How Birds Lost Their Teeth 138
An anonymous reader writes A research team from the University of California, Riverside and Montclair State University, New Jersey, have found that the lack of teeth in all living birds can be traced back to a common ancestor who lived about 116 million years ago. From the article: "To solve this puzzle, the researchers used a recently created genome database that catalogues the genetic history of nearly all living bird orders--48 species in total. They were looking for two specific types of genes: one responsible for dentin, the substance that (mostly) makes up teeth, and another for the enamel that protects them. Upon finding these genes, researchers then located the mutations that deactivate them, and combed the fossil record to figure out when those mutations developed. They concluded that the loss of teeth and the development of the beak was a two-stage process, though the steps basically happened simultaneously. The paper states: 'In the first stage, tooth loss and partial beak development began on the anterior portion of both the upper and lower jaws. The second stage involved concurrent progression of tooth loss and beak development from the anterior portion of both jaws to the back of the rostrum.'"
It's Obvious (Score:4, Funny)
Have you ever seen a bird brush and floss? I haven't.
No wonder they lost all of their teeth.
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>Have you ever seen a bird brush and floss? I haven't.
>No wonder they lost all of their teeth.
Neither did humans until they started eating grains.
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Because I'm lazy, wikipedia:
http://en.wikipedia.org/wiki/T... [wikipedia.org]
A variety of oral hygiene measures have been used since before recorded history prior to the toothbrush.[6] This has been verified by various excavations done all over the world, in which chew sticks, tree twigs, bird feathers, animal bones and porcupine quills were recovered.
While not strictly brushing and flossing. It's pretty dang close.
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I have seen my chicken brush and floss his teeth when we were college dorm(itory) roommates. :P
How Birds Lost Their Teeth (Score:2)
Prehistoric hockey games?
Genetic testing (Score:2)
A friend of mine has a flock of feral peach-faced lovebirds that visits her bird feeder, there are about a dozen of them and they're probably several-generations out from the pet-escapees that started the flock. BIRDS WITH TEETH could probably survive without direct human care. And it would be frightening.
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There are several Palo-Geneticists that have been making reptilian looking chickens by turning on the gens involved in the development of teeth and tails. So far they kill the chick while in the egg and dies to view the changes and such under the microscope. The documentaries are online.
And yes you get to see the embryos with tiny teeth and a tail.
Anyone up for down payment on a franchines of dino-Chicken restaurants?
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From the... Isla Son-ra... I think it will try to kill meeee....
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Why do they have to kill them in the egg? I want to see what it looks like! Probably with horrible facial deformities, but come on... we kill billions of chickens painfully for food anyway, what's wrong with a couple more for science?
So which came first (Score:2)
They have the loss of teeth and the development of the beak, but where did the gizzard develop? They would not have been able to loose their teeth and develop a beak without one, and birds are the only animal (That I know of) that has one.
Plus gizzards are great when fried. ;)
Re:So which came first (Score:4, Informative)
The gizzard came first. I remember reading about dinosaur fossils found with small, smoothed stones where a gizzard would be. It seems likely that the saurian ancestors of birds already had gizzards. They had tearing teeth but no chewing teeth and depended on the gizzard to break down their food.
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They have the loss of teeth and the development of the beak, but where did the gizzard develop? They would not have been able to loose their teeth and develop a beak without one, and birds are the only animal (That I know of) that has one.
Plus gizzards are great when fried. ;)
According to Wikipedia [wikipedia.org], many reptiles including dinosaurs have/had gizzards.
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While it's true that birds are dinosaurs, I had thought that the "dinosaurs are reptiles" idea had joined so many others on the "trash heap of history"....
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Modern biologists tend to shy away from the idea of reptiles entirely. It's a bit of an ugly classification.
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"Reptile" is such a broad, catch-all classification it's almost worthless. Dimetrodon [wikipedia.org], for example, has always been classified as a reptile, but is more closely related to humans than it is to any modern reptiles. Crocodiles are much more closely related to birds (and dinosaurs) than they are to other reptiles like lizards and snakes.
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No way, José. Dipped in batter and deep-fried is the only way to go.
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Actually, your way doesn't sound too bad. Might have to give it a try. Can't quite come at gizzards or hearts, though.
Natural selection (Score:2, Redundant)
Nothing succeeds like a toothless budgie. Other birds flocked to the gene pool following the same example.
No hands, unable to brush teeth (Score:1)
No hands, unable to brush teeth. Any other question?
Wasn't it becsause...? (Score:5, Informative)
6005.99999 years ago, one of them flipped God the bird and so He did Smite them and lo their teeh were no more and there was lamentaion and suffering.
Also, beaks are much lighter than teeth, which was probably a significant factor.
Also also, if you're thinking about mammal teeth, you're probably imagining it wrong. One of the unique things about mammal teeth is their complexity relative to the other branches of the vertibrates. Studying mammal evolution has been described as an exercise in studying teeth.
It's thought this advanced tooth development went hand in hand with warm blooded development during the pre-mammal period as more adavanced, inerlocking teeth were requied to mash up food better for quicker digestion which was required for a faster metabolism.
Most reptile teeth look primitive by comparison. Except that simple teeth are easily replacable and so reptiles can regrow lost teeth much more easily (later on some mammals in the ungulates developed open roots for continuous growth which was useful for grazers, whereas others hae a large stock of teeth then starve to death when they run out). The specialisation makes these much harder.
It seems likely that birds did not have the great teeth for supporting warm blooded metabolisms, but rather the simple, robust general purpose teeth of other reptiles, so in this sense there were not losing nearly as much. They also solved the grinding problem in a different way, using a gizzard (this may well predate birds: crocs have gizzards as well and it is speculated that some dinosaurs did). As a result they were replacing the bit that grips and possibly does some initial cutting of food with a much more lightweight structure.
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Where did the extra 6 years come from, heretic? Cardinal Fang! Fetch... THE COMFY CHAIR!!!
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Creation happened on Oct 23rd at Noon in the year 4004BC (Don't ask about which timezone), so the posters math is bad and it should be more like 6018 years ago (too lazy to figure out the fraction)
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(Don't ask about which timezone),
There was only one timezone then, as the earth had not been made spherical yet. Its all there in Genesis.
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Cool research (Score:4, Funny)
Interesting reports like this can be rare as hens teeth.
They did not floss, that is why (Score:2)
I can't go into too much detail.. (Score:2)
There are only 48 bird species? (Score:2)
*Sigh* (Score:2)
Paper tech beats the internet this time (Score:2)
I already read this story on my old fashioned paper newspaper last Friday. Is internet news slow today, or is my newspaper unbelievably fast?
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And so you remind us that there was a movie, too. You insensitive clod.
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In most cases, HG Wells' novels are vastly improved upon by their movie adaptations (even starring Tom Cruise), with the notable except of the The Island of Dr. Moreau.
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In most cases, HG Wells' novels are vastly improved upon by their movie adaptations (even starring Tom Cruise)
Is this quite as true of the 1960 and 2002 movies of The Time Machine? I watched both and my first disbelief breaker was how English survived 800 millennia when Proto-Indo-European fractured into modern languages in only six.
Oh wait, the Animal Crossing anime isn't a sequel to The Island of Dr. Moreau, is it?
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Is this quite as true of the 1960 and 2002 movies of The Time Machine? I watched both and my first disbelief breaker was how English survived 800 millennia when Proto-Indo-European fractured into modern languages in only six.
Oh wait, the Animal Crossing anime isn't a sequel to The Island of Dr. Moreau, is it?
As a sci-fi fan, I struggle with this wherever I encounter it: Dr. Who, SG-1, and yeah, both adaptations of the Time Machine. In the last case, I think that taking the artistic liberty of adding an actual story, with a real conflict to be resolved, necessitates communication of some kind. While the solution in both movies (people still speak English!) leaves something to be desired, it is still better than the boring temporal travelogue that makes up the source material.
Dances With Morlocks (Score:2)
In the last case, I think that taking the artistic liberty of adding an actual story, with a real conflict to be resolved, necessitates communication of some kind.
The problem in the novel is "I have to get my time machine back", and the conflict is between the Time Traveller and the environment. Learning how to communicate with the locals is a subproblem of this problem.
While the solution in both movies (people still speak English!) leaves something to be desired
It just bugs me that the writers of both adaptations were afraid to spend a mere three minutes of the script on language elicitation. A feature film is not like an episode of Star Trek: $subtitle where you have 44 minutes to tell a story with no time to spend on language-of-the-week. It could have bee
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It's explained in Doctor Who: Time Lords have neat communication abilities that they can share with others. That way, everything sounds like English to the Doctor's companions.
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There is at least some brief attempt to explain this: English is no longer a widely spoken language, but there is a religion-like effort to preserve it as a ceremonial language, aided by conserving any text in a sufficiently durable form.
It's not a very good explanation considering the time scales involved, but it's better than no explanation at all. It does have some historical basis. Hebrew, for example, all but died out for a time before being revived by religious schoolers. Eight hundred thousand years,
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Oh, everything I said above was in relation to the film, not the book. The book has it much simpler: No-one in the future speaks english at all.
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There was a book about this. It was called Protector [wikipedia.org].
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The first gender based, non-single cell organism would have had to been born with the ability to successfully reproduce the first time AND so would its compatible mate and have the ability to sustain that new life.
Flowers. Both sex organs on one plant, but now can exchange genetic information. But diversity wins out, so genders become a distinct genetic advantage. I assume that the same with animals would be convergent evolution, but probably the same starting path.
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Heh "organs". Look at single cell organisms today and you will find our idea of sex is so..... specific and limited.
These suckers don't have "sex organs" they actually toss out copies of their genetic mateiral for others to grab and use. If anything the sex organs provide a method for filtering and slowing down the messy process of gene exchange, rather than enabling it.
I would bet that the origins of sexuality are actually related to horizontal gene transfer and mechanisms organisms developed to tone down
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"...they actually toss out copies of their genetic mateiral (sic)..."
This is /.; we're familiar with the process.
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It's the exact opposite. Sexual organs enable exchange of extremely high amounts of information. Single cell organisms are exceedingly simple in comparison, and as a result the method you talk about works well for them.
Attempting the same with more complex organisms would result in overwhelming amount of failures due to permutations being lethal or disabling in nature far more often than not.
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I don't see how that is opposite, of course that makes sense. You could even say that turning off or severely restricting HZT is hard to see as anything but a requirement for developing as a multicellular organism that lives and dies by its coordination.
My point was really about the other end.... trying to imagine the evolution of sexual reproduction from simple cell lines that only pass genes vertically through the generations....I can see why that is hard, but we don't have to imagine that since, it was u
Re:Wasn't there a book about this? (Score:5, Informative)
The problem is you are not smart enough (no one is - except perhaps god) to understand all the intervening steps.
You don't 'give up' teeth, you get a mutation and are stuck with it. They are not making conscious decisions to evolve, that is just plain ignorance. If you can find a way to survive without the teeth, you continue on. Eventually you get another mutation, and maybe it evolves to take the place of something you lost.
Birds found a way to survive without teeth before they gained a beak. Possibly it was those rocks some birds swallow and use to grind up large chunks of food (I don't know when or if all do this).
Maybe teeth became a liability. People used to die from a rotten tooth, maybe there was an epidemic of bird tooth infecting microbes. It doesn't matter.
As for gender based on-single cell organism, you have that wrong also. Sex evolved from eating - the victim's genes survived inside the single cell that tried to eat it, and it's grew from there. At that point all those single celled life forms were hermaphrodite - they could eat or be eaten and their DNA would survive in the eater. Eventually, the hermaphroditic single celled life forms developed into two varieties - one that could eat and absorb the DNA (female) and the other that could be eaten and pass on their DNA (male).
Also there was no clear line between single celled life forms and multicelluar life forms. First came colonies that learned to cooperate but could also survive on their own.
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The problem with macro evolution is the inherent issues with the "in between" stages that are mostly useless, being neither good for one thing they are coming from or good for the thing they are changing into.
The example I use is Butterflies, which change from a crawling creature to one that flies, mid life. Incredible "random" feat if you ask me.
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Re:Wasn't there a book about this? (Score:4, Insightful)
Apparently they were more successful than the ones with just teeth. That's all it takes.
It doesn't even necessarily take that much. Sometimes the mutated offspring only has to be not so much worse that it can't manage to reproduce. It could potentially be slightly worse, as long as there's enough room for both to survive.
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They don't even have to be more successful all the time. Those could have been the underdog not so well suited to the environment, but there was a famine or flood or other event. The niches open up for whatever can move in like squatters. Either the local competiton dies off and the previous underdog is left alone there, or the underdog migrates to a less desirable environment that the competition doesn't like.
You see similar things today. We tend to think of very select niches for some species, such as
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Exactly my point. Half Beak, Half Teeth doesn't make sense.
Umm, the universe is not limited to doing only those things that make sense to YOU. I'd even say it's pretty damn arrogant of you to presume your powers of comprehension are literally some kind of universal limiting factor.
"I can't figure out how evolution could have worked, ergo it must be impossible."
Sure. The powers of your brain cells place limits on biological processes that happened hundreds of millions if not billions of years ago? Uh huh. I bet your unicorns fart butterflies, too.
Hell, just for
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"I can't figure out how evolution could have worked, ergo it must be impossible."
Actually, having a brain causes me to think about such things. I do understand evolution. And if it were an advantage, at all, some species would likely to have both. But none exist. So having half teeth and half beak wasn't so good after all, but apparently it was good enough to get from teeth to beak for all birds, and not just some.
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People forget that there is a lot of randomness and luck in evolution. Disasters happen (volcanoes, asteroid strikes are some extreme examples) causing genetic bottlenecks. If the birds with half beaks and teeth had the bad luck to get wiped out in a natural disaster, doesn't matter how much of an advantage they had, the ones lucky enough to further away from the disaster reproduce.
In some ways it's survival of the luckiest as well as the fittest and since luck seems to be just a random process, it can't be
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Perhaps beaks evolved via bills. I believe duck billed platypuses and some duck billed dinosaurs also had teeth, though small.
It's a shame the fossil record is so sparse as some things we'll never know for sure.
Re:Wasn't there a book about this? (Score:5, Insightful)
The example I use is Butterflies, which change from a crawling creature to one that flies, mid life. Incredible "random" feat if you ask me.
It's not random. The ability for adult insects to fly evolved gradually. That has nothing to do with the fact that insects go through metamorphosis, which most likely evolved independently and prior to the capability of flight
Your argument makes as much sense as saying: "I don't believe evolution because people can talk using air even though they spend 9 months sealed up in a bag of water."
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Look at today's flying squirrels. It's not hard to figure out how you get from walking mammals to this species, nor from flying squirrels to fully winged creatures. Why would it be any harder for insects to follow the same path?
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Every member of a species is an in-between stage. You carry with you mutations in your genes. Yes, useless. Doesn't prevent you from procreating. If you do, your genes will end up in another individual who happens to get another mutation. Perhaps that does something; perhaps it does and it tweaks a protein's specificity. Mutations that don't have an effect now may have one in the future when more mutations build up. Mutations are not directed, occur without purpose (selection is directed: you get offspring
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The problem I see with many people is that they see evolution as binary. Everything must be an advantage to be passed on and that mutations are bad. No, mutations are normal with some providing advantages and some are disadvantages. And as you pointed out, some traits have no effect whatsoever. Other traits appear to be a disadvantage or an advantage given the right environment. Fair skin, for example, is advantage in places like Norway where more vitamin D is produced with less light. It is a terrible disa
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The example I use is Butterflies, which change from a crawling creature to one that flies, mid life. Incredible "random" feat if you ask me.
That's arguably less incredible than all of the animals that change from small, fragile, immobile white (or tan, brown, etc.) balls into fast, flying creatures.
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Not really. The chick doesn't wrap itself up in an egg shell.
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The example I use is Butterflies, which change from a crawling creature to one that flies, mid life.
Except we have a pretty good idea of how it happens.
Do you believe in eggs? That is, do you believe in organisms--including insects--that reproduce by laying eggs? And do you believe that those eggs don't have shells?
If so, can you imagine a mutation that makes an egg very slightly motile? The outer layers of such eggs is typically some kind of protein. Suppose that there is a mutation such that after the egg has grown to a certain size there is a biochemical response that causes the protein coat to contra
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The problem with macro evolution is the inherent issues with the "in between" stages that are mostly useless, being neither good for one thing they are coming from or good for the thing they are changing into.
That seems like eerily familiar with the creationist concept of irreducibility which is considered to be a flawed concept. Two things to remember is that evolution is not goal driven and exaptation [wikipedia.org] has been demonstrated countless times.
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Evolution is results driven, not goal driven that is true. Now figure out how the results of two partial stages has an advantage over surviving that doesn't last for any length of time.
Stage A has advantages, as experienced in animals having A
Stage B has advantages, as experienced in animals having B
No animals have A and B, but somehow we are supposed to believe that animals having A/B existed and had enough advantage to beat out those having A, on their way to having B, but the A/B didn't beat out those wh
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Evolution is results driven, not goal driven that is true. Now figure out how the results of two partial stages has an advantage over surviving that doesn't last for any length of time.
Again, evolution is not goal driven. Your second sentence contradicts your first admission. A trait survives when it provides or benefit or is neutral. You keep forgetting a trait that provides no advantage can be passed. The issue is really if a trait that proves to be a disadvantage affects a species ability to procreate.
No animals have A and B, but somehow we are supposed to believe that animals having A/B existed and had enough advantage to beat out those having A, on their way to having B, but the A/B didn't beat out those who ended up B only.
I can take from your long-winded and illogical sentence that you're never seen a dolphin or whale in your life? ,a href="http://en.wikipedia.org/wiki/Cetacea">Cetaceans are water anima
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Again, evolution is not goal driven.
Animals have A or B, but AB is not evolutionary advantageous to survive. This is not goal, it is a simple statement of what exists. The explanation is that A moves to B along an evolutionary line, where none of the AB survive long term. This is a result, not a goal. Further evidenced by lack of any animals that progressed from B back to A (result, not goal).
As I said, A has advantages, B has advantages, but AB appears to have neither, due to lack of any remaining AB hybrids. A mutates and starts progressing
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Animals have A or B, but AB is not evolutionary advantageous to survive.
Your binary thinking is a major flaw in your thinking. Nature is not necessarily binary and you asserting AB is not advantageous without evidence. There are many examples of gradients like the fact that humans have remnants of a third eyelid. Transitional forms are not AB entirely.
This is not goal, it is a simple statement of what exists. The explanation is that A moves to B along an evolutionary line, where none of the AB survive long term.
Again, what? You are stating as a fact that none of AB survive long term. You don't know that. The fossil record clearly shows that transitional forms have existed and do exist like the giant panda..
This is a result, not a goal. Further evidenced by lack of any animals that progressed from B back to A (result, not goal).
Again stating something as fact
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Teeth or Beaks are binary in nature, we don't see any creatures with both. Your rant about binary nature is flawed, because while nature isn't binary, sometimes the results are.
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Teeth or Beaks are binary in nature, we don't see any creatures with both. Your rant about binary nature is flawed, because while nature isn't binary, sometimes the results are.
You are aware that chicks have teeth right? It's how they break out of their eggs. They lose their tooth quickly after being hatched but they do have teeth for a short period. As for them not having teeth generally, this evidence shows they lost their teeth over millions and millions of years. I'm not sure where you get the idea of "temporary."
As for rants, keep stating that A must become B. That's not nature. A can still remain as A while a population of A becomes C. That's how most species evolve. You n
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The conditions species live in aren't constant. Advantages of A and/or B fluctuate over time. If an animal has A, and the environment suddenly favors B, those closer to B win. For a while some animals will have both.
However, every feature comes at an energy cost, so animals quickly let what they don't need atrophy. If in the current environment B beats out A+B minus extra energy to generate both, then they will settle at B only.
At any rate, every organism is a mixture of thousands of features, from A0 to Z9
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Evolution is imperfectly results-driven, being stochastic rather than deterministic. A trait that confers an advantage may not come to dominate, for a variety of reasons. It may be (necessarily or accidentally) linked with a trait that's a disadvantage. It might not be enough of an advantage to overcome bad luck. It may diverge into a new species that's then wiped out somehow.
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People get macro evolution wrong because they're stuck thinking that evolution is about solving an optimization problem: ie, more evolution means better creatures. Except that evolution is about adaptability into the environment, into particular niches, and so forth. There are no higher or lower organisms, they just are. No in between stages, they just are. Sure, there are things between dinosaurs and birds, but then perhaps the bird itself is just an in-between stage between pre-birds and post-birds. H
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Before you fly, you can glide. Before you can glide, you can slow your fall. Before you can slow your fall, you can use it to warm/cool your body. Spread the partial wing in the shade when hot and you increase surface area, cooling yourself down. Do the same in the sun and you get more warmth
Basically, if the effect is really mostly useless than that also means it is not particularly bad - such as being born an albi
Re:Wasn't there a book about this? (Score:5, Insightful)
Why give up teeth
Because as things changed and the years passed they became more of a hindrance than a help to birds (or their ancestors) and so those offspring born with fewer teeth, or smaller teeth, were better at surviving and having offspring.
how to convince your unborn offspring to do take it to the next step.
Why would any "convincing" be required? The offspring are likely to face the same challenges as their parents. If they've got traits that help them survive better than their peers - such as fewer or smaller teeth - then they'll pass these on to their offspring. Then, in turn, those offspring will be facing the same pressures again. So once again, among those offspring, those with fewer or smaller have a better chance at surviving than their brothers and sisters (and cousins).
You would expect these animals to be superior to us and make conscious decisions to change their DNA, to evolve
What animals are you talking about? No animal needs to make a conscious decision to evolve. It's already taken care of by inheritance and selection pressure.
As long as you've got a mechanism for children to be largely similar to but ever-so-slightly different from their parents, and a reason for some of those offspring to reproduce more successfully than others because of those differences, then evolution is inevitable.
Re:The beaks won (Score:4, Insightful)
It's superior if and only if you need to dig for grubs in dirt and wood with your mouth.
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Re:The beaks won (Score:4, Insightful)
I RTFA, big mistake. Nobody knows, and all arguments are counterdictory to each other. In other words, an article about we don't know why, and we are saying we don't know why. I find myself not breathless waiting for the next article from Captain Obvious.
Good science involves being very clear about what you don't know.
Re:The beaks won (Score:5, Funny)
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Counter and contra are technically interchangeable. Though contra is more inline with the root latin word (contra).
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I think it has more to do with being light weight since birds fly. After all, not all birds dig for grubs. Of course, not all birds fly anymore, but maybe the common ancestors did.
Another thing, birds evolved from reptiles. I watched the science documentary series 'Your Inner ...' (Inner Fish, Inner Reptile, etc). They mentioned that reptiles can replace their teeth but the teeth are undifferentiated, whereas mammals, who only get two sets, have them custom designed with a tight fit so some are good for
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RFTA
Flying mammals like bats have the ability to fly without forgoing teeth for a beak.
Archaeopteryx, widely considered the "first bird." . . . flew, and sported plumes and chompers.
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So I got this beak installed, and now I'm having trouble playing the trumpet. What's the solution?
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Don't share.
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You're obviously not a marketer. Bully for you. :)
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Lips may be a little better, but what you really want for soup is a long, flexible nose like an elephant.
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Take a look at a goose's mouth. There are serrations in the mouth. I'm not sure if they are directly on bone or what the substance is which holds them.
But yeah. Less habitat for bacterial to hide out, lay down calcareous concretions and live within while they continue to secrete more acids.
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If birds had teeth, they would evolve into mammal-eaters and pose great threat to any mamal that lives above surface.
Eagles, hawks & owls all eat mammals.Sure, they're mice, rabbits, small cats, etc., but they're still mammals.
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There were bigger birds once, eating bigger mammals. Haast's eagle, for one. Bloody huge, still capable of flight. The local tribes still tell legends of the terrifying creatures which could once descend from above and carry off human children.
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I thought they had uric acid or urea or such instead of urine.