critters) can get larger when it’s warmer, this has given me a disturbing glimpse at unmentioned hazards of global warming.
I don’t have a snake phobia – yet.
(As an aside, how long do you think it’ll be before some creationist pounces on this as the remains of Leviathan or the serpent from Eden, eh?)
Ginormous boa constrictors apparently weren’t enough this week. From Brian Switek, we get a blast from the past:
Standing before the Linnean Society in 1839, the celebrated British anatomist Richard Owen delivered a detailed description of a strange new creature. Owen called it Lepidosiren annectans, an African relative of an eel-like animal that was found by the Austrian explorer Johan Natterer in the depths of the Amazon jungle in 1837. The naturalist sent two specimens back to the Vienna Museum where they were quickly described by Leopold Fitzinger under the name Lepidosiren paradoxa.
Fitzinger considered the organisms to be “perennibranchiate reptiles”, meaning that it was a primitive amphibian that did not undergo metamorphosis. Instead, according to the author of a helpful Living Age column, it remained “a gill-breathing, muddy, fishlike groveller, all the days of its life.” The animal Owen had was different,* but it was similar enough to Natterer’s specimen to allow for a close comparison of this important new genus.
Right. When time travel comes available, the ancient Amazon is right off my itinerary.
Do you need a good transitional whale to whack IDiots over the head with? Brian has the goods:
Just announced in the journal PLoS One, Maiacetus was a member of the Protocetidae, an extinct group of early whales that beautifully illustrate an important phase of whale evolution. Previously known members of the group include Rodhocetus and Protocetus from Pakistan and Georgiacetus from the southern United States, the latter animal illustrating that this group included the first whales able to cross oceans.
Unlike Basilosaurus, these whales still had hips that were attached to their vertebral column. Many members of this group probably swam by undulating their spine while paddling with their limbs, perhaps similar to the way an otter moves through the water. The fusion of the hips to the spine limited their range of movement, but it did allow them to support themselves on the shores of the estuaries and coastlines they inhabited.
These are generalities, of course, because not all members of the Protocetidae were the same. In particular they were marked by differences in limb proportions, and Maiacetus fits snugly into the continuum of anatomical types. Rodhocetus, for example, has very large hind limbs ended with flat, paddle-like feet. Protocetus, by contrast, had much smaller hind limbs that were probably not very important to locomotion; its tail was more important to its swimming style. Maiacetus is closer to Rodhocetus in form but its hind limbs are smaller and do not show the same adaptations for hind-foot propulsion. What does this mean?
Well, for one thing, it means I get to laugh harder at creationists than usual.
Turning from paleontology to biology, we find Abby Smith ecstatic:
Im probably going to do several posts on this paper (lots of cool findings), but I want to get this one bit of good news out there before some ass ‘science journalist’ mangles it :P
Haaland et al followed about 2,000 (2,000) discordant couples (one partner was infected with HIV-1, the other was not). At set points in time, they tested the non-infected individual for the prescience of HIV-1 and antibodies to HIV-1, hoping to catch transmission right when it happened so they could characterize what goes on, so we can figure out how to stop it.
Read on for the reveal. This is why genetics are important, kids.
Finally, Efrique shows us what the Game of Life (which I played for untold hours back when I had it on my desktop) and Belousov-Zhabotinsky reactions have to do with each other. I can’t extract this one – you’ve gots to go see it to believes it.
I enjoy living in geologically interesting places. That wasn’t always the case – there was a Bad Moment in elementary school when we were learning about volcanoes, and if I’d had any choice in the matter, I would’ve chosen to move somewhere dead boring. Staring out the classroom window at the enormous shield volcano within spitting distance and realizing that dormant in no way means extinct just as the teacher is showing films of how shield volcanoes are made makes one a bit thoughtful. Especially when the film includes scenes from Iceland’s attempt to stop a lava flow from engulfing a town.
Over time, however, I found my fears replaced by fascination. Arizona is a geologist’s dream. So is Washington State. Granted, many of our more interesting formations are covered by abundant vegetation, but you can still catch a glimpse of the bones of the earth here and there. We have active volcanoes to play with. The whole state is a hodgepodge of continental remnants and island arcs plastered on to the North American Continent any-old-how, as you can see in the illustration below.
And we’ve got what Arizona hasn’t got: a tectonic plate complete with spreading ridge and subduction zone sitting right off our coastline. How awesome is that? Extremely.
The Juan de Fuca Plate’s been on my mind for a few days now. On Thursday, tectonic hanky-panky led to a few exciting moments as a magnitude 4.5 earthquake struck the Seattle area. On Friday, I came nose-to-stone with a chunk carved out of a volcanic vent from the Juan de Fuca Plate’s spreading center. They’re both of a piece. Things in this area are on the move.
In the illustration to the left, you can see the bounds of the plate (including the Explorer and Gorda Plates, which are sometimes included when talking about the Juan de Fuca Plate as a whole). To the west lies a spreading zone much like the Mid-Atlantic Ridge. To the east lies the subduction zone, where the plate dives under the huge North American Plate, creating the Cascadia Subduction Zone.
The Juan de Fuca Plate wasn’t always this tiny. Back when the dinosaurs who inspired Jurassic Park were roaming the earth, the Juan de Fuca Plate was part of the ancient and enormous Farallon Plate. How enormous? Put it like this: Juan’s sibling plates stretch from Canada (the Explorer Plate) all the way down to Central and South America (the Cocos and Nazca Plates, respectively).
The Farallon Plate built up all of that lovely mountainous geography the West is so well-known for, and the Juan de Fuca Plate’s living up to its parent’s reputation. Its subduction under the North American Plate has given rise to the Cascade Range, including the Cascade volcanoes that occasionally make life very interesting for local residents, and the Pacific Ranges of Canada. If you’ve ever marveled at the beauty and power of those volcanoes, you now know whom to thank.
The subduction zone doesn’t just fuel volcanoes, however. It also gives rise to some fairly interesting earthquakes. You’ve got your plain-vanilla shaking, of course – the kind like our recent event, which is over in a moment and means that something that was building up tension just went twang. But studying this subduction zone also led scientists to realize there’s another type of quake that can go on for weeks:
In 2001, the continuous GPS network Pacific Northwest Geodetic Array, aided in discovery of slow-slip across the Cascadia Subduction Zone. Previously undetected by seismic networks, these slip events exhibit regular recurrence intervals thus changing current understanding of earthquake behavior. Since this time, definitions for this newly discovered phenomenon have evolved. At first, the term “silent-earthquake” was employed to illustrate the absence of a seismic signature. Subsequent investigations and recent discoveries have led to a change in characterization. Now these slow-slip events are defined as eposodic tremor and slip (ETS).
In short, an ETS is a discreet time interval (episode) of relative tectonic plate movement (slip) coupled with high frequency seismic energy bursts (tremor). ETS usually last for around a few weeks duration as opposed to regular earthquakes where energy is released within seconds to minutes.
If you want to talk about the cutting edge of geology, love, this is it. We’ve got your cutting edge right here.
Let’s move away from the subduction zone, though, and talk a bit about the spreading ridge, which to me is a more interesting animal. We normally think of such ridges as being “mid-ocean,” considering perhaps the most well-known one is the Mid-Atlantic Ridge. But there’s no rule confining ridges to the middle of the ocean – they occur wherever two plates are diverging, allowing magma to well to the surface. The jury’s still out (as far as I know) on whether the ridges drive the conveyor belts of the plates or whether it’s the subduction zones pulling them apart. But we do know that these are areas of fascinating volcanic activity.
It almost looks like ruins of an ancient arched city, doesn’t it? That’s just Nature, building pillars of lava and capping them off with lava bridges. Had things gone a bit differently, those would have been lava tubes. Lava does amazing things underwater – it doesn’t just stop at pillow lava.
The bit of undersea vent I saw came from a complex called Faulty Towers (and how much would you like to bet the person who named that was a John Cleese fan?). You might be surprised to know what one of these vents looks like when it’s high and dry. It’s a fissured chunk of basalt sparkling with copper, zinc and iron sulphides. Somehow, you just don’t think of a vent being sparkly, but they’re veined with precious metals precipitated out of the super-heated water flowing through them, so sparkly they are.
Move over, Pyrolobus fumarii. A new entry for the record books has just been discovered. The hottest organism known to man has been isolated from a thermal vent deep in the Pacific Ocean.
The previous record-holder, P. fumarii, could live at temperatures as high as 113 °C (235 °F), well above the boiling point of water. But the new microbe, for now called “Strain 121,” thrives at 121 °C and can even survive for two hours at 130 °C.
The new organism is also unusual because it relies on iron to digest food and produce energy. Such organisms show promise in generating electricity from waste products and in removing radioactive metals from the environment.
“No one had ever seen a bug like this before,” says Derek R. Lovley of the University of Massachusetts in Amherst, who along with colleague Kazem Kashefi reported their discovery in Science. Researchers believe that many high-temperature microbes rely on iron to grow, but none had ever been isolated or cultured until now.
Isn’t that incredible? Not only do we have a bite-sized tectonic plate complete with speading ridge and subduction zone sitting right off our coastline, we have life no one had ever seen before as well! The Juan de Fuca Plate’s more than just a geologist’s playground – there’s plenty of fun for the whole scientific family.
For myself, I’m just awed by the fact that I live right next door to things that I once considered exotic and far away. There’s nothing more sensational than knowing that some of the most incredible undersea scenery is practically right in your own back yard.
As an SF author trying to grasp enough science to make her world work, I’ve read a crapton of science books. Some of them have been meh, some mkay, and some teh awesome. There are authors whose books I return to endlessly, not merely because of the science, but because of the way they wield their words. They’re not only scientists, but prose poets. They get across the grandeur and excitement of science. They delight in the absurd and bask in the beautiful. They make me think, but more than that, they make me dream.
I’ll introduce you to a few of them today. They’ve not only written books, but articles worth reading.
One of the most important things scientists can do is popularize it, bring it within the grasp of people without degrees. These authors have done that. We owe ’em one.
Steven Pinker, experimental psychologist, Harvard University
During one of my many extravaganzas in the local used bookstore, I ran across a book called The Language Instinct. I’d fallen in love with linguistics because of Tolkien, and here was a man who explored the evolution of language. Brilliant! The book came home with me. And I know I’ll probably hear screams from those of you who think evolutionary psychology is so much bunkum, but I enjoyed it immensely. Steven’s subject matter isn’t simple, but he makes it seem so. He’s got a wonderful sense of humor and rapier-sharp insight. One of my favorite lines comes from another book of his, The Blank Slate: “It is precisely because one act can balance ten thousand kind ones that we call it ‘evil’.” Say what you will about evolutionary psychology, but he’s speaking absolute truth there.
I found two fascinating articles by Steven. In “My Genome, My Self“, he takes us on a whirlwind tour of what genes mean to personality, and then his adventure in personal genome sequencing:
Our genes are a big part of what we are. But even knowing the totality of genetic predictors, there will be many things about ourselves that no genome scan — and for that matter, no demographic checklist — will ever reveal. With these bookends in mind, I rolled up my sleeve, drooled into a couple of vials and awaited the results of three analyses of my DNA.
Then he provokes some thought by exploring “The Moral Instinct.” This one might be of enormous good use in debates with frothing fundies.
Michio Kaku, theoretical physicist, City College of New York
Working at the bookstore brings a lot of books to your attention you might not have noticed otherwise. Such was the case with Beyond Einstein. What did this guy mean, beyond Einstein? Who could possibly be beyond Einstein?
Such was my introduction to string theory. And I fell in love. I understand it even less than I understand quantum mechanics, but damn it, Michio makes it exciting. He takes you right out on the cutting edge, and sends you careening through realms of possibility you didn’t even know exist. Beyond Einstein? You betcha! Or at least, there’s the possibility we’re getting closer to that Theory of Everything Einstein spent the rest of his life pursuing.
Michio also wrote a book called Visions, which is an absolute boon to an SF writer who has a little trouble extrapolating the possibilities for the future. He’s got a lot more books out there, all of them intriguing, all of them bringing incredibly complex subjects within the reach of ordinary folk.
His excitement about the cosmos continues to bubble over as he advises NASA to “Follow the Methane!”
The recent discovery of methane on Mars is more than a curiousity. It could be a game changer.
For the last three decades, NASA’s Mars exploration program has been based on a single mantra: Follow the water. Where there is water, there might be life. So far, this strategy has come up empty handed. But now, NASA might have to change course and follow the methane.
Seems like good advice to me.
Oliver Sacks, neurologist, New York City
I had no idea what to think of a book with a title like The Man Who Mistook His Wife for a Hat. Written by a man whose last name was Sacks, no less. I shelved copies of it many times before intrigue finally got the better of me and I finally bought the thing.
And I was in another world.
Oliver explores damaged minds, showing us the bizarre and fascinating things that happen when the wetware is nonfunctional (h/t Connie Willis). And he does it with glorious warmth, compassion, and wonder. This is a man who adores his work, adores the people he works with, and helps us view even the most damaged people as individuals who are more than the sum of their disorder. And the man who mistook his wife for a hat? Visual agnosia, brought on by a brain tumor.
In “The Abyss,” Sacks discusses music, amnesia, and a profoundly amnesiac musician named Clive:
Though one cannot have direct knowledge of one’s own amnesia, there may be ways to infer it: from the expressions on people’s faces when one has repeated something half a dozen times; when one looks down at one’s coffee cup and finds that it is empty; when one looks at one’s diary and sees entries in one’s own handwriting. Lacking memory, lacking direct experiential knowledge, amnesiacs have to make hypotheses and inferences, and they usually make plausible ones. They can infer that they have been doing something, been somewhere, even though they cannot recollect what or where. Yet Clive, rather than making plausible guesses, always came to the conclusion that he had just been “awakened,” that he had been “dead.” This seemed to me a reflection of the almost instantaneous effacement of perception for Clive—thought itself was almost impossible within this tiny window of time. Indeed, Clive once said to Deborah, “I am completely incapable of thinking.”
Richard Fortey, paleontologist, London
When I was studying plate tectonics, I ran across a book called Earth: an Intimate History. And intimate it is. It reads more like a biography than geology, although you come away knowing more about geology than you’d ever imagined you could. The Alps take on a completely different meaning when you know how they formed. You discover that England and America have far more in common than our political history: the Appalachians were once part of Scotland. Other wonders await. I don’t think I’ve ever quite been so absorbed by geology. Richard Fortey turns out to be one hell of a biographer.
He’s also an enthusiastic fossil man, having written more than one book regarding life on earth. In the following YouTube video, he introduces us to his favorite fossil:
And in “The Ego and the ID,” he gives Intelligent Design the thorough spanking it deserves.
I can assure you from experience that the authors I’ve explored here are well worth savoring. Here are two that I haven’t yet had the pleasure of settling in with yet, but plan to in the very near future:
In “The Beasts Within,” University of Chicago paleontologist Neil Shubin explores what made him fall in love with his inner beasties:
I’ve come to love my inner fish. My inner worm, jellyfish and sponge too. And I can tell you exactly when I first recognized this infatuation: in September 2003, the year I was pressed into teaching human anatomy to first-year medical students at the University of Chicago.
And astrophysicist Neil deGrasse Tyson gives us “The Cosmic Perspective” and reminds us not to forget each other as we pursue the stars:
Yet the cosmic view comes with a hidden cost. When I travel thousands of miles to spend a few moments in the fast-moving shadow of the Moon during a total solar eclipse, sometimes I lose sight of Earth.
You know what, Neil? I think Professor Fortney can help you with that.
Alas, spelunking the Science Daily website turned up no news in breakthrough treatments for evil Aunty Flow. Between her antics and the goings-on in Gaza, I didn’t have time to put together anything coherent. But plucking biomedical news at random from Science Daily will give you at least a little sensational science for your Sunday.
As bacteria resistant to commonly used antibiotics continue to increase in number, scientists keep searching for new sources of drugs. One potential new bactericide has now been found in the tiny freshwater animal Hydra.
The protein identified by Joachim Grötzinger, Thomas Bosch and colleagues at the University of Kiel, hydramacin-1, is unusual (and also clinically valuable) as it shares virtually no similarity with any other known antibacterial proteins except for two antimicrobials found in another ancient animal, the leech.
Hydramacin proved to be extremely effective though; in a series of laboratory experiments, this protein could kill a wide range of both Gram-positive and Gram-negative bacteria, including clinically-isolated drug-resistant strains like Klebsiella oxytoca (a common cause of nosocomial infections). Hydramacin works by sticking to the bacterial surface, promoting the clumping of nearby bacteria, then disrupting the bacterial membrane.
Scientists at Albert Einstein College of Medicine of Yeshiva University have identified a small intracellular protein that helps cells commit suicide. The finding could lead to drugs for combating cancer and other diseases characterized by overproduction of cells.
The research was led by the late Dennis Shields, Ph.D., a professor in Einstein’s Department of Developmental and Molecular Biology for 30 years, who died unexpectedly in December.
In response to stress or as a natural part of aging, many cells undergo programmed suicide, also known as apoptosis. Cancer cells often become immortal and dangerous by developing the ability to suppress apoptosis.
A decade ago apoptosis was thought to be directed solely by the nucleus and mitochondria of cells. Dr. Shields’ laboratory was the first to show that a cellular organelle known as the Golgi apparatus also plays a role in apoptosis.
The Golgi package proteins and other substances made by cells and direct them to their destination within the cell. A protein called p115 is vital for maintaining the structure of the Golgi. In earlier research, Dr. Shields’ group demonstrated that the Golgi’s p115 protein splits into two pieces early in apoptosis and that the smaller of these protein fragments—205 amino acids in length—helps to maintain the cell-suicide process.
Ever since the 1966 Hollywood movie, doctors have imagined a real-life Fantastic Voyage a medical vehicle shrunk small enough to “submarine” in and fix faulty cells in the body. Thanks to new research by Tel Aviv University scientists, that reality may be only three years away.
The blueprints for the submarine and a map of its proposed maiden voyage were published earlier this year in Science by Dr. Dan Peer, who now leads the Tel Aviv University team at the Department of Cell Research and Immunology. The team will build and test-run the actual “machine” in human bodies. Dr. Peer originally developed the scenario at Harvard University.
Made from biological materials, the real-life medical submarine’s Fantastic Voyage won’t have enough room for Raquel Welch, but the nano-sized structure will be big enough to deliver the payload: effective drugs to kill cancer cells and eradicate faulty proteins.
New research reveals the brain activity that underlies our tendency to “follow the crowd.” The study, published by Cell Press in the January 15th issue of the journal Neuron, provides intriguing insight into how human behavior can be guided by the perceived behavior of other individuals.
[snip]
Dr. Klucharev and colleagues hypothesized that social conformity might be based on reinforcement learning and that a conflict with group opinion could trigger a “prediction error” signal. A prediction error, first identified in reinforcement learning models, is a difference between expected and obtained outcomes that is thought to signal the need for a behavioral adjustment.
The researchers used functional magnetic resonance imaging to examine brain activity in subjects whose initial judgments of facial attractiveness were open to influence by group opinion. Specifically, they examined the rostral cingulate zone (RCZ) and the nucleus accumbens (NAc). The RCZ is thought to play a role in monitoring behavioral outcomes, and the NAc has been implicated in the anticipation and processing of rewards as well as social learning.
The study authors found that a conflict with the group opinion triggered a long-term conforming adjustment of an individual’s own rating and that conflict with the group elicited a neuronal response in the RCZ and NAc similar to a prediction error signal. Further, the magnitude of the individual conflict-related signal in the NAc correlated with differences in conforming behavior across subjects.
In research published in the advanced online publication of Nature Genetics, researchers have identified a genetic defect for common epilepsies on chromosome 15. A subset of patients with epilepsy lacked a certain part of this chromosome. Further studies on patients from the USA confirmed this finding. The loss of small chromosomal segments, called microdeletions by geneticists, has previously not been connected with common disorders that also include many types of common epilepsies.
Dr. Ingo Helbig, University of Kiel and Department of Neuropediatrics at the University Medical Center Schleswig Holstein, Germany, is first author on this research study: “So far, we didn’t know that microdeletions, loss of entire chromosomal segments including several genes, can also be a cause for common diseases. This finding will help understand why people suffer from common disorders including epilepsies.”
Up to three percent of the population experience epileptic seizures and one percent suffers from epilepsy, which is characterised by recurrent seizures. The researchers hope that understanding how this genetic defect leads to epilepsy will help develop new drugs against seizures. So far, most genes for epilepsy were only found in rare form of epilepsies. However, hereditary factors are long known to play a much larger role, contributing to many common forms of seizure disorders. Hence, the discovery of the 15q13.3 microdeletions in common epilepsies is an important milestone.
The DREAM gene, which is crucial in regulating pain perception, also seems to influence learning and memory. This is the result of studies carried out by researchers in Seville (Spain) and Vienna (Austria). The new findings could help explain the mechanisms of Alzheimer’s disease and yield a potential new therapeutic target.
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Josef Penninger, meanwhile scientific director of IMBA, the Institute of Molecular Biotechnology of the Austrian Academy of Sciences in Vienna, continued to wonder what other surprises DREAM might have in store. In a collaborative effort with neurobiologists from the University Pablo de Olivade (Seville) he devised experiments to follow up on the previous findings. A team of scientists under Ángel Manuel Carrión subjected DREAM-less mice to numerous neurological tests and analyzed their memory skills. The results were striking: without DREAM, mice were able to learn faster and remember better. Fascinatingly, the brains of aged mice (18 months) showed learning capacities similar to those of very young mice.
Thus, DREAM turns out to be a genetic candidate for explaining old age dementia. Even a causal connection to Alzheimer’s disease seems plausible.
Studies published in mid 2008 suggest that the devastating condition may be related to Calcium regulation gone awry. The accumulation of amyloid plaques in brain cells, usually blamed for Alzheimer’s, might be a consequence of the Calcium-imbalance rather than the culprit for the disease.
And Calcium regulation is also responsible for tuning the activity of the DREAM-gene. Calcium homeostasis may thus be the link between pain perception, learning and memory. This is supported by observations of patients suffering from chronic pain: very often their ability to memorize is strikingly reduced and they need a lot more time to learn than individuals without pain.
Not a bad haul for just sticking your hand in and pulling out a handful of articles, eh? The last two photos are Easter eggs – click and enjoy!
