What makes dolphins and some kind of  whales help humans ?
397272
There are a lot of urban myths, this could be one. Still it is possible that a social animal like dolphins may try to help a human in distress. I suspect that they would easily detect our panic with their hearing. I doubt that it is totally instinctive since there is no apparent value to the dolphin. It could be play. Have you seen the footage of killer whales tossing seal cubs around as toys? Unfortunately there are records of dolphin pods fighting each other.
503201
actually, dolphins are the only other animal besides humans who enjoy sex. i was watching the discovery channel and these nasty dolphins were raping a baby orca whale. i cried
718005
Mainly their thick outer layer of blubber is able to absorb a lot of the pressure.  Their immense size does help even it out.  Unfortunately, even though they are built to be able to dive that deeply, it's not a harmless thing.  Whales do get the bends.  Often whale bones, especially those of sperm whales, show signs of nitrogen bubbles in the blood and tissues.  Over time it does cause them pain and in some rare cases some deformity.  So they're designed to be able to do it, but it is not risk-free to the whale.  There is a biological cost.
571640
Both dolphins and porpoises are mammals. Even though they both live in the ocean, they are not fish. They do not have breathing gills. They have lungs and breathe air. Both also give birth to live young and nurse those young. A mammal is also characterized by having the presence of hair: when dolphins and porpoises are small, there are small hair follicles. \n\nDolphins and porpoises belong to the same scientific order, Cetacea. This order includes all whales, even the great whales, to which both dolphins and porpoises are related. All cetaceans are completely aquatic mammals, have a streamlined body, a tail fluke, and a blowhole (which is what these air-breathing animals use to breathe). The dolphins and porpoises are also classified in the scientific suborder, Odontoceti, which are the toothed whales. All odontocetes also have the ability to echolocate, the ability to detect objects in their underwater environment using the echoes of a sound, much like sonar. \n\nPorpoises and dolphins are classified into two different families. The porpoises are in the family Phocoenidae and the dolphins are in the family Delphinidae. When separated at the family level, dolphins and porpoises are as physically different as cats and dogs.
341496
This will knock your socks off.  Whales and dolphins share a common ancestry with ... hippos!  (This is not a joke answer.)  Even Richard Dawkins was surprised by this ... "What is shocking is that, according to the molecular evidence, whales [and dolphins] are deeply embedded *within* the even-toed ungulates. Hippos are closer cousins to whales than hippos are to anything else including other even-toed ungulates such as pigs."\n\nIf nothing else, keep in mind that whales and dolphins are mammals, and thus evolved from land animals.  Based on genetic evidence, it seems that pigs and ruminants split about 60 million years ago (mya), and hippos split off from the ruminants about 55 mya.  The whales split off very soon afterwards at about 54 mya, with the semi-aquatic 'Pakicetus' appearing about 50 mya.  Toothed whales (including dolphins) and baleen whales split from each other about 34 mya.
103977
Whales evolved from terrestrial four-legged hoofed animals. They've acquired hydrodynamic fusiform bodies, including tail flukes (horizontal, in contrast to the tailfin of fishes, and without internal support), dorsal fins (more or less developed, or absent); their forelimbs are flippers and their hindlimbs are extremely reduced and within their trunks. They've lost all external structures that could offer resistance to the waterflow, such as external ears, hair, or external genitalia, and thus have a smooth body surface. This is important in order to keep a laminar flow of water around the body (turbulent water does not provide lift).\nIn addition to their hydrodynamic shape, they have a well-developed layer of fat (blubber) that provides both insulation and some buoyancy. They move basically by undulations of the caudal vertebral column that move the tail up and down.
498843
The products made from various bits of whale include:\n\n    * lamp oil (from sperm oil)\n    * margarine and cooking oil (from whale oil)\n    * candles, soaps, cosmetics and perfumes (from sperm oil)\n    * corsets and umbrellas (from whalebone)\n    * whale-meat for human consumption\n    * animal feed (from meat meal)\n    * fertiliser (from bone meal)\n    * string for tennis racquets (from tendons)
110511
There is.  Dolphins and monkeys are as intelligent as humans, just in a different way.  Dolphins have their own language that they communicate in and it has been proven that they are of equal intelligence as humans.  There are plenty of animals out there that are as intelligent as humans just in different ways.
374387
Dolphins would rule the sea.\nCockroaches the earth.\npigeons the sky.
205199
All species of dolphins use sound for echolocation. Using their melon (the bulbous portion of their forehead), they create a sound that bounces off objects around them. The returning echo of the sound gives the dolphin information about the location and physical description of the object. I don't know much about the actual workings of the brain though, but I do know that the dolphins sonar is much more advanced than human technology and can pin point exact information about it's surroundings ranging from size, distance and even the nature of the object. Dolphin Speech is so complex that the sounds even cross the species barriers and enable different kinds of dolphins to communicate.  They have been known to instruct each other as well as receive instructions and act accordingly.
294418
Sharks are fish and Dolphins are mammals. They have no scientific relationship, totally different species.
7374
I'm pretty sure that they do. However, if memory serves correctly, dolphins are the only animals that have sex for pleasure(other than humans).
437882
Most dolphins have acute eyesight both in and out of the water and their sense of hearing is superior to that of humans. Though they have a small ear opening on each side of their head it is believed hearing underwater is also if not exclusively done with the lower jaw which conducts the vibrations to the middle ear via a fat filled cavity in the lower jaw bone. Hearing is also used for echolocation which seems to be an ability all dolphins have. The dolphin's sense of touch is also well-developed.\n\nHowever, dolphins lack an olfactory nerve and thus have no sense of smell, but they can taste and do show preferences for certain kinds of fish. Since dolphins spend most of their time below the surface in the wild, just tasting the water could act in a manner analogous to a sense of smell.
100057
Dolphins represents knowledge.  And if you a colleting them, you have a strong desire to achieve knowledge!!!!  is that correct in your case!!!!???
359938
yes they are aroused, but not by the same things as us. Yes they have the same mechanical processes as we do for an orgasm.  Although I'm sure they don't have the emotional hangups that we do.  And dolphins aren't the only other animals that have sex for recreation.  There is a primate called the Bonobo that pretty much has sex all the time. Male-female, same sex, masturbation....whatever, they don't care.
187815
Whales communicate through what is known as whale song. These sounds are extremely loud and can be heard for miles. They have been known to generate about 20,000 acoustic watts of sound at 163 decibels. This sound is used by humpback whales and one species of blue whale.\n\nToothed whales such as orcas use high-frequency forms of clicks and whistles. It can act like a form of sonar.\n\nThey also communicate through signals breaching where they thrust themselves out of the water. As this costs the whale 1% of its energy, these signals are not taken lightly.
283592
They are part of the food chain for many species, whether it be at the beginning or in the middle. If dolphins disappeared, certain species would become over populated, and others would die off.