did dolphins really evolve from land animals?
447053
yes, and so did whales and seals etc
397202
What is the difference between a dolphin and a porpoise? I heard this question asked, on Johnny Carson. And, Johnny decided that a dolphin was a mammal, and a porpoise was a fish. Wrong. They are both mammals, and are very closely related. The porpoises have a rounded head, while the dolphins have a protruding snout. They are smaller members of the toothed whale family, to which killer whales and sperm whales belong.\n\nTo complicate things, there are a couple of fish which are also called dolphins. I assume that these are sometimes called "dolphin fish" to avoid confusion. But, the well-known dolphins are those cute mammals, like Flipper (who is a bottle-nosed dolphin).\n\nMammals have hair, breath air, give birth to live babies (platypuses and echidnas lay eggs), and feed milk to their young. Whales breath air (they can hold their breaths for long times), give birth to live babies, and feed milk to their young. Where is their hair? Evidently, they have a small amount of hair around their blow-holes, those holes, in the top of their heads, that they breath through.\n\nThe toothed whales are among the most intelligent of all animals. The killer whale (orca) apparently has a brain mass to body mass ratio (a rough measure of intelligence) which is greater than that of humans. Incidentally, while toothed whales are predators, there is no record of any killer whale ever having killed a human being.
542279
No, there are fairly major differences in their fine skeletal anatomy, especially their teeth that indicate that cats and lemurs evolved from completely different lineages of early mammals.\n\nThe primates (such as the lemurs) evolved from an insectivore lineage, and the earliest primates back in the Cretaceous would have looked rather similar to the modern tree shrew (Order Scandentia).\n\nThe carnivores evolved from condylarth stock (which also gave rise to the ungulates and the whales eventually), through early predators like Cimolestes, the cohort Ferae and from earlier Carnivores very similar to the Viverrids.  Modern civets and genets are probably most like the very early cats.
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.
173408
Yes, or at least from some predatory archosaurs. There are currently two strong theories, each with their supporters: birds are dinosaurs (Padian, Chiappe, etc.), or birds are non-dinosaur archosaurs (Feduccia).\n\nIf they evolved within the Dinosauria, as much evidence seems to show (see link), then according to a cladistic classification they ARE dinosaurs (the same way that we are Sarcopterygians, even if we're not fish-like anymore).
788917
Have a look at the limbs of a lizard.  Not too unlike ours - has all the same sections in the same places.  Some even have five "fingers".  \n\nWhen mammals came along they took the format much further - creating ungulates with two toes, horses with one, dogs with four and a dew claw.  \n\nEven whales have the skeletal bones of hands in their pectoral fins.  \n\nLemurs are supposedly more primitive than monkeys and apes, but go see them at a zoo.  I was lucky enough to hand feed one, and it has hands remarkably like a tiny human.  It was unreal.  \n\nThe format has changed constantly, built on a vertibrate format developed initially by fish.
525455
If snakes evolved from land dwelling creatures, then those land dwelling creatures evolved from sea creatures.  After all, humans evolved on land.
501937
No, but some theories must confirm it now. The best theory is that there are water on Mars long ago. That may prov that there is life on mars. The problem is, it's not proven yet, and other theories are here.\n\nBut remember, every life in a planet starts with water, so maybe, bacteria evolved into sea animals because of water, then to reptiles, to animals, monkeys, and so on.
270627
Penguins, like other flightless birds (ostriches and emus) evolved from birds that could fly.\n\n65 million years ago the ancestors of today's penguins flew over the ocean and dove down into the water for food.\n\nOver millions of years, their hollow bones became solid and they could no longer lift themselves out of the water to fly. But, their heavier bones made is easier for them to dive down into the water.
1012778
We didn't evovle from monkeys we evolved from a monkey-like creature which evovled from something else all the way back to cells before that amino acids which form naturally in space.\n\nThis took billions of years and millions for humans to evolve all the time God was there too.
937655
All the claims based on human physiology have good non-aquatic possibilities such as adaptations to a savanna lifestyle, so it's not a compelling theory.\n\nIt does however seem entirely plausible that as generalists, our ancestors may have foraged around the water's edges and shallows, much like some monkeys do today.\n\nThere's a good list of the arguments for and objections (at the bottom) against the theory on Wikipedia at the link below
954976
I bet some dolphin told you that, right?\n\nYeah, I though so. So while we're busy attacking them, the dolphins consolidate their grip on the oceans
559225
Much of the support for the idea that snakes evolved at sea is their close phylogenetic relationship with the extinct group of marine reptiles, the mosasaurs.\n\nBoth snakes and mosasaurs share a number of unique characters, such as a hinge in the middle of the lower jaw, loss of the symphysis joining the two halves of the lower jaw, and the stabilization of the spinal column (the zygosphene-zygantra articulation).  These adaptations seem to have been a major evolutionary success, and led to adaptive radiations of the mosasaurs, snakes and the aigialosaurs (another extinct related group).\n\nIf the group (often called the Pythonomorpha) evolved at sea, it would explain a lot of the other adaptations (such as reduced or modified limbs) that these groups show.  However, more and more the fossil evidence seems to indicate that the Pythonomorpha probably evolved on land, and then each group developed adaptations ideal for marine environments totally separately.\n\nThis solution is not as elegant as it would be if all of the adaptations in the Pythonomorpha occurred at the same time, but it appears that sometimes evolution does not occur as elegantly as we might like.\n\nA terrestrial origin for snakes does explain some of the other unusual features of snakes, such as their eyes which show signs of having been reduced or completely lost at one point, and then an entirely new visual anatomy developed as they re-emerged from a subterrainean existence.
193198
While it might be possible that some of these creatures exist, it certainly can't be said to be 'probable'.\n\nWe are still finding new species of mammals and birds all the time.  Genetic studies have even shown us that some of the critters we thought we knew are more diverse than we thought.\n\nRecently it was discovered that the species we know as the African elephant is in fact two species, a savannah species and a forest species.  So we have 'found' one of the largest species of land mammal just in the last few years.  Another study found that there was a population of the Bactrian camel (the one with two humps) that was actually a separate species too.\n\nSo it is possible that there may be some critter hidden off in the deep forest somewhere that we've never seen before.  But the chances of something like Bigfoot/Sasquatch remaining undiscovered in the rather well explored forests of North America are rather low.\n\nThe best chance for new, exciting and incredible discoveries are in the seas.  We really have barely scratched the surface in our exploration there, and there could be all kinds of new, even huge and exciting finds down there.\n\nJust in the last few years, the Megasquid was described, whose body is larger than that of the Giant Squid (although the tentacles aren't as long), actual live footage of the Giant Squid was finally taken, and Coelacanths were found off the coast of Indonesia, 10 000 km from where it was thought was the only place they existed.
490342
No.  Sharks (and Dolphins which are actually faster than most sharks) are perfectly adapted for travel in water making them the fastest and deadliest (for fish, anyway) creatures in the sea.\n\nHumans, even with wet suits and flippers, will never approach the speed (or agility) of practically any fish or sea mammal except maybe a sea horse, unless they are strapped to some self propelled machine.  \n\nShark and Dolphin bodies are streamlined to slice through water and practically all the muscles in their huge bodies are devoted just for swimming (except maybe their jaws).  We just aren't streamlined enough and our muscles aren't designed to be powerful enough to push our awkward bodies through water.
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.
106270
Yes, if you know how to speak in thier "language". Dolphins are alot smarter than we are. You can 'speak" to any animal if you know how to "listen" to them. You"listen" by watching thier actions, facial expressions, body language, and by listening to the different sounds they make.