The venom-spitting dinosaur in Jurassic Park may have been fictional, but in a great case of life imitating art, scientists have discovered evidence of a real venomous dinosaur that walked the earth in China over 120 million years ago. Sinornithosaurus is the first confirmed venomous dinosaur, but there is evidence that venom is even older than this most recent discovery--that creatures from up to 500 million years ago could also have been venomous. These ancient venomous creatures are giving us reason to believe that, evolutionarily speaking, not being venomous may actually be more noteworthy than being venomous.

David Burnham, a paleontologist at the Kansas University Natural History Museum, was hunting for raptor fossils in rural China when he and his colleagues stumbled across a new fossil skeleton with grooved teeth and an inexplicable gap in its skull. They puzzled over what these two clues could mean. And then one day, while examining the skulls of venomous komodo dragons, it suddenly clicked. The cavities in the raptor skull very closely resembled areas in the komodo dragon skull reserved for their venom glands. Burnham began to wonder, was it possible that this ancient raptor was also venomous?

My, what big teeth you have! The Sinornithosaurus fossil specimen bares its teeth. Image courtesy David Burnham.

Further investigation revealed that everything Sinornithosaurus (the newly named raptor species) would need to be venomous was there. The spaces in the skull would have made room for prominent venom glands, along with a drainage canal leading into the mouth and muscles to help pump out the venom. But this dinosaur's venom-delivery mechanism was rather primitive. Unlike many modern snakes with long fangs in the front of their mouths that can forcefully eject venom at their prey (remember spitting cobras?), Sinornithosaurus had teeth with grooves for delivering venom that sat at the back of its mouth. Burnham suspects that over evolutionary time, tooth material closed in around the groove and migrated towards the front of the mouth, leading to something more closely resembling a cobra's fangs. The grooved teeth mean that unlike its fictional Jurassic Park counterpart, Sinornithosaurus had to chew the venom into its prey, probably using it more as a stunning tool than a killing one. A handful of modern snakes, unsurprisingly called "rear-fanged snakes," have retained the Sinornithosaurus-style grooved teeth.

Discoveries like Sinornithosaurus give scientists more decisive clues into the evolutionary history of venom. But we have reason to believe that venom is much older than even the dinosaurs. The conodont, an eel-like creature that lived almost 500 million years ago, had the same kinds of grooved teeth found in Sinornithosaurus and other primitive venomous creatures. And the evolutionary influence of the conodont is far from slight: it gave rise to all fish and most vertebrates.

There are more than 41,000 described species of spider, and over 99% of them are venomous. Mercifully, there are only four small groups of spiders whose venom is lethal to humans, but insects beware: Spider venom can inflict a cocktail of unpleasant symptoms, from full-body convulsions and paralysis to spontaneous cell death that dissolves your body while you're still conscious. With so many species and so much time to diversify, spiders have developed methods to capture and kill just about every kind of insect prey out there. And now, humans are developing ways to take advantage of diverse spider toxins to create pesticides that kill insects without harming humans or the environment.

Image Courtesy Bruno Santos

Greta Binford spends most of her time doing research at Lewis and Clark College in Oregon, but when she's not in the lab, she can be found hunting down the deadly brown recluse spider everywhere from peculiar haunts like the basement of a Goodwill store in Los Angeles to the mountains in their native Peru. They are generalists that will eat pretty much anything that walks by, but other spiders are much more specialized. Tarantulas live in holes and only capture things that come near their dwellings; orb weavers catch insects in flight. A few species spit toxic glue at their prey; others dash underwater and bite fish. Most interesting of all to researchers like Binford is that all these spiders' venoms reflect the diversity in how and what they catch.

Jamie Seymour is hunting shadows. Box jellyfish--some of the most terrifying animals on the planet--are completely invisible in water, so the best Seymour can hope to find are the shadows they project onto the shallow ocean floor. He keeps a stealthy eye out for flashes of shadows on the sand beneath his boat just a few feet off the northern Australian coastline. When he thinks he's spotted something, he tosses a large plastic bin overboard in hopes of pinning his prey. Clad in thick rubber armor to protect himself from the box jelly, Seymour hops out of the boat to investigate his catch.

The box jellyfish inside the bin is roughly the size of a squared-off basketball. Though it is called a jellyfish and looks much like one, it is technically a member of a slightly different species. Chironex fleckeri has a startling 24 eyes, six facing each direction. On its base are 60 tentacles roughly eight feet long that bear a striking resemblance to fettuccine. Creeped out yet? If not, here's the final nail in the coffin: These animals can kill a human in about two minutes, and we don't entirely know how. Not to mention that a box jellyfish sting is probably among the most painful ways to die.

A signpost at a beach in Cape Tribulation, Queensland, Australia warning of the presence of the box jellyfish Chironex fleckeri and others. Image courtesy TydeNet, licensed under Creative Commons.

Seymour is a professor of biology at James Cook University in Australia, and has spent much of his professional life studying and tracking box jellies. He's devised a way to follow these animals by capturing them in his plastic bins and using surgical glue to attach small tracking devices to their skin. The glue only lasts a few days, but it's enough time to make some startling discoveries.

Among the first surprises: Box jellies are fast. They can swim at speeds up to four and a half knots--that's just under the speed of an Olympic swimmer. When they swim, their tentacles shrink from as long as ten feet to as short as two feet to help reduce resistance. In other words, unless you're Michael Phelps, don't count on being able to outrun one of these guys.

Even more shocking than their speed is when box jellies stop all together. Sleep is extremely unusual in invertebrates, especially ones that are composed of 96% water. Seymour's colleagues went so far as to call him nuts when he proposed the idea that box jellies sleep, but the data is clear: Box jellies sink to the bottom of the ocean and snooze whenever it's dark outside. Why is this significant? First and foremost, it gives the box jellies a chance to hide from their turtle predators, who are lucky enough to be one of the few creatures immune to box jellyfish venom. But it also gives them a chance to grow. Box jellies grow about two to three millimeters every single night, putting on layers like a tree. Their metabolisms have to run like V8 engines to fuel that kind of growth, so sleep gives them a chance to sit still while they expand in size.

When Bruce Young walks into a room filled with spitting cobras, he elicits a terrifying response. "They just love to spit at me," says the professor at the University of Massachusetts at Lowell. Spitting cobras have evolved the ability to hurl venom at the

A staring contest with a spitting cobra. Image Courtesy Biju Joshi

eyes of predators, debilitating and often blinding animals many times their size from up to ten feet away. So when it came time for Young to choose a target to use in order to study how cobras hit their targets' eyes with such accuracy, it seemed only natural to choose... his own face. Because, really, what else would you choose?

Young was studying the evolutionary history of cobras when he began to notice an interesting byproduct of the cobras' constant spitting in his direction. The venom trails that dried on the glass walls of the cobra tanks formed varied and beautiful geometric patterns. Cobras store venom in glands hidden just behind their eyes, and when they spit, they flex powerful muscles that force the venom out through long, thin fangs. But unlike the cobra's target, the fangs can't move. How could these complex patterns of venom form, and even more impressively, how could the cobras hit their targets with an accuracy rate over ninety percent? Young reasoned it must have something to do with head movements, but he wanted to know more.

Optical illusions and magic tricks can illuminate how the brain's visual systems are wired; NOVA scienceNOW's Magic and the Brain showed how. But can we learn about language processing in the same way? Colin Phillips thinks so. Phillips studies "linguistic illusions" to learn more about how our brains process words in real time. Here are a few linguistic illusions to try out, based on some that he shared with us at the AAAS. Skip to the continued link for explanations.

More people have been to Russia than I have.

The key to the cabinets are on the table.

While she was taking classes full time, Russell was working two jobs to pay the bills.

I'm not one to attribute every activity of man to the changes in the climate.

It is unlikely that Congress will ever pass that bill.

Remember when we thought our solar system might be unique in the universe? When we had no evidence--other than maybe a gut feeling, a hunch--that there were other planets beyond our solar family? It wasn't so long ago. It was 1992 when astronomers discovered the first extrasolar planets, around a dead star called a pulsar. The first planet around a "living" star was discovered just three years later.

We've come far, fast. Though we often emphasize that science advances incrementally and not in great "Eureka!" leaps, going from zero exoplanets to more than 500 in less than two decades feels pretty, well, leapy. In the months and years to come, that number is going to keep leaping ahead thanks in large part to the Kepler space telescope, which is busy staring at stars and searching for telltale brightness dips that might indicate the presence of eclipsing planets. In fact, if you watched NOVA's Hunting the Edge of Space when it premiered less than a year ago, you heard this:

Kepler has already discovered several new exoplanets. It hasn't found an Earth-like planet yet, but astronomers believe it is only a matter of time.

A matter of time, sure--but not much time. Earlier this month, scientists announced that Kepler had spotted 1,235 planet candidates ("candidates" because most still must be confirmed using a second detection technique), including 68 candidates that are about the same size as Earth. Of those 68, five orbit in the "habitable zone," where the temperature could be right to support liquid water.

How Kepler's planetary candidates break down by size. Image courtesy NASA/Kepler Mission/Wendy Stenzel.

At one of this morning's AAAS sessions, astronomer Sara Seager of MIT took us on an illustrated tour of some of these newly-discovered planets. There's Kepler-10b, "the first unquestionably rocky planet orbiting a star outside our solar system," which orbits so close to its star (more than 20 times closer than Mercury orbits the Sun) that lava oceans and rivers spill over its surface. This NASA animation captures an artist's conception of what it might be like to fly over Kepler-10b.

Then there's Kepler-7b, with the highest albedo of any known exoplanet. Albedo is a measure of reflectivity (you could say that Kepler-7b is the shiniest exoplanet), and this suggests that the planet is probably enveloped by highly-reflective clouds. Things get stranger still in the Kepler-11 system, where six confirmed planets orbit so tightly that they would all fit within Venus' orbit; five of the six orbit closer than Mercury. And in the yet-to-be confirmed system KOI-730, two planets share the same orbit like sprinters on a single lane of a track.

Kepler is turning up a "bonanza" of planets, as Harvard astronomer Matthew Holman put it, a weird and wild menagerie that is challenging our models of how planets form and bringing us ever closer to discovering a truly Earth-like world. So, if you catch a rebroadcast of Hunting the Edge of Space, in this small way it will already be out of date. We just can't keep up. And though it's part of my job as a researcher to make sure that our shows are up-to-the-minute, in this case, I think being out-of-date is something to celebrate.

There are 100 trillion microbes living inside of you. That's ten times the number of human cells in your body. And together, those microbes have more than three million genes--150 times the number of "human" genes in your body. If you assembled a genetic senate, your own DNA would have to fight for a single seat. Maybe we aren't quite as human as we thought.

I'm in Washington, DC, scouting for future stories for NOVA at the annual meeting of the American Association for the Advancement of Science. (That's a mouthful, so I'll just say AAAS from here on out). The AAAS brings scientists, policymakers, and journalists together for a long weekend of talks, public events, lots and lots of coffee, and--as I learned in one set of talks this morning--lots and lots of microbes. The AAAS attracts about 8,000 human attendees, so that makes eight hundred thousand trillion (80 quadrillion!?) microbes attendees.

But the human microbiome is under attack. Antibiotics, supplements, fad diets, fatty "Western" food, and behaviors and environmental factors we probably don't yet understand all put stress on the microbes that live in the human body. Scientists like David Relman (Stanford University) are trying to find out exactly what we're doing to our local microbes, and how quickly and robustly they bounce back from wallops like antibiotics.

Meanwhile, other researchers hope to develop new drugs that target microbiota instead of human cells. As Jeremy Nicholson of Imperial College London puts it: "Drug the bugs!"

Part 1: Cobra Face-Off
Part 2: Box Jellies
Part 3: Super Spiders
Part 4: Dinosaur Venom
Part 5: Platypus Tales

In anticipation of the NOVA/National Geographic special Venom: Nature's Killer, premiering February 23 at 9pm on most PBS stations, Inside NOVA is bringing you The Venom Chronicles, a five-part blog series exploring fascinating venomous animals and the researchers who study them. We are very much looking forward to giving you the heebie-jeebies, the creepy-crawlies, and a sense of awe at what these amazing animals can do. But before we get started, let's take a moment to talk about some venom basics.

Image Courtesy H Berends

What's the difference between venomous and poisonous animals?
Venom and poison are both substances that do harm, grouped under the umbrella term "toxin." The difference between them has to do with the delivery system. Poison must be eaten in order to be effective, as in the case of poisonous toads that injure or kill whatever tries to eat them. Venomous animals, on the other hand, usually have fangs or another related way of delivering the venom to their prey without needing to be eaten first. Of course, sometimes the two categories overlap. The yellow-bellied sea snake is a venomous animal with fangs that can cause serious damage if it bites you, but eating the venom can also be dangerous.

How does venom work?
Venom is made up of a combination of many different protein molecules that change the way your cells behave. The huge variety of toxins lead to many different effects on your body, depending on what kind of cells they target. An animal's venom may have one, some, or all of the following categories of toxins:
 

Neurotoxins affect the cells in your brain and nervous system. The most common effect is paralysis, but these molecules can also affect the way your brain cells communicate with each other.

Hemotoxins mostly target cells in your bloodstream, though they have impacts on other tissues as well. They can kill red blood cells, which deliver oxygen to the rest of your body, as well as disrupt normal blood clotting and cause organ failure.

Cytotoxins are responsible for spontaneous cell death in which a cell explodes and releases its fluid into the body. The tissue swells up and causes extraordinary pain.

The victory by IBM's Watson over all-time champions Ken Jennings and Brad Rutter that viewers of Jeopardy! saw this week is a milestone for those of us in the field of computer science known as Question Answering, or QA. It's not that we didn't see this coming; as a consultant for IBM's DeepQA team, I've seen Watson beat too many qualified opponents in evaluation rounds to be surprised by this outcome. But Watson is the first system with enough speed, accuracy and confidence to compete with humans at a real-time QA task like Jeopardy!.

Watson in training. Image courtesy of IBM.

The drama of this "man vs. machine" match gives our field a higher public profile and a jolt of credibility that will help us to promote a more effective way of interacting with computers using natural language.

Question Answering isn't a new line of research. The idea of asking a question of a computer in English and receiving a precise answer is something that people, and science fiction writers in particular, have thought about since the dawn of the computer age. One of the earliest QA systems, LUNAR, was built by Bill Woods and his team at Bolt, Beranek and Newman in the 1970's to help scientists retrieve data about Moon rocks. More recently, the explosion of the Internet and on-line information has led to great advances in document retrieval, and search engines like Google have become our default means of access to on-line text.

The big difference between a QA system like Watson and a search engine like Google is that Watson can read the text for you and provide a precise answer. Google will just give you a list of documents it thinks might contain the answer; you have to do the reading and answer-spotting yourself.

It's easy to see why question answering is a more effective way for humans to retrieve specific pieces of information. But until Watson came along, QA systems were typically too slow, too limited to a specific area of knowledge, or too inaccurate to perform well on an unrestricted, real-time QA task like Jeopardy!.

The NOVA episode Smartest Machine on Earth chronicles the four-year-long effort of a team of computer scientists at IBM to build a machine named Watson (after IBM's founder) that can play Jeopardy! -- a TV quiz show that represents for many the essence of human intelligence.

Working on this episode has caused me to reflect on a time many years ago when I made a NOVA called "Mind Machines." That film, like this new NOVA, is a reflection on the quest to create machines that can think like we do - in other words, artificial intelligence. In those days, that quest was just beginning and the results were pretty primitive. My film demonstrated a machine that could understand natural language well enough to manipulate different colored objects in a small world of blocks. It showed Eliza, a computer program that could respond like a psychiatrist, but was really just filling in the blanks based on what a "patient" had just typed in. The film began with a clip from Stanley Kubrick's classic "2001: A Space Odyssey," with its unforgettable scenes of the engaging but psychotic computer HAL running amok.

Artificial Intelligence, or AI, back then inspired two kinds of reactions: faith that it could be done and fear that it would. Most of the computer scientists I consulted were among the faithful. One accused me of being a "human chauvinist pig" when I expressed doubts. On the other hand, a few experts and most ordinary people worried that smart computers, like HAL, would get out of control and start running the world. What would happen to human values, these people asked, if silicon brains were more powerful than our own?

A lot has changed since then. First, a little thing called the Internet has come roaring into our lives. Unlike anyone I knew at the time, all the experts at MIT, Stanford and Carnegie Mellon that I interviewed had computers on their desks and could communicate with each other through cyberspace on a system called the ARPANET. A few years later, it's not just the experts who are benefiting from these innovations. Computers have become relatively cheap and accessible. Many of us have not one but several of them. We can communicate with each other across time and space and have a world of virtually limitless information at our fingertips.

And that's why, I believe, the fear factor has declined. We're used to computers. We know how dumb they are. We understand that they are limited to a narrow range of tasks we program them to do. The versatility of small children - the way they pick up language, navigate around obstacles, and learn to play games - is still out of reach for machines. And that's why, when we watch a computer named Watson compete against Jeopardy! champions, our admiration is less for its silicon brain than for the human ones that labored so long and hard to create it.

Publicist's note: Smartest Machine on Earth will premiere Wednesday, February 9 at 10pm on most PBS stations. Please check your local listings to confirm when it will air near you.