Did you know that scientists have found a 35-foot-long whale in a rock quarry in eastern Virginia? It’s true! In fact, it’s no ordinary whale — it’s a whale of a new species!
This whale’s no landlubber. It’s actually the fossil of a whale that lived 14 million years ago when eastern Virginia was covered by a sea. The whale was found more than a decade ago by dino-bone hunters (paleontologists) from the Virginia Museum of Natural History, but they didn’t identify it as a new species until recently.
Museum bone digger Alton Dooley says the whale is older by at least 3 million years than those related to today’s giant blue and fin whales. It was also several feet longer than any other whale in its time. Larry Barnes (Los Angeles County Museum of Natural History), an expert in fossilized marine mammals, agrees. This "almost modern-looking whale" lived considerably further back in time than scientists realized.
Now we go from the big to the small. We’re talking about chipmunks. Yes, a new study has found that, though chipmunks may be small, some were pretty hardy. In fact, new research has revealed that a group of them — living several thousand years ago in Illinois and Wisconsin — toughed it out through the last Ice Age rather than migrating south.
That’s the conclusion of Kevin C. Rowe, (University of Illinois) after performing some extensive DNA research on 244 chipmunks. The mitochondrial DNA, which is inherited from the mother, indicated that the animals came from 95 groups — and that 78 of those groups descended from ancestors who lived in the north and west. during the last Ice Age. Scientific theory has held that most animals would have fled south to escape the encroaching glaciers.
How did these tough little critters survive? Rowe says they lived in pockets of tundra and forest that the ice bypassed, leaving potential homes for animals. They would have had to survive there for perhaps 5,000 years, Rowe said. Now that’s a cold spell! Obviously they were good at gathering nuts.
A new study of Archaeopteryx — the most famous bird fossil first discovered 140 years ago — reveals that the first birds were probably four-winged gliders. These creatures only later evolved into the sophisticated flapping fliers with light skeletons and two wings that we see today.
That’s the latest thinking, anyway. As reported in New Scientist magazine, zoologist Per Christiansen of the University of Copenhagen, Denmark, and dinosaur digger Niels Bonde of Copenhagen’s Geological Institute, say that Archaeopteryx had surprisingly modern-looking feathers clustered along its back, around the legs and possibly on the base of its neck. In fact, these feathers are similar to plumage seen on birds today.
But here’s the twist. Christiansen says the leg feathers measure just 3.5 centimeters long, which makes them too small to have been used in flight. These feathers could be the remnants of a hind wing that the Archaeopteryx’s ancestors used. In other words, the earliest birds could have had four-wings, that they used for gliding, not flying. These feathers, the researchers believe, most likely launched the evolution of flight.
This month you might want to buy some ear plugs. From late May through June, we will be invaded by an army of cicadas. After spending 17-years in the ground, billions of cicadas will dig their way out and molt into adults. Once out, they will sing a raucous, gnawing, and LOUD love song. What we will hear is a sound akin to a billion two-cycle chainsaw engines trying to get started.
But nature is fickle. After seeing the light for the first time in 17 years, they will immediately become a brief feast for birds, and, according to Scientific American magazine, "an incomparable opportunity for researchers." Fascinated naturalists have been writing about periodical cicadas for four centuries. William Bradford, governor of the Plymouth Colony, first described periodical cicadas in 1633, although Native Americans probably knew of the creatures before then. The 17-year life cycle was firmly established less than a century later.
This month’s cicada invasion will be perhaps the largest and best studied.
What do we know about them? Well, they first emerge somewhere east of the Great Plains almost every spring. And while some 3,000 species of cicada are known worldwide, the life cycle for only a dozen of them are known. Scientists this month will be focusing their attention on what triggers their synchronized appearances.
"CSI: Crime Scene Insects," a new exhibit making a world tour (booked through 2007), explores the rapidly growing field of forensic entomology — in other words, how maggots and insects found at a crime scene can provide investigators with clues and help bring murderers to justice (see the January 2004 "Crime Scene Science" issue of ODYSSEY).
"It’s really kind of exciting," says Lee Goff, the exhibits curator and chairman of the forensic sciences program at Chaminade University in Honolulu, HI. "It’s a chance to bring something to people that 20 years ago I don’t think anyone would have been interested in."
Here’s the buzz. The types of insects on a body and their stages of development can help determine the time elapsed since the death occurred. They can also provide clues to the cause of death, where the victim was killed, and whether drugs or other toxins might have been involved. For example, in Hawaii, blowflies will start laying eggs on a corpse within 10 minutes of death. The eggs, in turn, hatch into maggots, which morph into pupae, which emerge from their shells as adult flies. Other insects show up later, Goff says — some to nibble on the corpse, some to prey on the other bugs, some to do both.
Insects’ development is so predictable and their behaviors so reliable that courts allow them as evidence. "They’re predictable and they really don’t care," Goff says. "And as long as you do a nice objective analysis of what’s going on, and you kind of follow their trail of evidence, they’re going to bring you to the truth about what happened."
The interactive exhibit gives visitors of all ages and interest levels the chance to sort through insect evidence at simulated crime scenes, and then try to solve the cases "It’s a little graphic, but they see worse stuff on prime-time TV," Goff says.
The exhibition made its world debut at the Science Museum of Minnesota on October 25, 2003. By May 2004, the Science Museum of Western Virginia in Roanoke, VA, will be its host. After that, the Smithsonian Institution’s Museum of Natural History in Washington, DC, will host the exhibit in Spring 2005.
One of the lingering mysteries of the insect world — how insects (such as water striders) seemingly skate across the surface of ponds, rivers, and oceans — has come to an end. The secret is out. John Bush, a mathematician at the Massachusetts Institute of Technology in Cambridge, MA, and his colleagues know the answer.
Water striders come in hundreds of different species. All can walk on, or skim across, water. They range in size from half an inch (one centimeter) long to 20 times bigger than that. For years, researchers believed that these watery lightweights move about by creating tiny waves. The thinking was that the insect could push backward against the face of a wave and move forward.
(Courtesy John Bush (MIT))
Lots of animals push. Humans push their feet against the ground. Birds push against the air. But the truth about the water strider isn’t that simple.
Bush and his research team used sophisticated tracking and a high-speed video camera to uncover the truth. The real secret to the bug’s motion, Bush says, is in its three sets of hairy legs. The water strider propels itself by using the hairs of its central pair of legs like oars. This action, like the oars of a rowboat, creates rearward swirling vortices that propel the insect forward at speeds of up to 60 inches (about 1.5 meters) per second. The vortices, by the way, are not spirals, but instead are an unusual "U" shape. Although tiny waves are created in the spirals, they are not the main driving force, Bush says.
To further prove their results, the Bush team created a mechanical water strider, called "Robostrider," based on the real thing. The robot — a soda can with stainless steel wire legs — has an elastic band and pulley at its middle (driving) legs. The results were the same.
In 1870, French novelist Jules Verne published his now famous 20,000 Leagues Under the Sea. The book follows the fictitious adventures of Captain Nemo aboard his submarine, the Nautilus, which is attacked by a giant octopus some 40 feet (12 meters) to 60 feet (18 meters) in length. Of course, everyone knows that such creatures are just the stuff of legends, right? Well, now it’s possible that one such "beast" has washed up on shore, for real!
On June 29, 2003, a 13-ton, 40-foot-long, bloblike carcass was discovered on a beach in Los Muermos, some 680 miles (1,100 km) south of Santiago, Chile, along the country’s southern coast. "Based on the preliminary data," says Elsa Cabrera, director of the Center for Cetacean Conservation in Santiago, "we think that it could be a gigantic octopus."
If it is, the fabled Octopus giganteus, a massive species of octopus — like the one in Verne’s story — lives! (That is, if there are more out there.) Cabrera contacted some other scientists around the world, and they all agree, she says, that the initial findings point to an octopus. Just to be sure, though, a sample of the "blob" is being sent to specialists in France for further study.
Upon hearing the news, not all scientists are convinced. "It’s whale blubber," says Roland Anderson, an octopus expert at the Seattle Aquarium in Washington state, "or maybe a basking shark." These Octopus giganteus alerts, Anderson says, happen every so often, and go back hundreds of years. The "blobs," however, have always turned out to be either whale blubber or the decayed portion of some other large sea creature. Besides, Anderson says, a 13-ton octopus would have to be a lot bigger than 40 feet long. "Octopuses just don’t get that big," he said.
We’ll see. . .soon enough.
The next time a black cat crosses your path, don’t panic. Instead, think about the recent research by Stephen O’Brien and Eduardo Eizirik, evolutionary geneticists at the U.S. National Cancer Institute in Maryland. If the researchers are right, dark fur has a survival benefit.
Here’s the scoop. The research began with a simple question: What makes a cat black? The scientists weren’t passing time. They had a gut feeling that the genes involved in making a cat’s coat turn black may also protect the animal against disease.
Well, O’Brien’s team did find the gene (called MC1R) that, when mutated, makes a cat’s coat turn black. In fact, O’Brien and his team said that they found that the black domestic cat, the jaguar, and the small South American jaguarundi each derive their black coloring from a different type of gene mutation.
MC1R is in a family of genes called 7-transmembrane receptors. A receptor acts as a doorway into cells and is often used by bacteria and viruses to infect cells. The HIV virus, for instance, enters cells through a 7-transmembrane receptor. So, the genes that give a cat its black coat are in the same gene family as those involved in acquiring human diseases like AIDS. Black cats with the mutated gene may be more resistant to disease than cats of other colors. Learning more about this gene might help in human disease research.
The discovery casts a new light on animals that at one point were even tortured by people who saw them as agents of the devil. "We have had black cats and they have been mythical all along," O’Brien says, "but now they have been demystified."
Only a few species of animals are known to have "true navigation" –- meaning that they can find their way home even if transported to a totally different and unfamiliar environment. Most vertebrates are thought to be true navigators, but vertebrates make up only about one percent of all known living species. To date, only one species of "spineless" wonders (invertebrates) have been shown to be capable of true navigation, the Caribbean spiny lobster, Panulirus argus.
For most of the year, spiny lobsters spend daylight hours inside coral reef crevices, emerging at night to feed over considerable areas before returning in nearly total darkness to the same den. Spiny lobsters also show a remarkable ability to keep a constant course while migrating under water and to find their way even in darkness. Now researchers have discovered that they can also return to their feeding grounds after being displaced by some 12 to 37 kilometers.
(Courtesy Ken Lohmann)
How do the lobsters navigate so well?
To test a theory that spiny lobsters have a well-developed magnetic map sense, Larry Boles and Kenneth Lohmann (Department of Biology, University of North Carolina, Chapel Hill) captured lobsters, which they then relocated — some to the north of the capture site and some to the south. The result?
The lobsters relocated north of the capture site immediately oriented themselves southward, whereas those relocated south of the capture site oriented themselves northward. When instead of transporting the lobsters, the investigators simulated the values of the magnetic field that would be encountered at northern and southern sites, the lobsters showed the same responses. So true navigation in spiny lobsters, and perhaps in other animals, is based on a remarkable "magnetic map sense" similar to that found in newts and thought to play a role in the long-distance movements of other vertebrates such as sea turtles and migratory birds.
It’s true. Just ask San Francisco Zoo’s penguin keeper, Jane Tollini. She witnessed firsthand one of the most bizarre migrations on record — dozens of Magellanic penguins attempting a 3,200-kilometer migration in the zoo’s swimming pool.
Magellanic penguins in the wild normally migrate each year along the coast of South America from Argentina to Patagonia. The trip takes about six months. The pool saga began in November 2002, when six of the penguins, formerly of Sea World in Aurora, Ohio, were brought to the San Francisco Zoo and penned with that zoo’s 46 penguins. Suddenly, all 52 penned penguins at the zoo began doing something they hadn’t done before — daily circular laps in unison. Tollini says that the penguins would start swimming in circles early in the day and would rarely stop until they staggered out of the pool at dusk. "I can’t figure out how the Aurora penguins communicated and changed the minds of the other 46," Tollini says. But they did, and the penguins kept lap-swimming until they had completed the "migration" — 26,400 pool laps. (Penguins can swim up to 24 kph.)
But Christina Slager, associate curator at California’s Monterey Bay Aquarium, has studied Magellanic penguins in the wild in Patagonia and Chile, and she is not surprised. Penguins, it turns out, are not only extraordinarily social animals but "very, very inquisitive," Slager says. Of course, you need to be more than inquisitive to join in such a feat. Indeed, aquatic biologist Pam Schaller (Steinhart Aquarium, San Francisco) says that penguins are not only social but also genetically designed to swim. "I’d be more amazed," Schaller says, "if the six had learned to do something not in penguin nature and showed the other 46 how to do it — like if the birds were trained to jump through a hoop."
When you hear the word "salmon," what comes to mind? If you’re like most people, you’ll say "a pink fish jumping up a stream." Or maybe "a fresh fillet." But ask Brian Kennedy that question, and he’ll probably reply, "Ear stones."
Kennedy’s not strange. While studying Atlantic salmon ears, the researcher in geological sciences at the University of Michigan found a naturally occurring chemical signature (from a type of strontium — a soft metallic element) in bony tissues, known as ear stones, in the salmon. What’s exciting about this discovery is that this chemical signature could help biologists track the seasonal movements of the endangered fish.
Salmon spend most of their life at sea, but return to their native river to lay eggs. Migrating fish move into their home streams in early summer and then swim upstream when conditions are right to spawn in late autumn. To follow the migrations now, scientists can monitor the strontium levels in the stream. If they see a significant change, they’ll know that the salmon have arrived.
New findings about endangered basking sharks, the United Kingdom’s largest fish, have scientists harpooning a 50-year-old myth, stopping it dead. Basking sharks span 10 meters in length and weigh several tons. The solitary animals feed on plankton and are harmless to humans. They have been hunted to near extinction for their liver oil and fins. For the last half-century, biologists had assumed that the docile sharks populate the same waters year-round, diving deep only when it comes time to hibernate.
But it looks as if scientists definitely were wrong. As British biologist David Sims (Marine Biological Association) told a reporter for New Scientist magazine, basking sharks do not descend to deep waters and sit on the sea bed to hibernate as previously thought. "They are very active creatures," Sims said.
The discovery came after Sims had spearheaded a study that tagged 20 of the huge sharks — so that their movements could be monitored by satellite. The study revealed that the sharks explored vast tracts of ocean in search of plankton, traveling thousands of kilometers in a month or two.
Although the sharks are an endangered species in the United Kingdom, Sims found that they spend 99 percent of their time outside the area of British protection — 19 kilometers off the coast. Sims recommends that the United Kingdom extend its protected areas, pointing out that in the United States, basking sharks are protected out to 480 kilometers from the East Coast.
Ever wonder how an African dung beetle navigates?
Well that’s okay. After all, dung beetles have some pretty disgusting habits, like rolling excrement into little balls and consuming them. So who would have thought that this little creature would possess a hidden talent?
Marie Dacke (University of Lund in Sweden) and her colleagues, that’s who. These "dung-hard" scientists discovered that their little beetle navigates by moonlight. It turns out that competition among dung beetles for food is fierce and there are many aggressors. So it behooves the beetle to roll and run. And the fastest way to flee is in a straight line. Curiously, the dung beetles only flee in a straight line when the Moon is out. On cloudy evenings, or when the Moon is absent from the sky, the beetle moves erratically. An amazing feat, since moonlight is one millionth as bright as sunlight.
To prove the theory, the researchers placed a polarizing filter over ball-rolling beetles. Polarized light is perpendicular to the direction of a light ray. So it should alter the Beetle’s course by 90 degrees. And that is just what happened. Under the filter, the creatures made right-angled turns, suggesting they orient themselves according to the polarization of the Moon’s light. "This ability," Dacke says "may turn out to be widespread in the animal kingdom."
That’s one question that’s not on many minds, but, of course, scientists are curious folks, so they endeavor to learn such things. Here’s what’s so intriguing: bugs don’t have lungs. So how do they breathe?
Well, it took one of the world’s strongest X-rays — one many hundreds of times more detailed than those you get at the hospital — for scientists at The Field Museum in Chicago and Argonne National Laboratory to learn. Using these intense X-rays, the researchers videotaped how beetles, cricket, and ants breathe.
How do they breathe? By forcing air in and out of tiny oxygen pipes. "They are really pumping some gas," said museum zoologist and lead researcher Mark Westneaty. While resting, the insects exchanged up to half the air inside their main oxygen tubes every second. That’s about how hard a person breathes while doing moderate exercise.
The X-rays created a window into these tiny little animals that nobody’s ever seen inside before. The tiny oxygen tubes (called tracheae) connect to tiny air holes in the insect’s outer coating. For decades, scientists thought air just happened into those holes. But the X-rays also revealed some tiny air sacs near insects’ wings, legs, and abdomens, which might be used to help pump air inside. So these pumps could behave like our lungs, sucking air in and out of the insects’ bodies.
"It’s an important discovery," said insect researcher Robert Dudley of the University of California, Berkeley — and equally important is the technology that allowed it.
Well, enough about killer math. How about killer aliens! They’re big, they’re bad, they’re killing shrimp. Alien jellyfish have arrived in the Gulf of Mexico, and they’re threatening to hurt the local shrimp industry. They’re aliens, not because they come from Mars, but because they come from Australia (you get the picture!). So far, the giant jellies have been spotted only in the northern part of the Gulf. But that doesn’t mean they can’t invade elsewhere.
What’s really fantastic is that these transparent blobs – of the spotted variety Phyllorhiza punctata – usually measure only 15 to 19 centimeters in length. But after feeding in the algae-rich waters of the Mississippi Sound, they’ve achieved diameters of 40 centimeters!
How are they threatening the local shrimp industry? Well, no one knows for sure, but scientists like Monty Graham of the Mississippi-Alabama Sea Grant Consortium, a group made up of eight local universities and research facilities, suspects that if the monsters survive the winter, they’ll turn their attention from algae to shrimp eggs and larvae. If they do, their effect on the Gulf’s environment and commercial fisheries could be one of the area’s biggest problems next year.
Humans and other modern mammals may be big and brainy, but we have to thank our tiny ancestors for our current success.
That’s right. Way back in the Age of Dinosaurs, (some 195 million years ago) our mammalian ancestors were scurrying shrew-like critters. But not all these shrews were alike. You see, the tiniest of these shrews — the mini-shrew Hadrocodium — had jaw and skull features more closely related to the modern mammals than any of its larger contemporaries.
The skull of one of these tiny critters was recently found in China. The 0.5-inch (13 millimeter)-long skull was one-half to one-third as long as the skulls of any other relatives of mammals living at the same time. It is the smallest mammal discovered from the age of the dinosaurs! Hadrocodium weighed just two grams and ate small insects and worms. Palaeontologist (dinosaur digger) Alfred Crompton of Harvard University said this tiny jaw and skull structure led to it having exceptional hearing. And their keen ears allowed many of them to survive those dark nights teeming with big predators.
Today, the smallest living mammals are the bumblebee bat and the least shrew.
Here’s looking at you, kid. Did you know that birds can sleep with one eye open? Weird, huh? Birds have the uncanny ability to make one hemisphere of their brain stay awake while letting the other hemisphere fall asleep. The eye connected to the alert half of the brain stays open, while the one connected to the snoozing half closes.
Some recent duck research at Indiana State University has now determined that this bird-brain behavior helps birds survive in the wild. No one has to tell you how "quacky" a night can be for a bird sleeping on a lake. While "sleeping" in water, a duck (or swan, or any other water bird) will keep half of its brain awake to keep one flipper paddling (so it won’t drown), and keep one eye open for predators (so it won’t be killed). The question is, do other animals do it? If not, why not?
The answer seems to be that many animals probably lost the ability to control their drowsy brains a long time ago, because they spent much of their day sleeping safely in burrows or caves, protected from the creepy crawly things that go "Yum!" in the night. Yet, some modern lizards will occasionally sleep with one eye open, especially if they have recently seen a predator. The Indiana researchers believe that this "eye-opening" behavior may have been handed down genetically by some ancestral lizard that lived more dangerously in the open. On the more subtle side, studies of human brain-wave patterns reveal our ability to be "bird-brained," especially after a person has experienced a severe trauma. A very old part of their brain is probably telling traumatized people to keep an "eye open" for danger.
Concern about frog deformities dates to the early 1990s, when schoolchildren and amateur naturalists first began finding frogs with deformed legs in U.S. wetlands. Ever since, scientists have been trying to determine the cause (see ODYSSEY, May 2002).
Until now, there have been two leading theories: One focuses on chemicals, such as pesticides, that contaminate the frogs’ environment, and the other points a finger at a disease-ridden parasite, the trematode worm. Scientists had found evidence to support each hypothesis.
Enter biologist Joseph Kiesecker (Pennsylvania State University) and his colleagues, who have now conducted the first experimental study of frog deformities in a natural habitat. Kiesecker and his team collected tadpoles from ponds in Centre County, PA. They used some of them in a series of laboratory experiments, and the rest in a series of field experiments conducted in six ponds within the same region.
What Kiesecker discovered was that deformities in Pennsylvania wood frogs are indeed the result of parasites causing infectious cysts. In fact, it appears that tadpoles have to be exposed to trematode infection for limb deformities to develop. But the experiments also showed that these deformities occurred with more frequency in the groups of tadpoles that also were exposed to pesticides.
In other words, pesticides can weaken a tadpole’s immune system, making it more susceptible to trematode infection and cysts that are likely to cause limb deformities. "It is not uncommon now for 20 to 30 percent of the frogs at many locations to have limb deformities," Kiesecker says.
Not that we didn’t already know it, but bottlenose dolphins are intelligent . . . very intelligent. Now researchers at the New York Aquarium in Brooklyn can prove it. Hold up your cat or dog to a mirror and they won’t tilt their heads in wonder at themselves. But two dolphins (13-year-old Presley and 17-year-old Tab) swimming in a pool with mirrored walls did recognize their own reflections – a quality once shared by only humans and great apes (chimpanzees, gorillas, bonobos, and orangutans).
How do we know that’s what they were doing? Well, after Diana Reiss (Osborn Laboratories of Marine Science, located at the aquarium) and Lori Marino (Emory University in Atlanta, GA) marked the dolphins’ bodies with nontoxic black ink, Presley and Tab swam to the mirrored walls to check out what had just been written on their bodies. Whenever one dolphin saw the other with a marking, it couldn’t care less. But whenever a dolphin received a mark itself . . . whoosh! It quickly swam over to a mirror to assess its body.
In fact, the researchers said that the dolphins spent more time in front of the mirror after being marked than when they were not marked, and the first behavior when arriving at the mirror was locating the black mark to check it out.
"What we see," Reiss said, "is that [dolphins] have excellent skills for memory. They are able to learn and comprehend artificial codes." Unfortunately, dolphins are being slaughtered in some parts of the world. Reiss’s study should heighten our awareness of the need to protect these animals.
There’s a freakish fish out there, lurking in our freshwater streams and ponds, that’s causing our government quite a fright. Frankenfish, an Asian snakehead fish, is truly a monster. It has heavy scales and a wide, ugly mouth — with teeth sharp enough, and jaws powerful enough, to bite other fish as big as itself in half.
Frankenfish can measure up to a meter (3.3 feet) in length, walk across land, and stay out of water for up to three days. It’s a voracious feeder, and will consume fish, frogs, aquatic birds, and small mammals. It’s even been known to attack humans. The fish has such a ghastly reputation that the people of northern Thailand and Myanmar (formerly Burma) believe that sinners are reincarnated into snakehead fish.
(Florida Fish and Wildlife Conservation Commission)
Frankenfish were discovered in the United States last summer after someone dumped them into a Maryland pond. Since then, the fish have been found in six other states — Hawaii, Florida, California, Maine, Massachusetts, and Rhode Island. The government is planning to place a ban on importing 28 species of snakehead fish, unless a special permit is granted. The trouble is, if these Frankenfish get into larger water systems, they could alter the food chain and displace other species. Tests are now being performed to find the best way to eliminate the existing snakehead fish in our waters.
Why were these ugly fish brought into our country? To eat! Believe it or not, in Asia, the fish are considered a delicacy (a recipe for watercress soup with snakehead fish can be found at this Chinese food recipe Web site: www.foodno1.com). It seems, however, that whoever dumped the fish into our waters couldn’t stomach the thought of eating them! Could you?
Say you’re a lizard. (And don’t say, "You’re a lizard"!) If I’m your owner, how do I know you recognize me? Hmmm. If I couldn’t talk, and I recognized a familiar face that just walked into the room, I would probably nod my head. In fact, you probably do it yourself, like during class when someone you know walks in late and your eyes meet. Well, pat yourself on the back, because you now share a behavioral trait with an iguana named "Fido."
That’s right. Scott McRobert and his colleagues at Saint Joseph’s University in Philadelphia believe that their lab pet Fido can recognize McRobert (the lizard’s handler) from strangers. Amazingly, this discovery began as a joke. McRobert’s colleagues first noticed that Fido would bob his head whenever McRobert approached. But the "cold-hearted" lizard seemed to ignore everyone else. The researchers teased McRobert about his lizard’s behavior, until it dawned on them that Fido might really be acknowledging McRobert’s presence.
It was time to test the 12-year-old lizard. McRobert, together with a lab student who had cared for Fido for four years, and some 40 strangers took turns reading to Fido. They read out loud or silently, in front of Fido’s cage or behind a screen. Another researcher counted the iguana’s head bobs.
When Fido could see the readers but not hear them, he bobbed his head roughly equally to both the student and McRobert, but almost totally ignored the strangers. When they read aloud, however, Fido bobbed his head about three times as often to McRobert than to the student. So it appears that Fido can not only recognize McRobert’s face, but also his voice. Despite the seemingly amiable head bobbing, McRobert suspects Fido doesn’t love him. Instead, he believes Fido singles him out because iguanas are not used to being handled, so Fido probably sees McRobert as a threat, not as a friend.
By buying it a diamond ear ring? No. Kidding aside, this was a problem facing wildlife officers in South Africa’s Kruger National Park when they began the world’s largest elephant relocation program last October. The goal was to move 40 of the large animals from Kruger to an area just over the border in Mozambique.
Moving an elephant requires darting it first with an anesthetic. Once groggy, the elephants are moved into custom-made crates, revived with an antidote to the anesthetic, and then loaded onto trucks for the journey. The move is part of a larger plan to create a 21,600-square-kilometer wildlife park by April. The new park will encompass Kruger, a similar area in Mozambique, and Zimbabwe’s Gonarezhou Park.
One reason the elephants needed to be moved from Kruger is that the ever increasing population of 9,000 animals was becoming too large for the park to sustain. Rather than shooting 1,000 animals over the next five years (to diminish the population), the wildlife officers decided to repopulate an area in Mozambique that had lost most of its herds during the latest civil war.
Using relocation to manage elephant populations, rather than culling, is becoming increasingly popular, says Will Travers of the Born Free Foundation (based in the United Kingdom). Overall, elephant relocation programs have met with success. Ultimately, the plan is to relocate 1,000 elephants over three years. Still, Travers thinks that a better solution to habitat pressure in the long term is fertility control, not relocation. Elephant contraceptives are currently being tested in South Africa, Kenya, India, and Thailand.
Like a good puzzle? Try this one. When Dolly, the famous cloned sheep, has a birthday, how many candles should be on the cake? The obvious answer is as many candles as the sheep is old, right? Dolly is now three (as of November, 1999), so the cake should have three candles. But a new study suggests that Dolly’s genetic material is aging at the rate of the 6-year-old sheep from which she was cloned. So, though Dolly has been on Earth only three years, her genetic makeup says the sheep is twice that old.
Don’t worry, Dolly’s still eating daisies, not pushing them up. Sheep normally live about 13 years. So we’ll see in a few years how Dolly is doing. Right now, she looks healthy and is acting normally, but geneticists say there’s a greater risk now that she’ll contract cancer, which occurs when cells fail to self-destruct and begin uncontrolled growth, usually as we grow older.
Right now, there is no clear indication that cloning is unsafe, but warning signs are beginning to flash in scientists’ minds. Of course, if Dolly does prematurely age, the development will raise new ethical and medical concerns about cloning. For instance, is it safe to use cloned cells to help fight diseases, since the cloned cells may be susceptible to premature aging and disease?
The next time you look at your cat, perhaps when it’s sleeping or rubbing against your leg, purring, think of this: That kitty’s dim and distant ancestors were probably stalking and killing humans 2.5 million years ago.
That’s right. According to the magazine National Geographic, South African archaeologist Julia Lee-Thorp (University of Cape Town) and her colleagues discovered the fossils of several "kitty" predators that once preyed upon humans in South Africa. These beasts included Megantereon, an extinct saber-toothed cat with oversize fangs, as well as leopards and giant hyenas. The team’s findings are based on a study of the chemical composition of the tooth enamel of these prehistoric carnivores. Tooth enamel is composed mostly of calcium and phosphate, but also includes small amounts of carbon, the concentrations of which can tell researchers a lot about the cats’ diets. In this case, the diet was high in human flesh.
Believe it or not, researchers long have suspected that leopards and spotted hyenas have chomped on humans. Even today, the modern descendants of these flesh-eating mammals have been known to attack and devour humans. And though Lee-Thorp says that there is not enough evidence yet to absolutely convict any of these predators, she is looking forward to collecting more evidence at other dig sites.
You’ve all seen it on TV – a cheetah running and running and chasing and chasing some helpless vegetarian across grasslands. Well, according to Japanese ecologist Shigeo Yachi (Kyoto University in Otsu), all predators hunt using math – from jumping spiders to darting fish-scale eaters.
You see, a creature has to know what, when, and how to attack. And Yachi believes it all comes down to one simple equation – the animal simply must weigh the merits of getting closer to the prey against losing the element of surprise. His mathematical model shows that when the risk of being noticed by prey outweighs the advantage of proximity, the predator pounces. Take the following example: Yachi says that jumping spiders will attack an adult house fly from afar, presumably to maintain the element of surprise. But they get a lot closer before attacking a house fly maggot, which is less likely to flee. Using camouflage, the spiders can get closer to their prey before attacking.
One element of the hunt that doesn’t factor into the equation, says Yachi, is the time it takes to stalk a prey. What’s critical, he says, is the decision to attack or hold off. That’s where the "calculating" comes in. Here’s another gross example: scale eaters. According to Yachi, his mathematical model fits perfectly with predatory fish that dart in to snatch the scales of other live fish. The scale eaters are smaller than their prey, and if noticed they escape rather than attack, a behavior that the model again predicts.
Now, despite what was said earlier about Yachi’s model applying to all predators, there are a few exceptions to the rule. "The model cannot be applied to coursing predators – meaning they move swiftly over a course – such as wild dogs, wolves, and hyenas," Yachi says, "because their hunt does not rely on the merit of surprise."
I suppose what every math teacher is now wondering is . . . can a cheetah cheat?
Seen any lice lately? Well you can if you use a new "illuminating" shampoo developed in the United States. The new shampoo causes lice eggs to glow under ultraviolet light, making them much easier to spot and remove by hand. By the way, did you know lice are also called "nits" – thus the phrase "nit picking."
Anyway, about 14 million children get head lice each year in the United States. Shampoos currently in use are becoming less effective at lice removal, because the lice have become resistant to the pesticides in these shampoos (Yuk). The pesticides were bad for children anyway. But thanks to Sydney Spiesel, a pediatrics professor at Yale University School of Medicine, we now have a special shampoo that uses an organic dye. The dye is "delightfully cheap and delightfully non-toxic," he says.
What’s more is that the eggs glow brightly when a "black" (UV) light is shined on them, which made it easy for parents to nit-pick their kids’ hair. So where is this shampoo? Not so fast. Spiesel has a patent on his lice-detecting shampoo, but he hasn’t licensed it. He says he’s looking for a business partner to help him bring it to market. Meanwhile, parents should routinely check their children for signs of head lice and use a nit comb to remove the tiny – less than a millimeter across – eggs.
Many of us have seen the movie, "Ghost in the Darkness," about a vicious pair of lions that fed on more than 130 railroad workers in Kenya in 1898. The really big cats (3 meters long) were hunted and killed, and their skins and skulls were later sold to the Field Museum of Natural History in Chicago.
Now Bruce Patterson, a Field Museum zoologist, finally got a moment to check out these infamous skulls. What can you do with a century-old skull? Well, you can take it to the "dentist" and X-ray its teeth. And when Patterson did this he found that one of the lions had a broken canine tooth with "a wicked abscess at the base." Canines are those long sharp pointed teeth that lions use to grab the throat of its prey. But "this cat would have been unable to put any pressure at all on this tooth," Patterson said, so "It went looking for something slower, softer and less capable of defending itself," – meaning humans. Although the other lion had a clean dental record Patterson thinks it could have been following the other more dominant male, you know "Lion see, Lion do."
Wow! Can you believe it? The first nonhuman primate – a monkey – has been cloned. It happened in January 2000, when researchers at the Oregon Regional Primate Research Center in Beaverton announced that they had created "Tetra," a female rhesus macaque.
They did it by splitting a very young embryo into four pieces. That’s a different method than what scientists used to create Dolly, the cloned sheep. Dolly was created by taking a nucleus out of an adult cell and placing it in an unfertilized egg. The new procedure proves that a divided embryo, if very young, can grow into a completely separate, identical adult organism.
Tetra is a "100 percent" clone. Dolly is not, because Dolly has genetic material from both an adult cell and from the egg that was used to make the clone. The new method used by the Oregon researchers, however, is not very efficient. The researchers made 368 embryos by splitting 107 embryos into two or four pieces. They got four pregnancies in 13 tries. Only Tetra survived.
The same method was used in 1993 to create clones of human embryos, though those embryos were destroyed. The researchers hope to create more genetically identical lab animals for use in testing. They have four other pregnant monkeys, which could start delivering this month.
Inquiring minds have been wondering: "Will Dolly, the cloned sheep, live a long and healthy life, or will she just live out the remaining days of the six-year-old ewe from which she was cloned?" A normal life for Dolly would be about 10 years, while a less-than-normal life would mean a life expectancy of about four years.
The problem with Dolly seems to be that the age-related structures at the tips of her chromosomes, called telomeres, appeared shorter than they should be for a young sheep. Well, there’s good news from the cloned cattle front – yup, they’re cloning cattle, too. It appears that Dolly’s shortened telomeres were a freak (pun intended) occurrence. You see, a herd of scientists, rounded by up Robert P. Lanza of Advanced Cell Technology in Worcester, Massachusetts, have shown that cloned cattle have longer than normal telomeres. Well, I guess that’s the long and short of it for now. I think time will be the true judge.
And on that farm he had some clones. Only, the "farm" is at Texas A&M University, about 130 kilometers northwest of Houston, TX, and "Old MacDonald" is really a group of scientists that has been cloning around with a menagerie of animals — namely, a couple of bulls, a goat, and a litter of five pigs. (The scientists are also struggling to produce a cloned dog.)
"In effect, this is the world’s first cloned animal fair," said Jorge Piedrahita of Texas A&M’s College of Veterinary Medicine.
But not all is well on the "farm." Although Piedrahita and his fellow "farmhands" (researchers) produced multiple animals from the same genes, each clone came out a little different. And though the animals on display looked healthy – they mooed, bleated, and oinked – the researchers admitted that the animals showed a high number of abnormalities.
"We still have a lot to learn about the process," Piedrahita said. "We don’t know what we’re doing to these animals."
One thing the researchers said they had learned was that it was far too early for anyone to think about cloning human beings, as some groups have proposed. So far, dogs have also proved impossible to clone. Their dog cloning project, called the "Missyplicity Project," began in 1998, when a wealthy California couple gave the school $2.2 million to clone their late, beloved collie, Missy. The school is also trying to clone cats, and the researchers expect that they’ll see one sometime this year.
"There are hidden depths to chickens." That’s the latest word from behavioral scientist Christine Nichol (University of Bristol in southern England). She and a clutch of other researchers recently reached that conclusion after years of studying chicken behavior.
But that’s not all. Nichol and her colleagues say that pigs, too, demonstrate "cunning behavior."
The lowdown, she says, is that pigs and chickens are more intelligent than most people believe. How smart is smart? Well, the research suggests that chickens can learn from each other and are encouraged by example — like children! Chickens have been taught what food to eat or avoid; the birds also can adapt their behavior and can learn to navigate.
Pigs are no "birdbrains," either. They can sense or "read" how knowledgeable a fellow pig is, and then use that information to take advantage of a situation — say, to obtain food. How’s that for being cunning? They can also assess the strengths and weaknesses of their rivals and then figure out which subtle behavioral signal will best demonstrate their strength over a rival’s. Fact is, the researchers say, pigs and birds can "develop quite sophisticated social competitive behavior, similar to that seen in some primate species."
A better understanding of such animal intelligence could help farmers sort out their own problems — such as how to minimize aggression in pigs, which causes deaths and injuries each year. So who’s learning from whom?
The scene is straight out of a horror movie: A creature has just been killed. The person who killed it leans over the body to make sure it is dead. Suddenly, the corpse leaps up and . . . well, you know the rest of the story.
Now scientists have discovered that reality can be scarier (and deadlier) than fiction. Frank LoVecchio and Jeffrey Suchard, doctors at the Good Samaritan Regional Medical Center in Phoenix, Arizona, warn that dead rattlesnakes can bite after death. What’s more, such supernatural strikes are surprisingly common. In fact, nearly 15 percent of the people LoVecchio and Suchard have treated for rattlesnake bites were attacked by freshly killed or mutilated animals.
Of the 34 rattler victims they treated, five claimed the snake had been "thoroughly dead" when it attacked. What does "thoroughly dead" mean? Well, one patient said he shot a rattler, chopped off its head, waited five minutes, then picked up the head. But the dead head lunged, stabbing its fangs into the man’s finger. When the man grasped his stricken finger, the head bit him on his other hand.
Don’t believe that one? Okay, another victim, who says he knew the dangers of posthumous rattlers, said he grasped a decapitated rattler’s head tightly with the fangs pointed away from him. But somehow the jaw shifted, scratching him. So much venom was injected into him that he had to have a finger amputated.
Really, it’s true! In fact, other studies have shown that an isolated rattlesnake head will try to attack objects waved in front of it for up to an hour after death. Joe Slowinski, a herpetologist at the California Academy of Sciences in San Francisco, says these day-of-the-living-dead episodes appear to be a reflex action, triggered by infrared sensors in the snake’s "pit organ," a structure between the nostril and eye that detects body heat. A decapitated snake’s body can also attack, Suchard says, since it has touch sensors that can cause the headless corpse to jump and whack an unsuspecting observer with its bloody stump. "A dead snake still has many of the reflexes it had when it was alive," he says.
So what do we do if we see a dead rattlesnake? Suchard advises us to leave it alone. "If you really have to touch it," he says, "I suggest you use a very long stick." He also says that many of the problems could be avoided if people didn’t try to kill them in the first place.
By the way, believe it or not, I was attacked by a dead pygmy rattler in the Florida Everglades. Fortunately, I touched the animal with a long stick.
Why didn’t the vole – that little short-tailed rodent of the genus Microtus – cross the road? That seems to be one of the big questions echoing through the halls of the University of Konstanz in Germany. You see, researchers there had a major revelation: Motor vehicles do more than just flatten skiddish animals. (You’re right, we really should spell it correctly as "skittish," but a pretty good pun, no?) Large highways, they say, act as effective genetic barriers for these critters, just like rivers and mountains. Huh?
Okay, here’s the scoop. It turns out that after an "exhaust"-ive study of vole populations near major highways, the researchers discovered that the voles living on one side of a four-lane highway were genetically different than those living on the other side. That means voles are having a hard time crossing the wide road, preventing them from mating. That also means that certain species of voles are heading toward extinction – thanks to the highway.
Is there a parallel problem here in the United States? Yes! According to researchers with the Savannah River Ecology Laboratory of the University of Georgia, roads also play a role in the worldwide decline in reptiles. Although the road-related drop in amphibians is well documented, reptiles may be suffering even more: According to World Conservation Union figures, 3.82 percent of the approximately 7,150 reptile species are extinct, endangered, or vulnerable, compared with 2.75 percent of 4,680 amphibian species. Human activities such as habitat destruction and commercial trading are the main problems.
It’s amazing. Who ever thought the day would come when scientists would start calling tadpoles – those wriggling, squiggling, pond-pips soon to become frogs – not just interesting, but "remarkably sensitive organisms" and "amazingly complex animals." But that’s the emerging message in the cover article of a recent issue of Science News.
In fact, scientists say jokingly that if the field of tadpole research continues at its current growth rate for another 15 years, every new scientific paper in the world would be about this once uninspiring animal.
So what’s the skinny? Well, some of this exciting new research is about . . . tadpole teeth! Yes, researcher Ronald Altig (Mississippi State University) is extremely passionate about tadpole incisors, arguing that we have not fully understood how tadpoles use them! (Hmmm.) Tadpole teeth sprout above and below the mouth in curved rows. "It’s as if you had hundreds of teeth on your upper lip and chin," Altig explains. The teeth are not calcified like those of adult frogs, but instead are made of keratin, the same material that makes up our hair and nails. The teeth are outside so that the animal can scrape and slurp up bacteria, fungi, algae, and other delectables from pond surfaces.
The mouth is also unique. It has an extra hinge on the lower jaw, which allows the mouth to open super wide. But wait. There’s more! The lower cavity of the mouth – which has a bunch of gummy cords – moves up and down in a pumping action. "Yummy" particles get trapped by the gummy cords and are swallowed before the water carrying them rushes over the gills and outside the body. It’s a most efficient system, Altig says, because the gummy trap can capture, in one pass, more than three quarters of the particles that enter the tad’s mouth. The fact is, tadpoles have many different mouth parts to capture particles in water. Altig believes that discovering the links between these mouth parts and the tadpole’s environment and feeding styles is one of the challenges facing future tadpole researchers — whose work, he hopes, will benefit us more than . . . er . . . just a tad.
If you thought that last scoop was exciting, wait until you read this one! Science News also reports that the most exciting finding to come out of recent tadpole research is the way tadpoles respond to danger. Yes, tadpoles have a reason for being so squeamish . . . You see, they are the preferred animal to eat – if the predator is the size of a dragonfly larva or larger. Talk about stress!
Indeed, ecologist Rick Relyea (Univ. of Missouri in Columbia) raised six species of tadpoles in a tub. A mesh cage in the same tub held a predator such as a dragonfly larva or water bug (how terrifying!). Earlier experiments had shown that tadpoles became immobilized or changed their body shapes when a predator was present – especially a predator that had been eating some of the tadpole’s friends. Relyea and his colleagues confirmed these findings, but added that the tadpoles could adjust either their behavior or body shape, depending on their assessment of the danger. Scientists once thought that tadpoles’ defense mechanisms became stronger as predators became more dangerous.
But it’s not that simple, Relyea discovered. Tadpoles have several options. For instance, it may behoove the tadpole to remain immobile most of the time to avoid attention, or it could instead grow a deeper tail fin to make quick escapes, or it could benefit from both defense mechanisms!
And predators aren’t the only problem. A pond overcrowded with tadpoles increases stress for the individual trying to find food. Usually, Relyea found that when a predator is present, tadpoles grow high-speed tailfins and remain relatively immobile. But when they are in a crowd of other tadpoles, the youngsters become lively and grow big heads; of course, having a big head equals having a big mouth, which allows the tadpoles to get more food per gulp.
In his research, Relyea happened upon a dramatic side effect of predator risk. He and his colleagues raised gray tree frog tadpoles in water containing a pesticide. Adding a predator to the water rendered the pesticide two to four times as lethal as it was alone. In this era of declining amphibian populations, Relyea and Mills point out that outside the laboratory, predators abound and could be causing pesticides to have an even more deadly effect than expected.
Anyone who has read Herman Melville’s Moby Dick is well aware of the power of the Sperm whale. That denizen of the deep appears to have a nasty habit of ramming its head into whaling ships. Well, a recent scientific study of the whale’s head shows that – surprise, surprise – it is perfectly evolved for ramming ships – or other whales.
You see, a Sperm whale’s forehead contains two sacs filled with oil. But until recently, no one knew just quite what the sacs were use for. Some biologists believe the sacs play a role in sound production; others argue that the sacs help to control the whale’s buoyancy. But another theory says that the purpose of the Sperm whale’s massive oil-filled sacs are to cushion the animal’s head, which can be used as a battering ram in a fight (it’s like two long-horned sheep smashing their curved racks together during a mating battle).
Reporting in New Scientist magazine, biologist Stephen Deban (University of Utah) and his team have modeled how the fluid-filled sacs would behave in such a head-on (or broadside) collision. They found the organ acts like a damper, cushioning the impact. It is a bit like a syringe, said Deban, you do not need much force to push the water out slowly, but you need to squeeze much harder to push it out faster. That means an attacking whale could smash into an opponent’s side – or a ship that might venture into the whale’s territory during mating – and come out of the encounter unscathed.
How does a male humpback whale attract a mate? It sings a looooooong and complex song, which obviously must be akin to telling the female humpback how much he loves her, how much money he has, and what he intends to do to support her. Anyway, this scoop isn’t about the interpretation of the song. It’s about the tune of the song.
Enter the U.S. Navy (and a lot of environmental groups). Navy submarines use a low-frequency, active (LFA) sonar to find their way under water. The problem is that whales can hear this sonar, which is broadcast at a similar frequency to the whale songs. And when they do, they either cut their singing short or continue singing (as if to overcome the noise). In a recent study by the Woods Hole (MA) Oceanographic Institution, researchers found that one quarter of the observed whales cut their songs short in response to hearing the submarine sonar, while others continued singing for a time that was 30 percent longer than normal. At full force, the LFA sonar – recently developed for extended-range submarine detection and opposed by many environmental groups – could cause whales hundreds of kilometers away to "whistle a different tune," and thus affect their chances of mating.
Imagine an elephant’s trunk held up in the air. Now imagine the snorkel on your diving mask. See any similarities? Well some Australian scientists do. In fact, they believe they can prove that elephants were once aquatic animals (they lived in the water) but eventually became land lubbers. If that’s true, then the elephant’s trunk may have evolved as a snorkel.
In fact, the elephant’s trunk might have had multiple uses — nose, hose and tentacle. Studies have shown elephants and those adorable sea cows (like the Florida Manatee) shared a common ancestor. The fossils of Tethytheria, which include the ancestors of elephants and manatees, point to an aquatic lifestyle as well. Zoologist Ann Gaeth and colleagues from of the University of Melbourne in Australia examined a series of African elephant specimens in various stages of development.
Here’s what they found: The male fetuses had testicles growing inside the abdominal wall, rather than in a scrotum — a development suggesting they evolved in the water and then moved onto land. The elephants had funnel-shaped kidney ducts used to flush waste through the abdominal lining — features common to freshwater animals, such as fish and frogs; the presence of these ducts imply that elephants may have developed in a freshwater environment. Finally, there’s the trunk, which could have been used as a snorkel for swimming in deep water. The team reported their findings to the National Academy of Sciences. Further research will reveal if there’s anything fishy going on here.
No. This scoop isn’t about looking around the lunchroom and spotting who’s eating beef and who’s nibbling sprouts. But it is about how carnivores of the wild kingdom are marked with spotted or lined facial patterns. Alessia Ortolani of the University of California believes that breaking the code of these facial patterns will give her more insight into how animals have communicated over history. That’s right, communicated — just as warriors put on facial paint.
In her analysis of 200 terrestrial carnivores, for instance, Ortolani has discovered that white markings around the eyes (like the crescents under a tiger’s eye) often appear in the family tree of nocturnal predators (those that hunt at night). The white marks may have helped carnivores over the years distinguish friends from foes. So the white crescents are a kind of "neon" message, flashing out in the dark, saying something like "Eat at Joe’s . . . not on me." But, this is just the beginning of Ortolani’s research. She still has a lot of data to chew on before she can offer any more findings.
The gecko is a little lizard that can scale a flat wall, dash across the ceiling, or run across a glass wall, stop suddenly, then hang from one digit, if it pleases. The gecko: a living Post-It. How does it do it, all that scampering around on slippery surfaces? It’s a mystery that’s been, well, driving researchers up the wall.
But after a decade of sticking together in research, Kellar Autumn (Lewis and Clark College), Robert J. Full (University of California at Berkeley) and their colleagues began hugging each other over a monumental breakthrough in lizard science. You see, the researchers have finally figured out the gecko’s secret adhesive doohickey. No suction here, just an attractive force that occurs at the molecular level – when the distance between the tiny hairs on the gecko’s foot and the smooth surface it’s on becomes no more than the diameter of one atom. Wow!
It turns out that a gecko’s foot has about half a million microscopic hairs, or setae, each of which splits into hundreds of teeny pads, which in turn hug the surface so closely that they interact with its molecular structure. If all its setae operated at once and at full force, the gecko could carry a weight of 40 kilograms. The pads break the attractive force when they are tipped at an angle of 30 degrees. To "peel off," the gecko performs a delicate but swift operation of toe uncurling. Geckos can attach and detach their feet an amazing 15 times a second when running. It’s possible that some kind of watery interaction also plays a role in the way a gecko can cling to any surface.
If these researchers can fully understand how the gecko’s setae system works, we might soon expect to find in stores some kind of gecko glue — a dry adhesive modeled after gecko feet.
Here’s a question for you to ponder. How did life survive the Great Ice Age 600 to 800 million years ago? If you don’t know the answer, don’t feel bad. Scientists didn’t know either, until recently that is. Now scientists from Canada and America believe they have the answer. They used calculations and climate models to show there may have been areas of open water that allowed early creatures to live while the rest of the planet was in a deep freeze. "This could help clarify how multi-celled animals managed not only to stay alive but to thrive given the Earth’s harsh conditions," says Richard Peltier, a physics professor at the University of Toronto.
Using computer simulations of what are thought to have been the climate characteristics at the time, and taking into account less sunlight and the varied concentrations of atmospheric carbon dioxide, Peltier and his colleagues found that the harsh climate could have given the creatures an evolutionary push. "The extreme climates may even have exerted pressure on the multi-celled animals to evolve and adapt, possibly leading to the rapid development of new forms of animals and their movement into new, unpopulated habitats when the Earth exited the snowball state," Peltier said.