How Sharks Hide Their Fingers

livescienc e ^ | 07 February 2006 | By Ker Than, LiveScience Staff Writer

[Flavius]

The genetic potential to create fingers and toes apparently existed ages before animals even crawled onto land, dating back to the distant common ancestors of sharks and humans, research now reveals. ADVERTISEMENT

The research focused on a group of genes that control how and where body parts develop in animals, including people. Scientists investigated the activity of these "Hox genes" in embryos of the spotted catshark.

Unexpectedly, they discovered that a spurt of genetic activity that helps digits such as fingers and toes develop in limbed animals was seen in shark embryos as well.

"Genetic processes were not simple in early aquatic vertebrates only to become more complex as the animals adapted to terrestrial living. They were complex from the outset," said developmental biologist Martin Cohn at the University of Florida at Gainesville.

So why don't sharks have fingers?

Although the genetic program needed to create digits might exist in sharks and many other kinds of fish, they only activate it briefly, said University of Florida graduate students Renata Freitas and Guangjun Zhang. In other words, people and other limbed vertebrates use this ancient recipe from their genetic cookbook and extend the cooking time.

[SandRat]

WOW! Proof of what Lawyers Evolved from!

[JennysCool]

By Ker Than

One of the top science writers in the bottle city of Kandor. :-)

[Hot Tabasco]

So why don't sharks have fingers?

Because they don't wear shoes with shoelaces that need to be tied?

[Triggerhippie]

I’ve never seen shark fingers, but I’ll bet they’re every bit as tasty as chicken fingers.

[GBA]

I think cats evolved from sharks.

[ichabod1]

Sometimes they remind me of snakes... and I have two.

[Grizzled Bear]

...and I have two.

---

Sharks, Snakes or Cats?

[JCEccles]

The genetic potential to create fingers and toes apparently existed ages before animals even crawled onto land.

Absolutely impossible. Darwinism's current high priest Dawkins has assured us that there is no such thing of "front loading." Fingers evolve and develop blindly, incrementally, in response to completely random evolutionary pressures and natural selection. Evolution does not anticipate anything. End of debate.

That's the unchallengeable Darwinist faith claim, and anyone who disagrees runs the sure risk of being shunned, denied tenure, and maybe even being sued.

[ricks_place]

Shark Fingers

one fresh shark

1 lb shark fillet, strips 1/2
1 beer, flat, can
2 cup flour, self rising
1 cup corn meal
1 1/2 cup milk
2 tablespoon condensed milk
1/4 teaspoon basil
1 teaspoon salt
1 teaspoon pepper, black
2 tablespoon prepared mustard
1 peanut oil

Soak shark strips in flat beer for one hour. In a bowl, mix flour, basil, corn meal, salt and pepper. In another bowl, mix thoroughly milk, condensed milk and prepared mustard. Combine contents of both bowls and blend to smooth batter. Preheet deep fryer to 350-400 deg. Remove shark and drain. Dip in batter, then place in deep hot peanut oil. When fish is done, it will float and turn a golden brown color. Serve with tartar sauce or thousand island dressing.

Source: LOUISIANA CONSERVATIONIST Sep/Oct 81 Recipe date: 08/21/81

[Octar]

1 beer, flat, can

I got the flat beer can, but there's nothing in it.

snort

[freekitty]

giggle

[caveat emptor]

Soak shark strips in flat beer for one hour

That sounds familiar. We once tried eating dogfish, a kind of small shark, very common in the waters where we fished, but inedible because of the foul taste of their flesh. That was because "Since sharks have no urinary tract and urine accumulates in the blood before secretion through their skin, sharks must be bled immediately after capture. If a shark is not bled or improperly handled, it will smell of ammonia."

We heard that they could be made edible by first marinading in some concoction, possibly containing beer, but it didn't work. Supposedly they were widely used in Britain for "fish and chips".

[null and void]

I’ve suspected for decades that sharks returned to the sea, like porpoise, whales, and ichthosaurs.

The eyelids are one indicator. The absence of a swim bladder is another...

[mikrofon]

I take it they’re not referring to the “Finger of Friendship” here...

[dr_lew]

“genetic potential” is a loaded term here. “Hox” is short for “Homeobox”, and is a genetic sequence that is part of the machinery for gene expression, rather than a gene for a particular feature.

These were discovered in fruit fly research as the “hedgehog gene”, since a mutation in the gene produced a bristly fly. A homologous gene was found in mammals, and was called “sonic hedgehog”. This term actually appeared in journals, but was soon dropped.

So, the Hox gene is very general purpose, and without knowing what the particulars are of this shark/human homology, bear in mind that the basic function is common even to vertebrates and invertebrates.

[null and void]

Still, it’s simply amazing that a shark would even have the genetic potential to have fingers, isn’t it?

(Note that referring to the phalanges as “fingers” is linguistically loaded. Lower animals don’t have fingers, only toes)...

[dr_lew]

You can look at it the opposite way. If land animals evolved from fish, the "genetic potential", that is, a genetic encoding of a body plan capable of evolving this way, must have existed in fish. Sharks are primitive fish, and not direct ancestors of land animals, so the remarkable thing is that this potential to have fingers should have existed so much earlier.

But fingers and toes are just one more expression of the general plan that produces a wide variety of bodies. Note the careful wording of the article:

Unexpectedly, they discovered that a spurt of genetic activity that helps digits such as fingers and toes develop in limbed animals was seen in shark embryos as well.

This is a homology of the developmental process, not a homology of structure.

[wildbill]

A shark that could grab you in its fingers and bite off your head at leisure might be scary.

[Lonesome in Massachussets]

Oh the shark has pretty teeth, dear
And he shows them pearly white
Just a jack knife has MacHeath, dear
And he keeps it out of sight

When the shark bites with his teeth, dear
Scarlet billows start to spread
Fancy gloves though wears MacHeath, dear
So there’s not a trace of red

On the sidewalk, Sunday morning
Lies a body oozing life
Someone’s sneaking round the corner
Is the someone Mack the knife?

From a tug boat by the river
A cement bag’s dropping down
The cement’s just for the weight, dear
Bet you Mack is back in town

Louie Miller disappeared, dear
After drawing out his cash
And MacHeath spends like a sailor
Did our boy do something rash?

Sukey Tawdry, Jenny Diver
Polly Peachum, Lucy Brown
Oh the line forms on the right, dear
Now that Mack is back in town