Dolphin found with possible vestigal leg mutation

[Ian David]

Dolphin May Have 'Remains' of Legs
Researchers Say Dolphin Has 'Remains' of Legs, Possible Evidence Ocean Mammals Lived on Land

By HIROKO TABUCHI

TOKYO Nov 5, 2006 (AP)— Japanese researchers said Sunday that a bottlenose dolphin captured last month has an extra set of fins that could be the remains of hind legs, a discovery that may provide further evidence that ocean-dwelling mammals once lived on land.

Fishermen captured the four-finned dolphin alive off the coast of Wakayama prefecture (state) in western Japan on Oct. 28, and alerted the nearby Taiji Whaling Museum, according to museum director Katsuki Hayashi.

Fossil remains show dolphins and whales were four-footed land animals about 50 million years ago and share the same common ancestor as hippos and deer. Scientists believe they later transitioned to an aquatic lifestyle and their hind limbs disappeared.

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The second set of fins much smaller than the dolphin's front fins are about the size of human hands and protrude from near the tail on the dolphin's underside. The dolphin measures 8.92 feet and is about five years old, according to the museum.

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A freak mutation may have caused the ancient trait to reassert itself, Osumi said. The dolphin will be kept at the Taiji museum to undergo X-ray and DNA tests, according to Hayashi.

More:
http://abcnews.go.com/Technology/wireStory?id=2629683


In this photo released by Taiji Whale Museum, divers hold a bottlenose dolphin which has an extra set of human palm-sized fins near its tail in Taiji, Wakayama prefecture (state) in western Japan, on Saturday November 4, 2006. Japanese researchers said Sunday that the could be the remains of back legs, providing further evidence that ocean-dwelling mammals once lived on land. (AP Photo/Taiji Whale Museum)

On edit

I had always thought that the Dolphin's tail was itself hind legs that had fused together over the eons into a big fin. Could it be that the Dolphin's tail is actually an adapted land-mammal tail, and not two back legs fused into a tail?

[nosferaustin]

1. Maybe they're getting ready

to start all over again once we humans destroy ourselves with out stupid, stupid ways...

[Donkeykick]

3. No.

Its those mean ole Democrats experimenting with cloning.:sarcasm: :eyes: :rofl:

[Ian David]

9. Maw and Paw good! n/t

[LaBanty]

2. No! It's Bad Science!

Everyone knows there's no such thing as evolution... or global warming!

/channeling a Fundie

[pansypoo53219]

4. but but but

this would be devolution. if they were 'fish' to start, went onto land and then BACK to water.
pfft. i don't care. let's fix the crap we have NOW. who CARES how we got 'here'.

no, i do not BELIEVE in eveolution.

[Ian David]

7. Evolution is a misnomer. There is no implied "direction" to Natural Selection

It was the Communists who tainted the understanding of Natural Selection by insisting that species-- and therefore governments-- progressed toward greater perfection over time.

Species are selected for greater fitness for their environment.

[YankeyMCC]

5. They're growing legs so they can

come back up on land and kick the humans in the ass for fracking up their oceans.

[AlienGirl]

6. The cetacean tail is indeed an adapted genuine mammal tail!

Many cetaceans still have vestigial pelvis bones around the same place on the body where this one's bonus flippers are. That doesn't necessarily means this dolphin has a set of switched-on genes for forming back limbs, though; all dolphin embryos have hind-leg buds early on (just like all human embryos have tails at one point) and it could be that something in the uterine environment prevented the cell-death that is normal in the hind-limb buds later on. (The analogy for this would be humans born with a vestigial tail, or with webbed fingers or toes, where what went askew was more about local cell-death and cell division rates and not necessarily a mutation in all of the individual's DNA.)

Dolphins have horizontal tail fins, instead of vertical ones like fish, because mammals evolved a spine that flexes up and down better than side-to-side. It was easier to adapt the up-and-down flexion of quadrupedal running to up-and-down flexion for swimming and adapt a tail than it would have been to try to re-evolve the side-to-side flexibility that fish and salamanders have.

Tucker

[DLake]

8. Wow...

...I never thought that after years of lurking, this would be my first post. But I cannot remain silent; this is too important:

Dolphins Evolve Opposable Thumbs

It's happening!!!