Why were sharks brought to earth?
353721
ERRRRRR evolution!!! 2 points
168961
They may have been on loan from another zoo/aquarium. Zoos will loan animals out for different types of reasons. The Columbus Zoo once had an exhibit for Panadas, but they didn't stay as a permanent feature. It was just a stop on the Panda's travel list. Animals are also loaned for animal husbandry.\n\nCedar Point in Ohio used to have an exhibit with dolphins, but they no longer do. The dolphins were probably sold to another sea establishment. Marine mammals tend to be moved around a lot from aquarium to aquarium.
114432
Ok, I know that the bit about sharks not breathing if they're still is still taught at school, and essentially it has some point. It's true that gill oxygenation is better when the water flow through the branchial area is greater. \nBut sharks DO indeed stop swimming, they can rest near the bottom of the ocean (as if sleeping) and they use the pumping motion of the floor of their mouth (their mostly immobile tongue) to help water move through the gills. \nBut as I've said, immobile sharks lie mostly near the ocean floor. This is because they're rather dense with respect to water (they don't have swimming bladders like bony fishes do), although their enormous, fat-filled liver increases their buoyancy significantly (along with other physiological characteristics). When they swim, sharks can keep themselves in midwater; the movements of the trunk and tail generate the necessary thrust to keep them from falling to the bottom.
389285
no-we humans would then build large floating continents to live on- and yes ive seen water world- but i dont think thats possible- it would take millions of years for such an evolution to occur and in the movie the other humans are still the same- for this to happen the costner characters early ancestors should ahev spent their whole lifetime in water(while they still dint have gills)- and i dont see how they could have survived like that.
453004
Was it a real shark or a fake prop like the stuff they found where they had held Claire to steal her baby... Hummm, maybe it's to keep them scared and keep them from trying to escape again...
471078
There are sharks in all seas and oceans aaround the world. \n\nThere are many species of sharks found in the Mediterranean, especially in the western and central Med - including Hammerheads and Great Whites. Unfortunately the numbers of these sharks, of all sharks in the med, are in great decline and in many areas the numbers are close to non-existent. The culprit for this is commercial fishing (for blackfinn tuna and swordfish - both as a result of being caught in netsAND having their natural food sources depleted, in some cases to extinction - bluefin tuna became extinct in the Med in the 1940's)and, ironically enough, tourism. Especilly around Croatia in the late 90's there were several 'Jaws Tours'operating. The 'chumming' undertaken to attract sharks obviously attracted sharks into tourist areas which resulted in the culling of many, many sharks so as not to endanger tourism!\n\nSo, yes, there are sharks in the Med but I wouldn't be put of swimming in the Med as shark attacks here are almost non existent. Between 1508 and 2004 therewere a total of 38 shark attacks in European/Mediterranean waters. 18 of which were fatal with the last reported fatal shark attack being in 1984.  \n\nBut please get your friend to put the possibility of shark attack into persective. WORLDWIDE shark attacks between 1508 and 2004 totalled 1,986 of which 486 were fatal - in almost 500 YEARS! More people have been killed by deers running into their cars than by sharks!
9530
Sharks have sharp teeth because to kill animals/preys quickly and to avoid the preys from escaping with little injuries.\n\nIf the teeth were not sharp, how would sharks kill \npreys if the preys are virtually unhurt bacause of blunt teeth?\n\nAlso, God made the teeth sharp so that the killing will be quick and less painful.\n\nSharp teeth made sharks hydrodynamically superquick. Teeth covering their bodies make that happen.\n\nWith very sharp teeth, sharks do not have to exert big bite force to kill preys.
258814
since we all evolved form one celled organisms, which started in water, then we do come from fish. the "land egg" got us out of the water.
432907
Is there a reason you're asking this question under a new name?  Did you not like the previous answers?\n\nMy answer from: \n\nhttp://answers.yahoo.com/question/index;_ylt=Aosgux8O5O_.4Y0ThAeGgyjsy6IX?qid=1006041806251\n\nSome sharks are very slow and the average person can easily outswim them, at least for the short term. Sharks probably have better stamina and would eventually catch up.\n\nRemember, sharks are a very diverse group. There are huge, filter-feeding whale sharks and tiny little miniature dogfish. Everything from the weird cookie-cutter sharks to the weirder goblin shark.\n\nGuitarfish are especially slow sharks, if I remember correctly.\n\nYour real question is, Will someone ever be born who can outswim the *fastest* shark. The answer is probably no. We are not well designed for life in the water and our swimming is extremely clumsy. Evolution has no reason to fix any of these problems given we are resolutely terrestrial.
90693
At the moment, they are in balance.  The salt in the ocean came from minerals and rocks dissolved over millions of years. To markedly increase salinity in the world's ocean, a substantial quantity of water would have to be lost. In general, our planet biosphere has a set quantity of water. It is either tied up in oceans, living creatures, clouds/vapor, ice or the freshwater sources in wells, rivers, etc. What evaporates from the sea is ultimately returned via rivers, runoff, etc. The melting icecaps is actually a SUBSTANTIAL contributer to the total volume of the seas. However, as sea levels rise, so does rthe capacity to absorb more minerals, so the salinity would fluctuate over a few thousand years and stabilize about where it is now.
517070
Odly enough sharks will eat just about anything. The quetion now is what can you "bait" them with. I believe and form of chum (chopped up fish parts still in the blood) is a good start. Then I believe large chunks of relatively fresh fish or seal decoys.\nCheck out National Geographic's Web page on Sharks.\n\n-Stretch
862981
Seals evolved from some terrestrial animal because anatomical analysis shows a 5-digit fin.  It probably evolved from a bear or otter-like creature.   Many mammals spend the majority of their time in the ocean, and when feeding is more successful in the ocean than on land, aquatic adaptations derive.
582111
Why do u want to catch a sand shark???
574612
Th Great White Shark migrates to warmer waters each fall (autumn) and back again in the spring.\n\nAccording to the Bronx Zoo-based Wildlife Conservation Society, one female great white shark tagged in waters off South Africa completed the first known transoceanic trip for an individual shark, traveling farther than any other shark known, more than 12,400 miles (more than 20,000 kilometers) to the coast of Australia and back again. The shark was named Nicole (for Nicole Kidman, a well-known shark lover). Awwwwww!
616561
The scales- Same structure, shape, and composition- In fact, a related function, since sharks will brush the sides of their body by interesting possible food items to scrape off a little (of your skin, for example) in order to "taste" it with special sensors in the skin.  Generally, if a shark does this with a human, they will *not* attack further.
397671
They bash into their predators. they are actually quite strong. they kill sharks that way
542071
It is indeed a myth that sharks cannot get cancer, but their rather "simple" immune system works surprisingly well (think for example that sharks during mating bite - usually the male bites the female - leaving the partner with deep lacerations of up to two inches and five or six inches long, which after about two months have healed without any scarring).  One of the reasons we thought elasmobranchs (sharks, skates and rays) cannot get cancer was that we had never seen one that had.  But since then, sharks with tumors have been found and another myth was debunked.\n\nNow, in experiments elasmobranchs have shown tremendous resistence to toxins that would be highly cancerogenic in humans.  In the late 80s, Carl Luer of the Mote Marine Labs tested aflatoxin B1 on nurse sharks and found that they metabolized it differently from us (it is actually the metabolite we produce that gives us cancer).  In other words, a number of pro-cancerous substances in humans are not necessarily affecting elasmobranchs.