Archives for category: science


Mimicry is an art.

Human seeks to mimic animal call, other humans, a certain repertoire for the purpose of hunting, defence, or simply to entertain. But even a seasoned mimicry artist of our world would have paled in comparison to some of the masters of mimicry of the animal kingdom.

For them, mastering the art of mimicry is a matter of life or death.

A Stick Insect. Image:http://en.wikipedia.org/wiki/Phasmatodea

Most animals mimic to defend themselves. Some to attract mate, and some, for example chameleons
and alligator snapping turtles mimic(or camouflage) for food.

An Alligator Snapping Turtle. Image: http://www.itsnature.org

Yesterday I read this article about a phorid fly, Vestigipoda longiseta, from southeast Asia, that mimics ant larvae.

Image:http://whyevolutionistrue.wordpress.com/2010/09/24/adult-fly-mimics-ant-larva/

The long “grubworm” part of the body is simply the enormously elongated and unpigmented abdomen of the adult. This has all evolved from an ancestor that looks pretty much like the flies you know.

You can imagine why natural selection would favor this resemblance: the ants tend and feed the larvae, and mistake the flies for their own brood. It’s a lifetime of free lunches! The ants also protect the flies and carry them (like they carry their own larvae) when a colony is on the move.

An adult of V. longiseta being carefully carried by an Aenictus ant. Image: http://whyevolutionistrue.wordpress.com/2010/09/24/adult-fly-mimics-ant-larva/

Why can’t the ants detect these intruders? Well, they’re not terribly harmful, getting just a bit of food from the colony, so there’s probably not strong selection to weed them out. Ants, of course, have pretty bad vision, so they probably can’t see the intruders as different from their own brood. There’s probably chemical mimicry going on here as well: the hydrocarbon molecules on the fly’s cuticule may well resemble the compounds on ant larvae, so that the ants, who “taste” these hydrocarbons, are fooled by chemical mimicry.

Another master of mimicry that I would like to introduce to you all is the Mimic Octopus. Read my previous post~

A Mimic Octopus. Image: zmescience.com

And another one which really amazes me is the Superb Lyrebird. I remember watching a video about the mimicry power of this bird when I was in Form 2, and I thought it was fake. Given the handicapped technology of that time, and the level of maturity of the audience, I was unable to record the episode for further review.

A Superb Lyrebird. Image:cae2k.com

Nevertheless, I found this video on youtube yesterday. Watch as Sir David Attenborough (Sir David Attenborough is a fantastic naturalist; down-to-earth, full of knowledge, a titan of science) relates the ability of this bird to mimic the call of every other birds, including other sounds it hears: chainsaw, camera shutter, cars… FOR REAL!


A planthopper mimicking a leaf. Image:http://en.wikipedia.org/wiki/File:Mimicry_of_Siphanta_acuta_edit1.jpg

Image:falkenblog.blogspot.com

Image:http://conservationreport.com/2008/11/08/

Caterpillar mimicking a snake to scare off birds. Image: http://www.amnh.org

Dead-leaf butterfly. Image:http://conservationreport.com/2008/11/08/

Have you ever wondered how insects, especially small ones like mosquitoes and flies survive the downpour?

Raindrops pose hazard to mosquitoes because of their relatively large mass and speed. A mosquito is around 2~5mm in length, weighs around 2mg, and flies at 1m/s. On the other end, a drop of rain has 1~4mm radius, weighs 2~50 times the weight of a mosquito, and travels at 5~9m/s. Putting that into perspective, it’s like us getting hit by a blob of water with the size of a shopping cart, weighs 3 tons and travels at 18~32 km per hour.

It’s an irony that the delicate blood-sucking parasite thrives in wet, rain-laden tropical country like Malaysia. Wouldn’t they be crushed to death by the raindrops?

Image: en.wikipedia.org

Mechanical engineer David Hu of the Georgia Institute of Technology who thought of this question placed some mosquitoes in a cage and exposed them to water drops. Slow motion footage showed that rather than dodging the water drops, the insect flew right into the them.

Since the mosquitoes were so lightweight, the raindrops lost very little momentum upon impact. By minimizing resistance, the insect minimized the impact of collision. So instead of flattening the insect, the water drops simply spun the mosquitoes away, though the insects recovered soon afterward.
It’s like an asteroid hitting a piece of paper: the paper is so lightweight that it’s just pushed aside.

And nature has given mosquitoes a helping hand: mosquitoes are designed to be hydrophobic, thanks to the hairs on the mosquitoes’ body. The hairy surface increases the wing’s surface area, and thus its energetic cost of wetting. Thanks to this hydrophobicity, low speed drops simply bounce off the insect.

Image: rationaldiscoveryblog.com

Moreover, insects are blessed with hard exoskeleton to help them withstand the impact. And mosquitoes could withstand sudden acceleration of up to 300Gs. If we were in a comparable situation we wouldn’t even survive past 2Gs.

Thanks to its tiny weight and hydrophobicity, the evil parasite lives to suck another victim.

info:
http://www.youtube.com/watch?v=XWyoy44oV3Q
http://discovermagazine.com/2012/mar/31-how-mosquitoes-survive-in-a-downpour
http://inkfish.fieldofscience.com/2012/06/why-you-cant-kill-mosquito-with.html


The Pufferfish is considered the second deadliest vertebrate in the world, after the Golden Poison Frog. The common image we have of this creature is that it inflates when threatened. I have kept these fish in an aquarium, and in my experience they rarely puff out in captivity.

What makes the Pufferfish, also called the Fugu so popular is the lethal toxin in its liver, skin and the ovaries, and the fact that the Japanese treat it as a delicacy. Pretty ironic I guess? By the way it is extremely expensive and prepared only by trained, licensed chefs who, like all humans, occasionally make mistakes.

Image: blogs.bootsnall.com

Almost all pufferfish contain tetrodotoxin, a substance that makes them foul tasting and often lethal to fish. To humans, tetrodotoxin is deadly, up to 1,200 times more poisonous than cyanide. The toxin paralyzes the muscles, including the muscles in our diaphragm, which is essential for breathing. The victim eventually dies of asphyxiation. There is enough toxin in one pufferfish to kill 30 adult humans, and there is no known antidote. Tetrodotoxin has been isolated from widely differing animal species, including western newts of the genus Taricha (where it was formerly termed “tarichatoxin”), pufferfishtoads of the genus Atelopus, several species of blue-ringed octopuses of the genusHapalochlaena (where it was called “maculotoxin”), several sea stars, certain angelfish, a polyclad flatworm, several species of Chaetognatha (arrow worms), several nemerteans (ribbonworms) and several species of xanthid crabs.


Tetrodotoxin molecule


Image: gastroville.com

Negative aspects aside, Puffer Fish makes cute companion.

Of course, don’t go around scaring puffer fish because a puffer fish could only perform a limited number of inflation in its life.

Image: animals.nationalgeographic.com

When a Pufferfish is threatened, it will pump itself up by taking 35 gulps or so in the course of 14 seconds. Each gulp draws in a big load of water thanks to some peculiar anatomic changes in the muscles and bones. The entire fish balloons as it continuously takes water into its stomach.

The stomach expands to nearly a hundred times its original volume, and the fish’s spine, already slightly curved, bends into an upside-down U shape, and all other internal organs become squeezed between the fish’s backbone and its rapidly expanding stomach. Meanwhile, the fish’s skin is pushed out, obscuring most of the puffer’s features-http://divingintaganga.blogspot.com/2010/09/how-and-why-pufferfish-inflate.html

Image: Sally J. Bensusen. American Museum of Natural History.

Sometimes they have difficulties expelling water from their stomach, and hence they actually risk dying every time they inflate. I guess we should record a default video showing one individual inflating itself on a public website to prevent curious divers/swimmers/fishers going around harming more Pufferfish. Pufferfish belong to family Tetraodontidae is a family of primarily marine and estuarine fish of the order Tetraodontiformes. The family includes many familiar species, which are variously called pufferfishpuffersballoonfishblowfishbubblefishglobefishswellfishtoadfishtoadies,honey toadssugar toads, and sea squab. They are morphologically similar to the closely related porcupinefish, which have large external spines (unlike the thinner, hidden spines of Tetraodontidae, which are only visible when the fish has puffed up). The scientific name refers to the four large teeth, fused into an upper and lower plate, which are used for crushing the shells of crustaceans and mollusks, their natural prey.

With all of this, many people still consider Fugo to be a delicacy , especially in Japan.


info:
http://www.aquaticcommunity.com/predatory/pufferfish.php
http://en.wikipedia.org/wiki/Fugu
http://divingintaganga.blogspot.com/2010/09/how-and-why-pufferfish-inflate.html

How does a firefly produce it’s glow?



The simplest answer would be bioluminescence. But that alone doesn’t explain the mechanism and the rationale of exposing your whereabouts to potential predators at night.

Fireflies are familiar, but few realize that these insects are actually beetles, nocturnal beetles. Most fireflies are winged, which distinguishes them from other luminescent insects of the same family, commonly known as glow worms.
Glow worm. Image:barryjnorthern.blogspot.com
There are about 2,000 firefly species, thriving in a variety of warm environments, as well as in more temperate regions. Fireflies love moisture and often live in humid regions of Asia and the Americas. In drier areas, they are found around wet or damp areas that retain moisture.
Image: animals.howstuffworks.com
Fireflies have dedicated light organs that are located under their abdomens. The insects take in oxygen and, inside special cells, combine it with a substance called luciferin to produce light with almost no heat. Wow.

Firefly light is usually intermittent, and flashes in patterns that are unique to each species. Each blinking pattern is an optical signal that helps fireflies find potential mates, though we aren’t sure exactly how the insects regulate this process to turn their lights on and off.
Image: animals.howstuffworks.com
Firefly light may also serve as a defense mechanism that flashes a clear warning of the insect’s unappetizing taste. The fact that even larvae are luminescent lends support to this theory. Females deposit their eggs in the ground, which is where larvae develop to adulthood. Underground larvae feed on worms and slugs by injecting them with a numbing fluid. Adults eschew such prey and typically feed on nectar or pollen, though some adults do not eat at all.


Why do fireflies glow?

One reason that fireflies glow is to attract a mate. Males and females of the same species will flash signals back and forth as a way of communicating. Each firefly species has its own particular pattern. For example, the fireflies of one species will fly around in the night sky and dive steeply just as the flash begins and turn upward to make a distinctive J-shaped pattern of light. Female fireflies hang out on a tree branch or in the grass while the males fly around showing off their best flashes. When a female recognizes the flash from a male of the same species, she will answer with her best flash.

Another reason that fireflies glow is to avoid predators. Fireflies are filled with a nasty tasting chemical called lucibufagens, and after a predator gets a mouthful, it quickly learns to associate the firefly’s glow with this bad taste! So not only does the flashing help attract a mate, but it also warns predators to stay away.


Other creatures with bioluminescence.

Other glowing animals would be those eerie-looking deep sea dwellers; angler fish, and certain species of shrimp and plankton.
Angler fish. Image: animals.nationalgeographic.com
Image: lukaj.net
info: 

No, no. They don’t form anything like the Hulk, and definitely won’t form a super-molecule containing one of everything.

There are two methods of putting it to the test, neither of which are practical.

The first method would require energy equivalent to dozens of Large Hadron Colliders-an impressive and extremely treacherous experiment indeed. The second method would be putting together a chunk of each element and observe what happens.

Both, however, would eventually create carbon monoxide and a pile of rust and salts rather than a cool Frankenstein element.

Image: blackchristiannews.com

Atoms are made up of a nucleus of neutrons and protons with a set number of electrons circling around them. Molecules form when atoms’ electron orbitals overlap and effectively hold the atoms together. What you get when you mix all your atoms will be influenced by what’s close to what.
Oxygen, for example, is very reactive, and if it is closest to hydrogen, it will make hydroxide. If it is nearest to carbon, it will make carbon monoxide. Certain elements, such as the noble gases, wouldn’t react with anything.
Bombarding the atoms together at 99.999 % the speed of light in the Large Hadron Collider might be able to break protons, but it could also be used to fuse a few nuclei together. But still it won’t produce anything supernatural-and if there’s any, it would probably decay into something more common in a fraction of a second. Moreover, you would need 118 colliders-one to accelerate each element in the Periodic Table to get the task done, which sounds pretty quixotic to me.

Image: scienceblogs.com


Another approach would be to toss a pulverized chunk of each element or a puff of each gas into a sealed container and observe the consequence. No one has ever tried this experiment either, but here’s how scientists think things would play out: The oxygen gas would react with alkaline metal (lithium or sodium) and ignite, raising the temperature in the container to the point that even Devil himself would complain. There are roughly 25 radioactive elements, and they would make your flaming stew a little dangerous. Flaming plutonium is a very bad thing-inhaling airborne radioactive material can cause rapid death.
Once temperature drops, the result would be as boring as the atoms-only scenario. Carbon and oxygen would yield carbon monoxide and carbon dioxide. Nitrogen gas is very stable, and would remain as is. The noble gases wouldn’t react, nor would a few of the metals, like gold and platinum, which are mostly found in their pure forms. The things that do react will form rust and salts. 



Some smaller level reactions can be shown here with cool videos. Take water and sodium. Two things we have at home, maybe even on the dinner table. Sodium in its elemental form is highly reactive to water.

Check out this video: Sodium v Water (slow motion) – Periodic Table of Videos


 Zinc and sulfer another another fantastic combo.   Zinc and Sulfur – Periodic Table of Videos 
Of course not just sodium reacts with water.  So does potassium.  



REFERENCES:
info: http://www.popsci.com/science/article/2010-10/fyi-what-would-happen-if-every-element-periodic-table-came-contact-simultaneously

Man’s best friend.

A dog can do anything; from saving lives to sniffing out drugs, helping others to hunting for food,  our canine friends are more than mere companion.


Many of us have dogs at home. Some people love their pet so much they allow the animal to venture into home and bedroom. But we all know that dogs are the direct descendants of the Gray Wolf.



Some said that early humans adopted wolf pups and that natural selection favored the less aggressive and better at begging for food animals. Others said dogs domesticated themselves by adapting to a new niche—human refuse dumps. Scavenging canids that were less likely to flee from people survived in this niche, and succeeding generations became increasingly tame.

Wolves and people have several things in common.
Firstly, we were both hunters and also hunted in packs. It was certain that during the course of our evolution our paths would have regularly crossed, we would have even hunted and eaten each other. That’s the beginning of our relationship with our canine friends.

Wolves live in packs, headed by an Alpha male and Alpha female. The Alphas are the most aggressive couple in a pack, and the only pair that breeds. The resulting cubs will be taken care of by all members of the pack. Other wolves involve in hunting and the cubs’ protection, but never allowed to breed. While generally accepted this particular theory has fallen out of practice.  In fact canine society is a bit more complex than merely an ‘alpha’ dog.  There certainly is an alpha, but along with other dynamics and behavioral complexities, a pack dynamic is formed.  With humans it takes more than being an alpha, the dog must have trust and loyalty.

Upon reaching maturity, the young wolves will be driven out from the pack to start a pack of their own. They must venture out from the packs’ territory to avoid future confrontation, sometimes as far as 30-40 kilometers away.
There are, however, weaker and less aggressive members of the pack. They get the least food during hunting. However some altruistic wolves allow the smilers pack mates to eat first.  Why? It is thought to maintain the strength and integrity of the pack.  In lean times the pack is only as good as the weakest member.

Sometime around 15,000 years ago, some of these less aggressive wolves started to approach human to eat the scraps from their leftovers.

After wolves learned not to bite the hand that fed them, French poodles weren’t far behind. The wolves got food from us, and in turn they helped us in hunting, and some even ended up as food. 

People eat dogs

Though there was evidence to suggest that dogs genetically diverged from their wolf ancestors at least 15,000 years ago, some believed domestication has occurred earlier. Domesticated dogs first appeared in East Asia, probably China. They then spread across Asia and Europe, and then accompanied their two-legged companions into the Americas.



Today, some breeds are still dangerously aggressive because breeders retain their aggressive trait for our benefit; for guarding warehouses and crime fighting. Some are exceptionally gorgeous, a far cry from the shadow that once inhabited our nightmares.




Dogs are our companions, our friends and our helpers.  In most cases this partnership works out well.


info:
http://www.babble.com/CS/blogs/strollerderby/archive/2008/08/26/dog-rescues-baby.aspx
http://en.wikipedia.org/wiki/Dog
http://archaeology.about.com/od/domestications/qt/dogs.htm


When a tiger starts killing people, regardless of how endangered it may be, it has to be put down – at the minimum relocated to life in a zoo where it cannot harm humans. Similarly, if the extinction of a particular species could ensure the survival of mankind, hand me the shotgun please. That said, I cannot think of a single case of any organisms meeting this criteria except for some bacteria.

Of course, things have yet to go that far. We’re not facing some kind of apocalypse, and certainly not extermination by aliens so we can still work on sustainable development to achieve a win-win situation. But some people, and I seriously mean somepeople, emphasize the well-being of animals more than the well-bring of their own kind. And I’m not talking about the Japanese-hunting-whales-thingy. I’m against that, too.

Please stop whaling. Image: sustainablesushi.net

Some animal rights activists had recently pressured airlines and ferry companies against transporting animals to the UK for research purposes.

Lord Drayson, who was a minister in the last Labour government, said “extremists” had picked off the companies, which had pulled out of transporting laboratory mice and other animals. The Times reported that Stena Line had followed DFDS Seaways in halting the carriage of test animals, closing the last sea route for medical researchers. The Channel tunnel had long refused the trade, it said, while no UK-based airline, including British Airways, would carry laboratory animals.– http://www.guardian.co.uk

Image: sciencedaily.com

It’s understandable that these animal lovers treasure animal lives. But hey, medical research is important because we have yet to find a cure for AIDS, cancer, Alzheimer’s, and there are new diseases emerging every few years. Halting medical research could spell disaster because any new disease nowdays could potentially push the entire humanity towards extinction. Just think of it as a safety net to ensure the continuity of our species.

In the UNited States, and most other research heavy nations, there are extensive regulations in place to ensure research animals are humanely cared for.  The US alone has the governmental agency, the USDA, and groups like AALAS and AAALACi training and monitoring facilities that conduct research.

Sure, people get concerned about research on stolen pets, cute monkeys, cuddly bunnies and the like.  Fact is 98% of all research animals are rats and mice purpose bred for this purpose.  Keep in mind many of the people saying this should stop have multiple mouse traps in their own garage.  We are talking animals housed in very clean conditions, given full time care, veterinary support, food, water and n exchange allow scientists to research disease.  That is a far cry from Decon poisons in the garage for the wild population.

Laboratory mice reach sexual maturity by six weeks of age, and could produce up to 14 pups after a gestation period of 19~21 days. Mice infestation is a problem in many parts of the world so why worry about them? They are the most adaptable animal after humans, and most importantly they are the least of our concern when it comes to animal conservation.

Image: sciencedirect.com

The vast majority of research animals are the rodent family.  Dogs must come from documented breeders – most of whom are dedicated to the lab animal industry and are also inspected and heavily regulated.  No shelter pets here.  Many species of Non Human Primates are no longer used. 

In addition, many advanced in pet medicine have come out of this.  That vaccine you give Fido, or that pill you give your cat was made possible through other research animals and scientists.
Some research which focus on saving a particular species would inevitably require some individuals from the species itself to be tested, which is in itself a justifiable thing. But if people die from a disease whose cure is already at the brink of discovery, but made impossible just because some preposterous animal activists who couldn’t understand the importance of medical research and value the life of a pest more than that of a fellow human being decided to brand shipping companies as cold blooded accomplice, then humanity is doomed.

To come think of it, thousands of cancer patients, Alzheimer’s patients are waiting for medical breakthroughs all over the world, and yet the animal rights activists couldn’t understand the need to sacrifice a few rodents?

They should be charged with manslaughter. OK, that was in jest, but this is not undertaken lightly.  The people involved in this research are generally good and compassionate people.  Yes, there are a few whackos like any segment of humans, and unfortunately they get much bad publicity.  But 99.99% are loving and caring and intelligent people that deliver the best care they can to their charges.
Did you also know that there is a huge component of research that involves enrichment for animals?  We are talking toys, cool housing, nesting materials and treats.  I am not saying living as a research animal is a joy, it does ultimately end in a hopefully humane death.  But I can safely say 99% of research animals live more comfortably than 50% of household pets. There is no massive outreach to ban and stop people who lock their dogs in a room all day or a crate for 8 hours a day while at work.  Yet in the research side this is illegal unless they are exercised.

People have to stop being so squeamish about topics like food, research and biology.  Yes, its a complicated topic, but not that hard to understand and appreciate.

And to stave off those that might say I am a sadistic beater of animals I myself am a proud pet owner and go to great lengths for their care and comfort and that I’m against poaching, consumption of shark fin, and unplanned deforestation.