Questions re: Jurassic Park

[NPK]

Just watched Jurassic Park again on TV....and have some questions for the dinosaur lovers here.

 

1. How do they know that Tyrannosaurus rex can only see movement (ie. if you stood completely still they could not see you)

 

2. How do they know veloci raptors (sp?) hunt from side-on in groups?

 

Or are there just things made up by the movie makers?

[the tree]

1. How do they know that Tyrannosaurus rex can only see movement (ie. if you stood completely still they could not see you)

By observing animals alive today.

2. How do they know veloci raptors (sp?) hunt from side-on in groups?

I don't know about this one, I'd imagine it's either to do with the position of bite marks on thier prey or:

just things made up by the movie makers?

[herpguy]

1. How do they know that Tyrannosaurus rex can only see movement (ie. if you stood completely still they could not see you)

That theory was proven wrong.

 

2. How do they know veloci raptors (sp?) hunt from side-on in groups?

Not sure, but maybe fossilized tracks gave them a hint.

 

Or are there just things made up by the movie makers?

I'm sure most of the things the dinosaurs did were made up.

[Xyph]

The thing with Tyrannosaurs only seeing movement comes from thinking dinosaurs were essentially just very large versions of modern reptiles, most of which, I think (such as crocodiles), lack colour vision. I'm pretty sure that more recently, though, evidence of some sort has surfaced that dinosaur vision was probably closer to bird vision, meaning they would have had good colour vision. So, the idea that T-rex could only see movement is quite outdated.

 

Evidence for velociraptors as pack hunters comes from fossil arrangement (large groups around much larger prey, and such) and that the claw was probably best for clinging on rather than slashing, indicating that they overwhelmed larger prey by sheer numbers, causing them to bleed to death, rather than direct lone attacks.

 

 

I think that's it, anyway. Apparently velociraptors were also probably one of the more intelligent dinosaurs, but nowhere near as intelligent as they were portrayed in the film.

 

I remember being pretty disappointed when I found that out.

[Mokele]

1. How do they know that Tyrannosaurus rex can only see movement (ie. if you stood completely still they could not see you)

 

Made up plot device.

 

By observing animals alive today.

 

AFAIK, there are no animals with vision that bad who don't live underground or in caves. IIRC, even bats have better vision than that.

 

The thing with Tyrannosaurs only seeing movement comes from thinking dinosaurs were essentially just very large versions of modern reptiles, most of which, I think (such as crocodiles), lack colour vision. I'm pretty sure that more recently, though, evidence of some sort has surfaced that dinosaur vision was probably closer to bird vision, meaning they would have had good colour vision. So, the idea that T-rex could only see movement is quite outdated.

 

Actually, reptiles (aside from burrowers) have pretty good vision, including color vision. In fact, IIRC, gater snakes have an all-cone retina. Crocodilians *definitely* have good color vision; they can recognize keepers by clothing, and will approach visitors wearing similar colors.

 

2. How do they know veloci raptors (sp?) hunt from side-on in groups?

 

Side-to-side: that was just made up. It's possible, and it's a strategy employed by some group-hunters today, to it's not impossible, but there's no actual evidence for that method in particular.

 

Raptor pack hunting: shoddy evidence that's actually somewhat questionable. The only direct evidence we have is one find, a Tenontosaurus with 3 Deinonychus skeletons around it and with bite marks on the bones and broken teeth. However, this doesn't prove the raptors didn't just group together by chance because the 3 or more individuals found some yummy carrion.

 

This doesn't mean they *didn't* hunt in packs, only that it's nowhere near the iron-clad fact people think it is, and is really more of a vague guess.

 

Not sure, but maybe fossilized tracks gave them a hint.

 

Actually, the only know dromaeasaur trackway appears to be of a solitary individual.

 

I'm sure most of the things the dinosaurs did were made up.

 

Oh yeah. Dilophosaurus didn't have a frill, and there's no evidence of venom apparatus. Brachiosaurus couldn't rear up onto its hind legs.

 

Evidence for velociraptors as pack hunters comes from fossil arrangement (large groups around much larger prey, and such) and that the claw was probably best for clinging on rather than slashing, indicating that they overwhelmed larger prey by sheer numbers, causing them to bleed to death, rather than direct lone attacks.

 

Actually, aside from the find mentioned above, the only other find showing raptor hunting behavior is a lone velociraptor attacking a lone protoceratops.

 

And the study about the claw being for clinging was so massively flawed as to be worthless. Unsuprisingly, it was funded by a TV station.

 

Mokele

[Skye]

This off-topic, but I was wondering this today: Are the fossilised shed skins of reptiles ever found?

[Mokele]

Not so far as I know. Delicate things tend of fossilize badly, even bones. Shed skins are far more delicate, and are composed of nothing more than keratin, so are pretty biodegradable too.

 

Mokele

[bascule]

My biggest problem with Jurassic Park was the idea that you could get a mixed up hodge podge of genes from the belly of a mosquito trapped in amber for the past 65+ million years, and somehow splice in frog DNA between the segments (WTF? Why the hell are they using frogs?) and all the sudden you have the strands of DNA you need to grow dinosaurs.

 

That's like saying that if you take the original masters of the Beach Boys Smile which Brian Wilson cut up and burned in frustration, and try to splice together the original songs by filling in the missing bits and pieces with some Monkees tunes that what you'll end up with will be anywhere close to the original song.

 

WTF?

[herpguy]

Actually' date=' reptiles (aside from burrowers) have pretty good vision, including color vision. In fact, IIRC, gater snakes have an all-cone retina. Crocodilians *definitely* have good color vision; they can recognize keepers by clothing, and will approach visitors wearing similar colors.[/quote'] Are you sure about this? My collared lizard only chases after moving crickets, I think it's because of his eyesight. Please tell me the correct reason why if I'm wrong. Thx.

[Mokele]

My biggest problem with Jurassic Park was the idea that you could get a mixed up hodge podge of genes from the belly of a mosquito trapped in amber for the past 65+ million years, and somehow splice in frog DNA between the segments (WTF? Why the hell are they using frogs?) and all the sudden you have the strands of DNA you need to grow dinosaurs.

 

Well, the idea is that because the DNA sequences for most vertebrates are very similar, and that if you have the code of one organism, you have most of the code of others. Of course, this ignores the fact that if you have 10% of an organism's genome, you're probably missing both 90% of the common stuff but also 90% of the "special" genes that make that organism different. Frogs were used because Xenopus laevi (the African Clawed Frog, which can change sex as described in the movie) is a common "model system" for developmental genetics.

 

Are you sure about this? My collared lizard only chases after moving crickets, I think it's because of his eyesight. Please tell me the correct reason why if I'm wrong. Thx.

 

Movement generates a strong feeding response in reptiles (most of whom are predators), but they can see non-moving objects just fine. They just don't care as much, if at all, unless it's food.

 

Mokele

[starbug1]

Is it at all possible to retrieve intact dinosaur DNA from a mosquito, rather than just a degenerate 10%? And what are the rules on DNA preservation and decay?

[Mokele]

Not really. AFAIK, DNA isn't very stable even within an organism's lifetime and with active metabolic effort to maintain it. Once the organism is dead, it decays fairly rapidly, and over 65 million years I doubt there's be even recognizable base-pairs left.

[herpguy]

Not really. AFAIK, DNA isn't very stable even within an organism's lifetime and with active metabolic effort to maintain it. Once the organism is dead, it decays fairly rapidly, and over 65 million years I doubt there's be even recognizable base-pairs left.

I heard about this t-rex that paleontologists found earlier this year with cells still inside of its fossilized leg. The scientists said the probability of cloning it is very low, but they will not take the risk.

If it's fossilized quickly maybe the DNA will still be in good condition.Please give me more information if you know what I'm talking about.

[starbug1]

The scientists said the probability of cloning it is very low

 

...but there's still a chance.

[Mokele]

I heard about this t-rex that paleontologists found earlier this year with cells still inside of its fossilized leg. The scientists said the probability of cloning it is very low, but they will not take the risk.

If it's fossilized quickly maybe the DNA will still be in good condition.Please give me more information if you know what I'm talking about.

 

Well, from what I know, what was inside the bone was more likely just protien, such as collagen, though there might be remnants of blood cells. However, the probability of any actual DNA remaining is absolutely tiny. Protiens are more stable, and ones like collagen are especially so (since it is, after all, a structural protien).

 

The possibility of cloning a dinosaur from any DNA we did find would be, to use an analogy of an LJ friend, like knitting a Lambourgini out of steel wool.

 

Mokele

[lightwave]

Quite a lot of what Hollywood does is believable. I'm sure they do their research too. But the story comes first and many elements of science will be changed to suit scripts.

 

The film was good, the book good too. If only scientists could write science fiction and we'd get more accurate representations of science in film.

[herpguy]

Well' date=' from what I know, what was inside the bone was more likely just protien, such as collagen, though there might be remnants of blood cells. However, the probability of any actual DNA remaining is absolutely tiny. Protiens are more stable, and ones like collagen are especially so (since it is, after all, a structural protien).

Mokele[/quote']

You're right, I was reading Discover Magazine and they said that there was no DNA found in the t-rex.

[herpguy]

By observing animals alive today.

When I went to the San Diego Wild Animal Park, the tour guide said that the Jurassic Park makers watched the African animals to see how they moved.