Surprise: Chickens Can Grow Teeth

Live Science ^ | 22 February 2006 | Bjorn Carey

[GreenFreeper]

Chicken will grow teeth when pigs can fly.

Well, better start searching the skies for flying pork—scientists have discovered a mutant chicken with a full set of crocodile-like chompers.

The mutant chick, called Talpid, also had severe limb defects and died before hatching. It was discovered 50 years ago, but no one had ever examined its mouth until now.

The researchers recently created more Talpids by tweaking the genes of normal chickens to grow teeth.

"What we discovered were teeth similar to those of crocodiles—not surprising as birds are the closest living relatives of the reptile," said Mark Ferguson of the University of Manchester.

What happened

Around 300 million years ago, the ancestor of all modern vertebrates gave rise to two lineages, the mammals and the reptiles/birds. The oldest reptiles, such as crocodiles and alligators, had cone-shaped teeth. So did the earliest birds, called archosaurs.

Then, around 80 million years ago, modern birds emerged without teeth.

"So what would you expect bird teeth to look like? You would expect them to have teeth like their ancestors and their most closely related living relative," study co-author John Fallon of the University of Wisconsin told LiveScience.

Indeed, Talpid's teeth are conical, much like an archosaur's and closely resembling the teeth of a baby alligator or crocodile, Fallon said. If the chick survived, the teeth would most likely reabsorb into the mouth.

The archosaurs had mouths similar in shape to a reptile's. It turns out that developing a beak caused birds to lose their teeth.

"The reason that birds lost their teeth is that in forming a beak, the two tissues that ‘talk' to each other to make a tooth become separated," Fallon said. "They can't have the conversation to make a tooth. In the mutant, these tissues are brought back together."

Make more mutants

The finding made scientists curious whether healthy chickens still possessed the 80-million-year-old genetic pathway for producing teeth.

By making a few changes to the expression of certain molecules in the pathway, the researchers were able to induce tooth growth in normal developing chickens. These teeth also looked like reptilian teeth and shared many of the same genetic traits, supporting the scientists' hypothesis. None of these chickens were allowed to hatch.

This is all good news for hockey players. A direct application of this research, Ferguson said, could be re-growing teeth in people who have lost them through accident or disease.

The research is detailed this week in the journal Current Biology

[wideminded]

This is not a complete surprise in that it was already announced 8-10 years ago that turning on certain dormant genes in chicken embryos could cause teeth to form inside an egg.

[PeterPrinciple]

"I do not know for certain how they developed but I know several herbivorous dinosaurs were thought to have rudimentary gizzards. The evolution of a gizzard eliminated the need for sharp teeth and thus were lost. Birds are thought to be descended from herb. dinos so this makes quite a bit of sense to me."

As long as they had sharp teeth, there was no need for the gizzard. So the animals decided to eat stones to dull their teeth so they could eat plants? Doesnt't maake sense to me, might to you.

Back to the old question, WHAT CAME FIRST, THE CHICKEN OR THE EGG.

Evolution sounds a lot like the "invisible hand" in the Wealth of Nations by Adam Smith.

[DannyTN]

That birds carry the genetic potential for teeth does not imply that they evolved from reptiles or any other creature except other birds that may or may not have had teeth.

In fact the article demonstrates that rather than a mutation occurring that suddenly tells chickens how to grow teeth, the genetic potential for teeth has been there all along and can be stimulated just by introducing the right chemical signals.

All this shows is that most creatures have more built in adaptability and variation in their genetic potential than we would normally assume.

[Marine_Uncle]

"By making a few changes to the expression of certain molecules in the pathway, the researchers were able to induce tooth growth in normal developing chickens."
What appears to continue to be elusive to the evolutionist is the fact that mutations lead to pre-mature death, or to abnormalities that lessen the particular species functionality as set forth in it's particular genetic structure, and it's associated biochemical functionality.
If by chance some bird species had mutated way back when and successfully produced a new strain at the far limits of its normal range of characteristics, and the particular morphological change was benificial. Why do not many species within the family of birds have teeth at this point.
I just cannot buy this stuff. These people have one mind set and will, to fit their agenda/believe system, go to any extreme to accomodate their supposed theories and findings.
With humility in mind. I see little difference in this particular case and say Stanley Miller and his coharts attempting various early earth experiments to create amino acids complexes from basic raw materials in a laboratory controlled set of conditions, required cold traps etc. to extract amino acids from the mixtures after their exposure to high voltage discharges and or ultra-violet bombardment. The end result being a bucket of goo if each carefully monitored step in the control process was not carried out.
They live in a dream world.

[GreenFreeper]

That birds carry the genetic potential for teeth does not imply that they evolved from reptiles or any other creature except other birds that may or may not have had teeth.

Never implied this. The question dealt with the evolution of the gizzard, fairly unrelated to the article.

All this shows is that most creatures have more built in adaptability and variation in their genetic potential than we would normally assume.

Exactly. Homeotic genes and heterochrony give further credence to this idea.

[GreenFreeper]

Why do not many species within the family of birds have teeth at this point.

Well as the article stated, the chicken with the teeth did not survive, therefore, it could not have passed on those genes. While the death may or may not have been the result of having teeth, one must survive and reproduce for evolution to occur. Additionally, having teeth must have a distinct advantage if it is to be incorporated into the population. Often a perceived advantage can be a disadvantage. Teeth can be very costly- from the energy expended in production, to upkeep, to fighting off infections.

The same reason we don't have large claws is likely the same reason chickens don't have teeth- they and we don't need them. It does not provide any significant advantage.

[Marine_Uncle]

Reasonable response.

[swmobuffalo]

Better chicken with teeth than Cows With Guns!

[DannyTN]

"Never implied this. The question dealt with the evolution of the gizzard, fairly unrelated to the article."

I wasn't responding to the gizzard discussion, I was responding to the article itself your post #1. And the article implies evolution with references to reptiles, "80 million year old genetic pathway" and the assumption that development of a beak caused the lost of teeth.

My point, which I think you understood, was that creatures were created with a lot of genetic potential. Thus Adam may have carried the genetic potential for pygmies to Amazons, and all the colors of the rainbow without the need for mutations or evolution to account for diversity.

[theFIRMbss]

>Chickens are turning into alligators ... is that the thesis here?

Maybe this provides
a long needed clue into
famous old lyrics --

------------------------------------------------------------------

Chewing on a piece of grass
Walking down the road
Tell me, how long you gonna stay here, Joe?
Some people say this town don’t look good in snow
You don’t care, I know

Ventura highway in the sunshine
Where the days are longer
The nights are stronger than moonshine
You’re gonna go I know

’Cause the free wind is blowin’ through your hair
And the days surround your daylight there
Seasons crying no despair
Alligator lizards in the air
In the air...

Wishin’ on a falling star
Waitin’ for the early train
Sorry boy, but I’ve been hit by purple rain
Aw, come on, Joe, you can always
Change your name
Thanks a lot, son, just the same

Ventura highway in the sunshine
Where the days are longer
The nights are stronger than moonshine
You’re gonna go I know

’Cause the free wind is blowin’ through your hair
And the days surround your daylight there
Seasons crying no despair
Alligator lizards in the air
In the air...

Do, do-do
Do, do-do
Do, do-do
Do, do-do ...

[theFIRMbss]

>Better chicken with teeth than Cows With Guns!

Yes, and remember,
roses on the piano
aren't the best thing . . .

[Tax-chick]

LOL!