It’s Good To Look Like Poo February 22, 2008
Posted by Mrs Weird Scientist in Animals, Insects, Tough Stuff.Tags: butterfly, camouflage, caterpillar, poo
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Sometimes, it’s great to look like poo. That is, if you’re a caterpillar! Say hello to the Asian swallowtail caterpillar. It has some neat tricks up its sleeve to successfully stay camouflaged from predators. The first trick comes into play quite early on – when the caterpillar is black and white, with fine spines. Here, it resembles bird droppings. Later on, the caterpillars get older and grow larger, which means it’s a lot harder for the caterpillars to pass themselves off as bird poo. So, as the little critters fatten up, their color changes to a vivid green. Hmmm. Why might being green work well as a camouflage? If you guessed it’s because they can blend in with the leaves, you got it!
Credit: Ryo Futahashi. You can see the wee caterpillar on the left side of the picture looks a lot like bird droppings! On the right, the distinguished fellow is a grown caterpillar – the bright, green color really does make the caterpillar look like the surrounding leaves.
Manipulating The Caterpillar’s Camouflage
In an interesting twist of events, Ryo Futahashi and Haruhiko Fujiwara of the University of Tokyo in Japan, discovered a special way to keep the caterpillar looking like bird droppings. This means that the caterpillar still matures and develops, but it retains its poopy camouflage instead of growing into a green caterpillar that resembles leaves. How did the researchers accomplish this task? It’s not so easy.
It’s All About Genes
You might already be familiar with the concept of genes. Your genes are unique instructions that tell your body how to work. They control all sorts of stuff such as your hair or eye color. Humans aren’t the only ones with genes either! Caterpillar camouflage depends on genes. There are three genes that control the caterpillar’s camouflage. One is responsible for the green color, another for the black color and finally, one for those spikes we see on the very young caterpillars.
Tinkering With Genes
If researchers can find a way to meddle with these genes, they can change the caterpillar’s color. Hint hint. In the case of our Japanese scientists, they did their meddling with a hormone that rules the expression of all three genes. It’s called juvenile hormone. Researchers smeared a synthetic version of juvenile hormone on the back of a young caterpillar. Since the hormone controls the three genes that affect the caterpillar’s color, adding more of the hormone managed to keep the caterpillar looking poopy right through its development. It’s a cool manipulation because it teaches us more about how hormones and genes interact. As for all this talk about poo, I think my next blog post will be on something a bit more pleasant!
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A Bit Of Gorilla Love February 20, 2008
Posted by Mrs Weird Scientist in Animals, Evolution, Psychology and Behavior, Think About It.Tags: behaviour, copulation, gorillas
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It seems that primates have gotten a lot closer. Not only have researchers recently observed primates in the wild- specifically gorillas – copulating face-to-face, but they have captured the first known photographs of the surprising event. Why surprising? It’s because very few primates actually mate in the face-to-face position. There is also a neat, complicated word for it called ventro-ventral copulation. It makes all of this gorilla lovin’ sound like a very technical act! What is the usual position for primates? Well actually, the majority of primates copulate in the dorsal-ventral position. This means that both primates are facing in the same direction.
Credit: Thomas Breuer – WCS/MPI-EVA. The female gorilla in the photo was nicknamed ‘Leah’ by researchers. She’s also familiar to researchers, who originally observed her in 2005 when she tested the depth of a pool of water with a stick, before splashing her way into it. This action was also considered unusual behaviour for a gorilla, which has piqued the interest of researchers even more. I think Leah sounds like a cool lady who likes to do things a bit differently!
Ready, Set, Camera Action
The study was led by Thomas Breuer of the Wildlife Conservation Society (WCS) in cooperation with the Max Planck Institute for Evolutionary Anthropology (MPI-EVA). The findings were published in the Gorilla Gazette. If you’re wondering where these pictures were taken, they were snapped in all their glory at the Nouabalé-Ndoki National Park in the Republic of Congo. According to Breuer:
Our current knowledge of wild western gorillas is very limited, and this report provides information on various aspects of their sexual behavior. We can’t say how common this manner of mating is, but it has never been observed with western gorillas in the forest. It is fascinating to see similarities between gorilla and human sexual behavior.
It’s also worth noting that other than humans, only a handful of animals have been observed mating face-to-face. These include bonobos and the observation of gorillas in captivity although none were ever photographed.
What’s The Big Deal?
You might be thinking to yourself that scientists are really peculiar (if you didn’t think so already!) to care about animal copulation or to even be taking pictures of animals mating. Think again! It actually does matter. Since gorillas are considered ‘cousins’ to humans, learning more about their behavior helps us to understand the evolutionary development of our own species. Speaking of our species, I almost considered being a typical lovey dovey girl by putting a red heart in above the gorilla picture!
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A Crafty Disguise February 6, 2008
Posted by Mrs Weird Scientist in Animals, Evolution, Insects, Tough Stuff.Tags: birds, fruit, nematode, parasite
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A very tricky parasite has recently been discovered. What makes it so sneaky? After infecting a certain species of ant known as Cephalotes atratus, the parasitic nematode triggers changes in the ant’s abdomen, which then becomes red and swells. This bulging, red appearance resembles a berry. Birds who feed on this type of fruit mistake the ant for a berry, swoop in and gulp! The bird swallows the ant, which allows the parasite to now infect the bird. Once birds are infected, the parasite can spread through the birds’ feces. In a bizarre circle of events, the ants round off the infectious cycle by gathering up the birds’ droppings so that they – along with their young – can feed off the feces. Smart parasite! It manages to sustain itself through the host ant so it can infect the unsuspecting birds – who think they’re about to eat a juicy, luscious berry!
Credit: Steve Yanoviak of the University of Arkansas. Check out the normal worker ant in the top picture and then compare it to the picture below it, which shows an ant infected with a parasitic nematode. That is one seriously red abdomen! It will be the doom of the ant when a bird mistakes it for a yummy, red berry.
Welcome To The Amazon
This peculiar cycle was observed in the tropical forests in the Amazon and Central America. Robert Dudley of the University of California – Berkeley described his surprise at finding such an intelligent series of events:
It’s just crazy that something as dumb as a nematode can manipulate its host’s exterior morphology and behavior in ways sufficient to convince a clever bird to facilitate transmission of the nematode.
The discovery itself was a chance one as Dudley, Yanoviak and Michael Caspari of the University of Oklahoma were observing a gliding species of ant. They noticed that some of the colony members had bright, red abdomens. Normally, birds don’t even eat ants – partly because of their yucky chemical taste. Yanoviak had some cool things to say about this fascinating discovery:
It’s phenomenal that these nematodes actually turn the ants bright red and that they look so much like the fruits in the forest canopy.
The full article describing the fruit mimicry will be published later this year in the journal American Naturalist. It might be worth a wee read to get the entire scoop on this amazing discovery. Also, research like this doesn’t go without funding – it was partially supported by the National Geographic Society, Amazon Conservation Association and the BBC Natural History Unit.
Evolution
I’m absolutely amazed at the findings. It’s incredible that something as seemingly simple as a nematode can manipulate the ants in such a successful way. It just goes to show that whether a creature is simple or complex, evolution can be one smart cookie!
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Eat Or Be Eaten February 5, 2008
Posted by Mrs Weird Scientist in Animals, Easy As Pie.Tags: battle, food, snakes
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Credit: National Geographic.
You might want to eat your lunch before watching this video. It could put a dampener on your appetite. That is, unless your taste buds are a fan of scales!
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A Self-Destructive Mosquito Bite January 18, 2008
Posted by Mrs Weird Scientist in Animals, Diseases, Human Body, Insects, Think About It.Tags: insecticide, malaria, mosquito
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A mosquito’s bite usually has a characteristic sting, but the pain subsides and at worst, most of us experience a bit of swelling, itching and redness for a few days. For some people, however, a mosquito’s bite can bring with it some lasting discomfort – namely when the mosquito is carrying a disease such as malaria, yellow fever or West Nile virus – among others. The good news is that researchers from the University of Arizona in Tucson may soon have a way to make the mosquito’s bite deadly to itself!
Figuring It Out
Researchers recently discovered something very peculiar. When a mosquito species known as Aedes aegypti gorges on human blood, it excretes a substance called nitrogen immediately afterwards. The nitrogen is toxic to the mosquitoes and must be released following its meal. What happens if the mosquito doesn’t excrete the nitrogen? Bam! Self-destruction! If the mosquitoes don’t excrete the nitrogen, they will not lay eggs and will most likely become ill and die.
Taking Advantage Of Nature
By taking into account this complicated metabolic pathway of the mosquito, researchers are now looking for a molecule that won’t harm humans but will basically muck up the metabolic pathways of mosquitoes, which means they’ll retain their nitrogen and effectively self-destruct. Once the researchers have figured out the mechanics of the molecule, they can then develop an insecticide and spray it in the areas where mosquitoes like to play – around the water, for example.
According to the lead researcher Roger Miesfeld:
Our goal is to turn the female mosquito’s blood meal into the last meal she ever eats. The whole community would essentially become one big mosquito trap. It would be a group effort that in the long run could have a huge impact. This would be one more weapon in our arsenal against diseases that kill millions of people a year.
Another potential application would be an oral insecticide. So, if you lived in an area where a disease such as malaria is prevalent, you could take a pill that would cause the mosquito to ingest the insecticide along with your blood. This wouldn’t prevent you from actually getting the disease but it would kill the mosquito after it bites, which means the spread of disease could be slowed.
I find it easy to forget just how potentially dangerous a mosquito’s bite can be, mostly because I am either living in North America or the United Kingdom, where the risk of disease from mosquitoes is fairly small. Yet, for many people, diseases passed through mosquitoes are a frightening reality. Hopefully, this new research can help to reduce the mosquito population and prevent both the initial sting and the spread of diseases.
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Attracting True Love: Crabs Show How It’s Done January 15, 2008
Posted by Mrs Weird Scientist in Animals, Think About It.Tags: communication, fiddler crabs, love, mating
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Credit: Martin How, ANU. A fiddler crab prepares to captivate his true love!
When it comes to love, you might be surprised to learn that crabs have some similar behaviours to humans. A study led by Martin How from the Australian National University (ANU) has found that crabs change their behaviour depending on the distance between them and their true love. The full study results can be seen in the journal Animal Behaviour.
Meet The Fiddler Crabs
Credit: Martin How, ANU. A male fiddler crab does some charming claw-waving to get the attention of a female fiddler crab. Hmmm. I wonder if the lady crab will approach!
Fiddler crabs – formally known as Uca perplexa – are tiny crabs that reside on mudflats near North Queensland, Australia. Observation of the fiddler crabs showed some interesting behaviour. How spent two weeks observing and filming the fiddler crabs. Think about how humans try to get attention from someone they like. Sometimes – if the person is far away – they might wave their hand to catch that person’s attention. The fiddler crabs have a similar way of communicating. A fiddler crab will wave his large, colorful claw! According to How:
We know that in everyday life, attracting the attention of a distant person involves gestures and vocalisations different from those used when that person is nearby.
The crab’s behaviour gets even more specific. When the female crab moves closer, the male crab changes the movements of his claw. How explains:
Over distance he uses these very flamboyant, very conspicuous claw-waving displays, ‘I’m over here come and see me.’ When the female approaches very close, he adjusts those displays so they are less broad and flamboyant and more coaxing.
So basically, the male crab has to make some obvious gestures to get the female crab’s attention. Once he has that attention, however, he can be more subtle.
Credit: Martin How, ANU. A fiddler crab shows off his moves – he waves his brightly colored claw to impress the female crab.
Crabs Like To Show Off
Not only do the male crabs have this interesting array of behaviours to gain attention from the female, but they also like to do some showing-off as well! This showing-off includes raising his body off the ground, performing some brag-worthy unflexed leg lifts and of course – the grand finale – the slow claw lift. How suggests that this is the male crab’s way of showing off his special qualities in hopes of convincing the female to follow him into his burrow to mate.
So really, the study tells us that whether it’s crabs or humans, animals use all sorts of special tricks and gestures to attract a mate. If only I had a colorful claw to wave when I wanted to get someone’s attention! I suppose I will have to make do with painting my fingernails.
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An Enormous Scorpion Claw January 4, 2008
Posted by Mrs Weird Scientist in Animals, Environment, Evolution, Ocean, Think About It.Tags: claw, fossil, scorpion
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Scorpions today are big enough in terms of the sting they can pack from their fairly small bodies. Have you ever wondered what it would be like if they were even bigger? Well, imagine no more because new evidence indicates that this may indeed be the case. A massive fossil claw of a scorpion was recently found in Germany and it suggests that ancient arthropods – including spiders and crabs – were a lot bigger than their modern day versions.
An Incredible Discovery
The claw of this very old scorpion – formally known as Jaekelopterus rhenaniae – was found by Markus Poschmann of Yale University. The scorpion is part of a group which comprises some of the largest extinct arthropods. The massive extinct scorpions are believed to be ancestors of modern scorpions. Poschmann has now co-authored a report with Erik Tetlie, a postdoctoral associate who is also at Yale. The report – published online in the Royal Society Biology Letters – details the incredible discovery. According to Tetlie:
Imagine an eight-foot-long scorpion. The claw itself is a foot-and-a-half long – indicating that these ancient arthropods were much larger than previous estimates – and certainly the largest seen to date.
Lead author Simon Braddy described the excitement of the discovery:
This is an amazing discovery. We have known for some time that the fossil record yields monster millipedes, super-sized scorpions, colossal cockroaches, and jumbo dragonflies, but we never realized, until now, just how big some of these ancient creepy-crawlies were.
Credit: Braddy et al. Royal Society Biology Letters. The images to the right put an awesome perspective on the size of the ancient sea scorpion. The images show the reconstructed fossil claw of the ancient sea scorpion Jaekelopterus rhenaniae (e) and its size relative to a human male and to the sea scorpion (a), the trilobite Isotelus rex (b), the dragonfly Meganeura monyi (c), and the millipede Arthropleura armata (d). I will sum up my impression with two words: Wow! Eeeeep!
Fossils Yield Clues
The change in size of arthropods is one of those things that gets geologists scratching their heads and debating over how this change occurred. Evolution can definitely get scientists and the rest of us wondering just what happened to trigger the change.
Tetlie described some of the theories shared in the debate:
While some believe they evolved with the higher levels of atmospheric oxygen that were present in the past, some say they evolved in a parallel ‘arms race’ with early armored fish that were their likely prey.
Whew!
Personally, I’m quite pleased that these crawling critters aren’t the jumbo-sized creepies they were millions of years ago. Despite my curiosity and interest in scorpions, I still yelp in fear if I encounter one in my travels!
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Honeybees Aren’t Always So Sweet January 3, 2008
Posted by Mrs Weird Scientist in Animals, Easy As Pie, Insects.Tags: bees, hornet, wasps
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Credit: Papachristoforou et al. for New Scientist.
I have an interesting and sometimes rocky relationship with the buzzing creatures we call bees and wasps. Like some people, I retreat when I see the odd bee nearby – even as I take care to avoid being stung.
At one point in time, I even developed an intense fear of wasps. What triggered my fear? I lived in a top floor flat in Scotland for a year. During this time, a wasp’s nest emerged, which was likely somewhere near the building. Despite calls to my landlord – who had workers searching for the elusive nest – nobody could find the exact location of these persistent insects. For weeks, I (along with my similarly frustrated neighbors) had wasps coming in from every nook and cranny around the windows and vents. I remember sitting at my laptop, attempting to type up a laboratory experiment while wasps perched on my curtains, flew around my lights and generally had me grumbling at the presence of these new, unwanted flatmates. A visit from a local handyman resulted in duct tape all around any openings in the flat, which ultimately sealed me in the flat and kept the wasps out!
Fortunately, enough time has now passed that I am more fascinated than fearful of these little creatures. I saw this video recently and wanted to share it here on the weird science blog. In this video, loads of Cyprian honeybees swarm around a hornet to suffocate their enemy. Trust me – when I say swarm, I mean it!
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You’re Not The Only One Who Laughs January 2, 2008
Posted by Mrs Weird Scientist in Animals, Evolution, Psychology and Behavior, Think About It.Tags: ancestor, empathy, laughter, orangutans
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If you thought humans were the only ones who laughed, think again. A new study has suggested that the roots of laughter might have stemmed from a primate ancestral to humans and modern apes. Researchers discovered that orangutans not only mimic the facial expressions of laughter but they also have a sense of empathy that is an important part of laughter.
Open Wide
Think about the types of expressions you make when having a good laugh! For most of us, we open our mouths and then emit all sorts of happy noises (some a bit stranger than others!). Orangutans have an open-mouthed expression that is their version of human laughter.
In a study led by Davila Ross from the University of Portsmouth, England and Elke Zimmerman of the University of Veterinary Medicine in Hanover, Germany, observation of the play behavior for 25 orangutans showed some interesting results regarding their facial expressions. The gaping, wide mouth that can occur during laughter was seen and copied by orangutans. If one orangutan showed a gaping mouth, another would quickly do the same. On top of that, they picked up the expressions so rapidly that it seems these expressions are involuntary. What do you think that means? Laughter is contagious!
So, not only are humans’ good moods contagious, but the moods of orangutans are too. The finding is particularly neat because it shows that our orangutan relatives also experience empathy. Plus, it suggests this trait evolved from a common ancestor. Laugh, and the whole world laughs with you. At least, the phrase is true for humans and orangutans!
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Dinosaur Breath Tells Secrets November 14, 2007
Posted by Mrs Weird Scientist in Animals, Dinosaurs, Environment, Evolution, Think About It.Tags: birds, breath, respiratory
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Sssssssh. Believe it or not, dinosaur breath can tell us quite a bit about how dinosaurs evolved and what sort of life they experienced. Led by Dr Jonathan Codd, a team at the University of Manchester in the United Kingdom did some investigating and found that theropod dinosaurs had respiratory systems that were similar to modern marine birds and wildfowl. If you’re not too well versed in dinosaur lingo, then ‘theropod’ might be a new word for you. Theropods were the quick-moving, massive, mostly carnivorous dinosaurs that roamed Earth. They also had powerful legs and clawed hands. The results of the investigation are really cool because they give us some insight into how dinosaurs actually breathed. The full details of the research were published in the Proceedings of the Royal Society B: Biological Sciences.
Credit: Jonathan Codd of the University of Manchester. Let the battle begin! This picture shows a Protoceraptops fighting it out with a Velociraptor mongoliensis. The lengthy uncinate processes can be seen on the rib cage of the velociraptor.
I Knew That
There already are studies showing that dinosaurs were the direct ancestors of birds but scientists are still trying to find out to what extent anatomical features are shared. So, even if you already knew that there were a bunch of avian characteristics in dinosaurs, there is still lots to learn as new features are identified – like dinosaur breathing structures! Much of what we know is built upon heaps of studies. We basically keep adding new information to the pot – sometimes this information makes us say ‘Wow, the old idea was way off!’ Other times it extends what we know by explaining it in more detail. In this case, we’re simply adding new information to the mix!
Breathe In, Breathe Out
Inhale and exhale! We already know that birds – especially diving birds – have really well functioning respiratory systems. In fact, they have one of the most efficient systems of vertebrates. Why so efficient? It’s because they need loads of oxygen to keep up their constant flying. They have special breathing structures called uncinate processes. After looking at fossilized remains of dinosaurs and birds, the researchers found that uncinate processes were also present in dinosaurs. Codd talked about how dinosaur breathing is more specialized than was first believed:
Our work on modern birds has shown that the way these animals breathe is more complex than originally thought. The uncinate processes are small bones that act as levers to move the ribs and sternum during breathing. Interestingly, these structures are different lengths in different birds – they are shortest in running birds, intermediate in flying birds and longest in diving birds.
The dinosaurs we studied from the fossil record had long uncinate processes similar in structure to those of diving birds. This suggests both dinosaurs and diving birds need longer lever arms to help them breathe.
Finding these structures in modern birds and their extinct dinosaur ancestors suggests that these running dinosaurs had an efficient respiratory system and supports the theory that they were highly active animals that could run relatively quickly when pursuing their prey.
Ultimately, the uncinate processes allowed the dinosaurs to move around very fast, which meant they could rapidly capture prey. Right now though, you’re probably breathing a sigh of relief that this article wasn’t about bad dinosaur breath! With all the raw meat they ate, I have a feeling it would have been really gross. Yuck!
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