I recently watched this clip of a man interviewing the guy in charge of a creationist museum. Among other things, when the visitor asked how the creationist believed that dinosaurs were once vegetarians when they had such sharp teeth and claws, the creationist said that Pandas have large teeth and claws, but only eat bamboo. I was able to tell by many other things he said that the creationist was quite ignorant and deluded, however I myself do not know off the top of my head how to explain the panda’s sharp fangs and vegetarianism. Fangs are usually used for hunting; if the panda eats mostly bamboo one may think that it might have evolved flatter incisors instead. Tell me, how does one explain this?
Pandas have the teeth and digestive systems of carnivores, but thanks to agenetic quirk, they prefer bamboo.
They’re a carnivore for whom meat doesn’t taste good. So they eat bamboo.
Have you ever tried eating bamboo?
Ok - I admit I haven’t either, but it is used in things like hard wood flooring and cutting boards, and I think it is generally considered a hard wood more than a grass (strength wise - not classification wise per se). I am pretty sure it isn’t really in the same realm as most vegetarians.
Of course. It’s in about half theChinese dishes I order. 
Pandas don’t have sharp teeth compared to carnivores that mostly eat meat.
They do retain pointed canines, but these probably mostly for defense, or for squabbles with other pandas. The molars are quite flat, as one would expect for an animal with a diet of tough plants.
Notice that the canines are much larger and sharper than in the panda, since other bears are much more predatory. However, the molars are still fairly flat, reflecting the bear’s omnivorous diet.
Canids are more carnivorous than bears. The canines are large and sharp, and now even the premolars and molars are sharp and pointed.
Cats are more carnivorous than canids, and the lion has very large and sharp canines and even sharper premolars and molars than a canid.
Horses are almost entirely vegetarian, but even horses have sharp canines, used especially in conflicts between stallions.
Musk deer and muntjac (another kind of deer) are vegetarian, but also have long canines for territorial fights.
Well I think I must have been confusing the “stalk” of the bamboo plant with its apparently more edible parts (unless you are tricking me with that photo). I see it (edible shoots) on Wikipedia now. I could have sworn I saw a video of a panda eating the stalk part and just assumed that is what they ate. Never saw it on the Chinese menu where I go, but I usually only order two dishes.
Pandas eat small bamboo stalks and leaves. I don’t recall the source for this, but I think they will strip the ‘bark’ from large bamboo stalks also.
In general terms, the implication of the OP is that characteristics that aren’t needed tend to disappear. That’s not true.
Well…it is, for certain values of “tend”.
Avoiding the “eats shoots and leaves” joke, I found this on Wikipedia:
Was this the interview that the OP saw? (scroll down for the video clip, but it’s worth reading the whole thing) I often find myself referring back to Dougie’s hard hitting journalistic inquiry, and it certainly seems that “The Special Times” is the perfect forum for all matters related to creationism.
Yeah, I would say that ‘tend’ is the appropriate term here. The tough part is determining what is ‘not needed’. As Colibri points out, the Panda’s sharp canines may still be needed. I could see them as being useful in eating bamboo. They would split the tough fibers of bamboo apart making the rest of the chewing and grinding easier. And Colibri’s photo series clearly shows that the Panda’s canines are considerably less pronounced than practicing carnivores, and even some vegetarians.
This doesn’t answer the OP, but I’d like to see the creationist’s argument turned around on him: Why would God create vegetarians with meat-ripping claws and canines?
Probably some kind of Panda original sin. Rational arguments aren’t going to work well with creationists.
To rip apart non-believers who ask questions like this?
That’s pretty weird if it is just an issue of taste for them. If a zoo tried feeding their panda meat with artificial bamboo flavours added to mask the meat taste, would that panda be just as healthy as one eating a real bamboo diet?
I’ll take “God Works in Mysterious Ways” for $2000, Alex.
It was indeed. 
Pandas like to eat meat though. They trap them with meat as bait. They’re just to slow to catch it.
I have to go look this up, because I know no one will believe me, but I swear I’ve read this in several places.
ETA: first thing I saw The Lazy Lizard's Tales: On Meat-eating Giant Pandas
There are many references to Pandas catching and eating small animals, and I gather they would scavenge like any other carnivore.
I don’t have all the source data used, but I suspect there is a misconception about the percentage of meat consumed by a Panda. Usually described as 1% or less of the Panda’s diet, this figure would be misleading if it was based on food weight. Pandas have to eat up to 30 pounds of bamboo a day because of the low nutritional value of the plant. A panda could be eating a couple of rats a week and stay in that 1% by weight range, but he would probably be getting a lot more than 1% of his nutrients from those rats.
I think in general, the fact that Pandas have survived and evolved over millions of years, during which time there must have been shortages of bamboo, shows that Pandas must be able to survive on more than bamboo alone. And since they are Carnivores, meat would be a logical alternative.