Posted on 07/03/2006 12:32:51 PM PDT by Al Simmons
In the 1993 movie Jurassic Park, one human character tells another that a Tyrannosaurus rex can't see them if they don't move, even though the beast is right in front of them. Now, a scientist reports that T. rex had some of the best vision in animal history. This sensory prowess strengthens arguments for T. rex's role as predator instead of scavenger.
Scientists had some evidence from measurements of T. rex skulls that the animal could see well. Recently, Kent A. Stevens of the University of Oregon in Eugene went further.
He used facial models of seven types of dinosaurs to reconstruct their binocular range, the area viewed simultaneously by both eyes. The wider an animal's binocular range, the better its depth perception and capacity to distinguish objectseven those that are motionless or camouflaged.
T. rex had a binocular range of 55, which is wider than that of modern hawks, Stevens reports in the summer Journal of Vertebrate Paleontology. Moreover, over the millennia, T. rex evolved features that improved its vision: Its snout grew lower and narrower, cheek grooves cleared its sight lines, and its eyeballs enlarged. ...
Stevens also considered visual acuity and limiting far pointthe greatest distance at which objects remain distinct. For these vision tests, he took the known optics of reptiles and birds, ranging from the poor-sighted crocodile to the exceptional eagle, and adjusted them to see how they would perform inside an eye as large as that of T. rex. "With the size of its eyeballs, it couldn't help but have excellent vision," Stevens says.
He found that T. rex might have had visual acuity as much as 13 times that of people. By comparison, an eagle's acuity is 3.6 times that of a person.
b
T. rex might also have had a limiting far point of 6 kilometers, compared with the human far point of 1.6 km. These are best-case estimates, Stevens says, but even toward the cautious end of the scale, T. rex still displays better vision than what's needed for scavenging.
The vision argument takes the scavenger-versus-predator debate in a new direction. The debate had focused on whether T. rex's legs and teeth made it better suited for either lifestyle.
Stevens notes that visual ranges in hunting birds and snapping turtles typically are 20 wider than those in grain-eating birds and herbivorous turtles.
In modern animals, predators have better binocular vision than scavengers do, agrees Thomas R. Holtz Jr. of the University of Maryland at College Park. Binocular vision "almost certainly was a predatory adaptation," he says.
But a scavenging T. rex could have inherited its vision from predatory ancestors, says Jack Horner, curator of paleontology at the Museum of the Rockies in Bozeman, Mont. "It isn't a characteristic that was likely to hinder the scavenging abilities of T. rex and therefore wasn't selected out of the population," Horner says.
Stevens says the unconvincing scene in Jurassic Park inspired him to examine T. rex's vision because, with its "very sophisticated visual apparatus," the dinosaur couldn't possibly miss people so close by. Sight aside, says Stevens, "if you're sweating in fear 1 inch from the nostrils of the T. rex, it would figure out you were there anyway."
Stevens, K.A. 2006. Binocular vision in theropod dinosaurs. Journal of Vertebrate Paleontology 26(June):321-330.
>.How does sin enter into the fact that a tree gets struck by lightning, falls and dies. Did the tree "sin"? <<
Atually you are missing the whole foundation of this sin thing. All of creation is suffering for the sin of man.
On a side note, the climatic conditions before the fall of man were such that lightning was probably very unlikely. You also have to be careful about taking some phrases too literally. I don't mean like bible thumpers do, I mean like where the bible calls insects "four footed" proves it is a bunch of hooey. It is attemting to pick at irrelevant nits. When the bible speaks of death, I can only assume it means what a reasonable man would think of - it would preclude clumps of grass, etc.
"Thanks! I wanted you to take a stand."
It was already pointed out to you before.
"Now, why is it that the fast-breeding alligator is so devoid of **random** mutations?"
They aren't.
>>I think the fundamentalists are missing the point that God made man in His own image --namely immortal.<<
That is not how others name it, nor is it what the bible says. It is conjecture. Others say it means "with a spirit". And the tree that brought death was the tree of "knowledge of good and evil". And God said the man will "be like US".
Just something for some to ponder here.
Change in a population is the result of selection, not the mutation rate.
Notice my posts were in 3rd person. I do not identify these beliefs as mine. I merely answered the question as to why some get so exercised over evolution. They believe it negates Christ's redemptive death.
In that belief system, prior to the fall, there was no death at all from anything. Viruses and bacteria would have been happy little symbiots, not lethal organisms.
Sin broke something and allowed death to enter perfect creation. From the moment of original sin, creation started to age and malfunction and death began to occurr.
*Hissing? It was a democrat racoon
She was trying to put a hex on me, that's for sure!
>>They believe it negates Christ's redemptive death.<<
I gotta say this: although I am a professing Christian now, I didn't buy "evolution" long before I became one. The problem was that I just didn't like something so significant being crammed down my throat with no evidence, and yet with such finality and conviction.
It is probably that personality trait that has also made me a conservative from the cradle. I don't like being told what to believe without evidence.
Evolution requires millenia of death because it needs huge numbers of generations for random mutations to beget species. Which means lots of critters had to breed and die for really looong periods of time.
Is it a big leap to assume that all species were immortal before the fall? Creation was "good" so why should it be assumed that it's "nature was red in tooth and claw" like our current environment? The "God saw that it was good" is what they hang the belief in no death on.
*Do you mean a migratory rabbit or an African rabbit?
*This rabbit was photographed in my back yard. Look at his eyes and tell me he is not a descended from Algerian migratory rabbits
It looks like we don't differ much on this. I separate creation into two groups:
1. Man
2. Natural resource
I have intellectual problems with the concept of no death before the fall. After all, what were Lions teeth for back then, stringing hammocks together? And how did you get two of them to sit still?
I guess I don't like have theory shoved down my throat, either. What makes anyone believe that there must be "no death" before something can ultimately be judged "good"? As Christ himself showed us, some things are worth dying for.
As for myself, I do not really see that evolution and creation are mutually exclusive. Perhaps the number of days taken are different, but who's to judge God's calendar? After all, if a thousand years is but a second to God....
I never bought evolution as a explanation either. Mostly because I thought (as a young child) that if new species do come into being over time then I should be able to see one now or somebody should have.
I remember the teacher telling me it takes too long and we wouldn't notice. And the unspoken reply was "bullsh*t, you might not notice, but I would and any even half competent farmer would".
And in spite of all that fine breeding and herdsmanship, animals revert to the plodding main in just a few short generations of unsupervised crossings.
I just figured if man couldn't create a new species by design then nature certainly couldn't do it by chance.
"It's "the wages of sin is death" paradox. If death is the result of sin (and sin came from man) then all the millenia of death from evolution prior to man can't exist or if there were millennia of death prior to man then the "sin caused death" isn't true which means Christ died for nothing and our sin is not expiated by it."
Wow. This is the most confused thing I have ever seen.
You confuse death in a dino with death as it applies to Man. Man has a soul and a dino was just a biological system--no different than, say a tree. You go on to confuse death as the Bible defines it with the cessation of a mans biological life.
Making T. Rex homes became a low priority.
So in order to keep your head from exploding..... I'm just explaining the belief system.
If evolution does not work by chance, i.e. random mutation, then what does it work by?
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.