Researchers have captured a Dolphin with fully developed rear fins, which supports fossil evidence that Dolphins were once land-based creatures similar to dogs. More concrete evidence of Evolution. http://www.dailymail.co.uk/pages/live/articles/news/news.html?in_article_id=414678&in_page_id=1770 As they leap over the waves and perform their extraordinary acrobatic feats, dolphins are the embodiment of water-borne grace. Yet, almost incredibly, this was not always their element. Experts believe that the dolphin's ancestor was a dog-like creature which roamed the earth many millions of years ago. And now the extraordinary discovery of a bottlenosed dolphin with an extra set of flippers has provided living proof of the theory. At first glance it looks like any other of its kind. But closer inspection reveals a rogue set of rear fins. Each the size of a human hand, the fins are thought to be the remains of a pair of hind legs, adding to evidence that dolphins once walked on all fours. While dolphins with odd-shaped lumps jutting out near the tail have been caught before, this five-year-old bottlenose is thought to the first with a full second set of fins. Scientists have so far been unable to tell whether the four-finned dolphin, caught in fishermen's nets off Japan's Wakayama province a week ago, uses its extra set of fins when swimming. The creature, 9ft from nose to tail, is now in a tank at a whaling museum where it will undergo both X-ray and DNA testing. Seiji Osumi, of the Institute of Cetacean Research in Tokyo, said: "I believe the fins may be remains from the time when the dolphin's ancestors lived on land. This is an unprecedented discovery." Recent fossil finds support the belief that, 50million years ago, forerunners of the present deep-sea mammals had limbs and were quick on their feet. The creatures, which belonged to a group called Pakicetids, looked like a cross between a wolf and a tapir and had large heads, long powerful tails, spindly legs and ankle bones well adapted for running. They also had bones in their ears which are unique to cetaceans, the sea family to which whales and dolphins belong. It is thought the dolphin's land-loving ancestors first crawled into the sea to escape predators or seek food between 50million and 35million years ago. Their hind legs became smaller and smaller before eventually disappearing altogether. The new aerodynamic shape reduced drag in the water, speeding their swimming. Mark Simmonds, of the Whale and Dolphin Conservation Society, said: "They became more and more streamlined, lost their hair and developed a layer of fat for insulation." Evidence of the long-lost rear legs can still be seen in the dolphin foetus, which contains leg 'buds' which disappear before birth. Now, it seems a freak mutation, perhaps caused by pollution of the oceans, has caused the long-lost trait to reassert itself in a modern-day dolphin. Further evidence of the dolphin's past as a land-dweller comes from its inability to breathe under water, and the bones of its fins, which are very similarly jointed those in the human hand.
Pretty interesting find. I'm mainly impressed that the Japs didn't just eat the extra feet and consider it a bonus. :hihi: I'm sure the anti-evolution crowd will just say that's the way that one dolphin was created 8,000 years ago. :rofl:
This is interesting, but I don't see how this is "proof" of anything. I grew up on a farm, and saw a calf born with an extra head. Does that mean cows evolved from a two headed creature? Or does it mean they are evolving into a two headed creature? It may just be an example of in breeding. Kinda like people from Arkansas.
Yes, but if you saw the part about many other dolphins found in the past with undeveloped nubs in that spot, it goes to show that it is not just a one-time mutant thing.
I'm not asying it's a one time mutant thing. The point I was trying to get across was that just because this has somewhat re-occured, doesn't mean it isn't anything more than a genetic flaw. I don't think there will ever be definitive "proof" either for or against evolution. To call this proof IMO is a stretch, many creatures are born with some type of disfigurement, example children born with a cleft lip.
True enough. The dolphin could be a mutant. Of course mutations are part of what drives evolutionary change. If those extra fins inhibit the dolphin, it will die young, probably without offspring. If those extra fins give the dolphin greater control and allow it to outperform other dolphins, then it will live long and pass its genes on to other generations of dolphins and more extra fins will appear on dolphins in that strain and could eventually become a new species. All one need to do to see living proof of evolution is to look at your dog. Fossil evidence suggests and DNA analysis proves that all breeds of domestic dogs evolved from the wolf in the last 10,000 years. All you have to do is look at a Great Dane and a Chihuahua to realize that not only is evolution real, but it is working right now, . . . just as it always has.
Lt me re-phrase my post to clarify it a little bit more. I don't think this proves one way or another that Dolphins evolved from a 4-legged land based creature. This isn't a subject I'm well educated on, so I'm not going to debate whether or not Dolphins did indeed evolvef rom that, but to say a dolphin with extra fins proves that they did is quite a stretch. People and animals are born with something "wrong" or "different" about them on a regular basis, yet no-one say that it proves they evolved from whatever disfigurement is taking place. But since in this case they want it to mean that, they call it proof. I just disagree with that point of view.
