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New Study Shows Tyrannosaurus Rex Evolved Advanced Bird-Like Binocular Vision
Science News Online ^ | June 26 2006 | Eric Jbaffe

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.

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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.


TOPICS: Religion; Science
KEYWORDS: atheismsucks; atheistdarwinists; bewareofluddites; creationism; crevolist; darwindroolbib; darwinwasaloser; dinosaurs; evolution; flyingbrickbats; godsgravesglyphs; guess; heroworship; ignoranceisstrength; junk; paleontology; patrickhenrycrap; pavlovian; pavlovianevos; shakyfaithchristians; trash; trex; tyrannosaurus; useyourimagination; yecluddites; youngearthcultists; youngearthidiocy
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To: js1138
"The source of variation does not matter."

Incorrect. The source of the sequencing is the entire debate!

If the data sequencing is random, then Evolutionary Theory wins.

If the data sequencing is biased, then Intellgient Design wins.

581 posted on 07/06/2006 9:00:24 PM PDT by Southack (Media Bias means that Castro won't be punished for Cuban war crimes against Black Angolans in Africa)
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To: Southack

http://www.freerepublic.com/focus/f-news/1634489/posts?page=1#1


582 posted on 07/06/2006 9:02:43 PM PDT by js1138 (Well I say there are some things we don't want to know! Important things!")
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To: Southack

http://www.freerepublic.com/focus/f-news/1634489/posts?page=57#57


583 posted on 07/06/2006 9:04:48 PM PDT by js1138 (Well I say there are some things we don't want to know! Important things!")
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To: js1138
"One of our most surprising findings is that an estimated 20 million point mutations gave rise to just six populations ... Though millions of mutations in the target gene are believed to have occurred, only about 700 of those were capable of creating a new variant..."

An estimated 20 million point mutations only misses your claimed "every possible variation occurred" by 20 orders of magnitude.

Nice try, though. Most Darwinists don't even get that close.

No cigar for you, though.

584 posted on 07/06/2006 9:08:32 PM PDT by Southack (Media Bias means that Castro won't be punished for Cuban war crimes against Black Angolans in Africa)
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To: Southack

Check out the actual article. The entire genome is not relevant to the experiment. The entire search space in the relevant gene was explored.


585 posted on 07/06/2006 9:12:09 PM PDT by js1138 (Well I say there are some things we don't want to know! Important things!")
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To: js1138; Right Wing Professor
"How many base pairs in the target gene? 1953"

To cover all possible permutations of 1953 base pairs (of which there are 4: (G, A, T, and C) would require 4^1953. 4 to the 1953rd power.

586 posted on 07/06/2006 9:16:29 PM PDT by Southack (Media Bias means that Castro won't be punished for Cuban war crimes against Black Angolans in Africa)
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To: Southack

You aren't trying all the permutations.


587 posted on 07/06/2006 9:20:22 PM PDT by js1138 (Well I say there are some things we don't want to know! Important things!")
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To: js1138
"Check out the actual article. The entire genome is not relevant to the experiment. The entire search space in the relevant gene was explored."

I read your article. It's a fantastic, promising experiment worthy of scientific praise.

But...

It doesn't support your wild-eyed claim that "There have been very recent experiments in heat resistant bacteria in which every possible point mutation in the relevant genes was observed."

20 million does not equal 4 to the 1953rd power.

588 posted on 07/06/2006 9:22:39 PM PDT by Southack (Media Bias means that Castro won't be punished for Cuban war crimes against Black Angolans in Africa)
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To: Southack

Your math is irrelevant. In any given generation it is only necessary for one point mutation to occur that confers an advantage. You are dealing a new hand in every generation, and you are not testing all the permutations.

It's more like draw poker in which you can keep replacing one card at a time until you get one that improves your hand.


589 posted on 07/06/2006 9:29:12 PM PDT by js1138 (Well I say there are some things we don't want to know! Important things!")
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To: js1138
"Your math is irrelevant."

A telling comment. Expected. Even **predicted** in this very thread when I gave the link to the relevant math.

Heck, you even claimed that my math wasn't taking all permutations into account...but...that was before you figured out that the math disproved your fragile worldview.

Now you have to lash out at math itself (wait, let me guess..."No, just your math, man").

Sigh...so typical.

590 posted on 07/06/2006 9:33:57 PM PDT by Southack (Media Bias means that Castro won't be punished for Cuban war crimes against Black Angolans in Africa)
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To: Southack

Well gee, either your math is irrelevant, or you and Dembski are smarter than nearly all of the scientists who have practiced for the last 200 years.

I'll take my chances. You haven't demonstrated anything on this forum. Evolution does not work by dealing a new hand for every generation. Your permutation math is irrelevant.


591 posted on 07/06/2006 9:40:31 PM PDT by js1138 (Well I say there are some things we don't want to know! Important things!")
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To: js1138
"Your permutation math is irrelevant."

My last permutation calculation above disproves your own claim that all sequencing iterations were observed in one bacteria.

Your claim of irrelevancy is desperate and nonsensical, by the way. The math disproves your own claim...no intellectually honest person could claim such math as "irrelevant."

592 posted on 07/06/2006 9:50:48 PM PDT by Southack (Media Bias means that Castro won't be punished for Cuban war crimes against Black Angolans in Africa)
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To: Southack
My last permutation calculation above disproves your own claim that all sequencing iterations were observed in one bacteria.

Evolution does not proceed by dealing a new hand for every generation.

593 posted on 07/06/2006 9:55:14 PM PDT by js1138 (Well I say there are some things we don't want to know! Important things!")
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To: js1138
"Evolution does not proceed by dealing a new hand for every generation."

Are you forever going to avoid answering if point mutations in genes are random or biased?

594 posted on 07/06/2006 10:14:02 PM PDT by Southack (Media Bias means that Castro won't be punished for Cuban war crimes against Black Angolans in Africa)
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To: js1138
Did you actually expect him to provide anything but more evasions? He's still flailing... :)
595 posted on 07/07/2006 4:51:58 AM PDT by CarolinaGuitarman (Gas up your tanks!!)
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To: Southack

In the actual experiment I cited, every point mutated. It really makes no difference in general. No organism knows in advance what mutation will enhance its reproductive potential.


596 posted on 07/07/2006 6:50:33 AM PDT by js1138 (Well I say there are some things we don't want to know! Important things!")
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To: stands2reason

>>Google? Are you joking? Just give me a source.<<

Are you joking? If you want an internet source, I give you this: Google t-rex and "soft tissue".

You will get a plethora of sources.


Google is an on-line search site. And welcome to the 21st century! ;)


597 posted on 07/07/2006 8:23:33 AM PDT by RobRoy (The Internet is doing to Evolution what it did to Dan Rather. Information is power.)
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To: js1138
"In the actual experiment I cited, every point mutated."

Yes, 1953 points.

But every point didn't mutate in every possible combination (i.e. "all possible permutations") as you claimed...because that would require 4 to the 1953rd power for the number of mutations...a mathematical result vastly greater than the mere 20 million total mutations observed in the experiment that you cited.

Now, are you still going to avoid answering if mutations are random or biased?

598 posted on 07/07/2006 11:30:55 AM PDT by Southack (Media Bias means that Castro won't be punished for Cuban war crimes against Black Angolans in Africa)
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To: Southack
Now, are you still going to avoid answering if mutations are random or biased?

Define "mutation". If it is merely a change in the DNA then most mutation is biased. The probability phase space is very, very lumpy.

599 posted on 07/07/2006 12:19:33 PM PDT by tortoise
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To: RobRoy

I know what Google is. I'm sure I'll get many references.

I want a good reference, not garbage.


600 posted on 07/07/2006 12:39:51 PM PDT by stands2reason (ANAGRAM for the day: Socialist twaddle == Tact is disallowed)
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