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Author Topic:   What drove bird evolution?
redwolf
Member (Idle past 5104 days)
Posts: 185
From: alexandria va usa
Joined: 04-13-2004


Message 76 of 145 (124791)
07-15-2004 5:49 PM
Reply to: Message 75 by Loudmouth
07-15-2004 4:34 PM


Re: Heaviest flying bird
It's another square/cube thing. Weight is proportional to volume which is a cubed figure, while the ability to fly is ultimately ralated to surface area of wings, which is a squared figure.

This message is a reply to:
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Replies to this message:
 Message 78 by Melchior, posted 07-15-2004 10:27 PM redwolf has replied
 Message 82 by Steen, posted 07-16-2004 12:31 AM redwolf has replied

  
biochem_geek
Inactive Junior Member


Message 77 of 145 (124842)
07-15-2004 10:15 PM
Reply to: Message 66 by redwolf
07-15-2004 2:19 PM


Re: genetic engineering
quote:
Recent studies in fact indicate that humans appear to have been fabricated using the same techniques which we ourselves are now starting to use in bio-engineering projects, which are anything but natural

I think enough other people have explained that there is nothing "unnatural" about horizontally transferred genes. What they haven't mentioned is there probably aren't any in the human genome. Six months after the paper suggesting hundreds of such genes you get this:


Phylogenetic analyses do not support horizontal gene transfers from bacteria to vertebrates
MICHAEL J. STANHOPE, ANDREI LUPAS, MICHAEL J. ITALIA, KRISTIN K. KORETKE, CRAIG VOLKER & JAMES R. BROWN
Nature 411, 940-944 (21 June 2001)

And as we sequence more and more eukaryote genomes it is becoming clear that the genes that Venter et al claimed only had ortohlogs in bacterial genomes are actually more closely related to eukaryotic sequences.


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Melchior
Inactive Member


Message 78 of 145 (124843)
07-15-2004 10:27 PM
Reply to: Message 76 by redwolf
07-15-2004 5:49 PM


Re: Heaviest flying bird
Why don't we use the numbers present in the article you posted a scan of? Or are you doubting the accuracy of them?

Given that the eagle has a wingspan of 8 and the Teratorn has a wingspan of 25, it would have (25/8)^2 = 9.7 times the surface area. Okay so far?

A male bald eagle weights about 13 pounds while a Teratorn weights 170. This is 170/13 = 13 times the weight.

So, either some numbers are wrong in the article, or those guidelines won't apply here. Did the Teratorn really need wings that are trice as thick? Did it need a middle body that is much larger to eat whatever it preyed on?

This message has been edited by Melchior, 07-15-2004 09:34 PM


This message is a reply to:
 Message 76 by redwolf, posted 07-15-2004 5:49 PM redwolf has replied

Replies to this message:
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redwolf
Member (Idle past 5104 days)
Posts: 185
From: alexandria va usa
Joined: 04-13-2004


Message 79 of 145 (124870)
07-15-2004 11:41 PM
Reply to: Message 78 by Melchior
07-15-2004 10:27 PM


Re: Heaviest flying bird
Adrien Desmond put it this way:

quote:

"It would be a grave understatement to say that, as a flying creature, Pteranodon was large. Indeed, there were sound reasons for believing that it was the largest animal that ever could become airborne. With each increase in size, and therefore also weight, a flying animal needs a concomitant increase in power (to beat the wings in a flapper and to hold and maneuver them in a glider), but power is supplied by muscles which themselves add still more weight to the structure.-- The larger a flyer becomes the disproportionately weightier it grows by the addition of its own power supply. There comes a point when the weight is just too great to permit the machine to remain airborne. Calculations bearing on size and power suggested that the maximum weight that a flying vertebrate can attain is about 50 lb.: Pteranodon and its slightly larger but lesser known Jordanian ally Titanopteryx were therefore thought to be the largest flying animals."

The "were thought to be" was, of course, before things like the argentinian teratorn and the Big Bend pterosaurs were discovered.


This message is a reply to:
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biochem_geek
Inactive Junior Member


Message 80 of 145 (124875)
07-16-2004 12:00 AM
Reply to: Message 60 by redwolf
07-15-2004 11:54 AM


quote:

http://www.bearfabrique.org/evorants/bioEngineering.html

Amusingly the article you linked do actually gives you a clue about how evolution has probably worked on the vertebrates.

quote:

from the article
The human genome probably does not contain significantly more genes than the fugu fish

Not only are there not very many more genes, they all pretty much the same. If we are being rational that’s 400 million years of evolution and almost exactly the same repertoire of genes yet one is a small, inflatable fish that may be able to make people into zombies and the other is you. The difference between different vertebrates isn’t by and large the presence or lack of genes in their genome but the way in which they are “used.” Genes are turned on for longer in development, or alternative splicings are used to generate new functionalities on “old” proteins and probably most importantly new tissue specific regulation of genes arises by the addition of new promoters.

Here is a recently observed example of exactly that

Before you go off on the “well that’s just de-evolution of an ancestral type” here is an example of a mobile element providing a new promoter to an existing gene and generating new tissue specific regulation in primates

Mobile element insertion can also lead to tissue specific expression of genes. One striking instance of this has recently been revealed. CYP19 is a gene that encodes aromataseP450, an important enzyme in the biosynthesis of estrogen; it is expressed primarily in the gonads and brain of most mammals. In the primates it is also expressed to high levels in the placenta, this expression is driven by a promoter located 100kb upstream of the gene. This alternative promoter has been shown to be the result of a mobile element insertion that happened early in the evolution of primates providing a new way of controlling estrogen levels during pregnancy. The authors of the paper that revealed this fact have described another 15 genes they believe to be alternatively promoted in specific tissue due to a mobile elements insertion proving a new promoter.( Reference )

Now I realize it seems that I’ve got way off topic but I assure you it is not so. Your main argument against the evolution of birds is from personal incredulity, “evolving something this different isn’t possible.” Other people have eloquently argued that flying could start without the highly intricate systems we see in birds today and how once flying got its start there would be very strong pressure to get better at it and really dominate the new niche. What I’m trying to add is that wings, and lungs and hearts and brains aren’t mutating the genes are. And its becoming more and more clear that very small mutations; moving a splice site, down regulating expression of a gene by adding polyA sequence in an intron or the incorporation of a new promoter from a mobile element is enough to generate major morphological change.

If birds had really been "engineered" surely the creator would start again. To borrow an analogy from Dawkins the first jet engines weren't developed by bashing around prop' driven plane's engines, or just lengthening bolts of panels or cobbling together different parts of the original engine to create new functions. But that is how we, and fugu and birds work.

This message has been edited by biochem_geek, 07-16-2004 05:27 AM


This message is a reply to:
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Steen
Inactive Member


Message 81 of 145 (124880)
07-16-2004 12:19 AM
Reply to: Message 64 by redwolf
07-15-2004 2:13 PM


Re: I own chickens, Redwolf
What nonsense. Lots of birds are more flightless than chickens, because they had no predators that they could escape through flight. The chickens, evolving under protective situations, artificially selected for traits other than flights are perfectly OK with poor flight.

You are as bad as desotobul on the delphi forums.


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Steen
Inactive Member


Message 82 of 145 (124883)
07-16-2004 12:31 AM
Reply to: Message 76 by redwolf
07-15-2004 5:49 PM


Re: Heaviest flying bird
quote:
It's another square/cube thing. Weight is proportional to volume which is a cubed figure, while the ability to fly is ultimately ralated to surface area of wings, which is a squared figure.
Which would only be true if the ancient bird was directly proportional to the bird used for comparison.

So not alone are you very ignorant of Evolution; rather simple physics concepts also escapes you. Should I conclude that you really don't know ANY science?


This message is a reply to:
 Message 76 by redwolf, posted 07-15-2004 5:49 PM redwolf has replied

Replies to this message:
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jar
Member
Posts: 33957
From: Texas!!
Joined: 04-20-2004
Member Rating: 2.2


Message 83 of 145 (124888)
07-16-2004 12:46 AM
Reply to: Message 82 by Steen
07-16-2004 12:31 AM


Re: Heaviest flying bird
It's also true that while volume goes up, weight might not. There is a difference between density and weight.


Aslan is not a Tame Lion

This message is a reply to:
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arachnophilia
Member (Idle past 656 days)
Posts: 9069
From: god's waiting room
Joined: 05-21-2004


Message 84 of 145 (124941)
07-16-2004 5:31 AM
Reply to: Message 58 by crashfrog
07-15-2004 11:39 AM


ouy of curiosity, what bird lacks a beak?

Archaeopteryx, of course.

i wasn't even going to bother with that, because it gets debated so often. (and i'd be more willing to call it a dinosaur than a bird, since it lacks several important bird features)

i thought you meant modern birds, and i was just stupid.


This message is a reply to:
 Message 58 by crashfrog, posted 07-15-2004 11:39 AM crashfrog has replied

Replies to this message:
 Message 86 by crashfrog, posted 07-16-2004 6:34 AM arachnophilia has replied

  
arachnophilia
Member (Idle past 656 days)
Posts: 9069
From: god's waiting room
Joined: 05-21-2004


Message 85 of 145 (124942)
07-16-2004 5:36 AM
Reply to: Message 59 by redwolf
07-15-2004 11:50 AM


My own original papers on the topic are at:

http://www.bearfabrique.org/Catastrophism/sauropods/dinosaurs.html

you have a picture of an ica stone on the top of your page. look for the thread on those here... they're known forgeries.

you also have a link to the hava supai pictograph, which looks nothing like any dinosaur that ever lived, but vaguely like an 19th century mangling of an iguanodon skeleton. (all hadrosaurs are quadrapedal. to stand upright, they'd have to break about 4 vertbrae in the lower tail.)

but this bring up an interesting point. from the bones you say that grabity must have been less. well, if this was the case, all other animals present at the time would be subject to same forces. humans would be a lot bigger on average if they lived at the same time.

so pick one. either dinosaurs lived with humans, or gravity was less. one crackpot theory at a time.


This message is a reply to:
 Message 59 by redwolf, posted 07-15-2004 11:50 AM redwolf has replied

Replies to this message:
 Message 88 by redwolf, posted 07-16-2004 8:44 AM arachnophilia has replied
 Message 89 by redwolf, posted 07-16-2004 8:48 AM arachnophilia has replied

  
crashfrog
Member (Idle past 780 days)
Posts: 19762
From: Silver Spring, MD
Joined: 03-20-2003


Message 86 of 145 (124949)
07-16-2004 6:34 AM
Reply to: Message 84 by arachnophilia
07-16-2004 5:31 AM


(and i'd be more willing to call it a dinosaur than a bird, since it lacks several important bird features)

Most of the literature I've read classifies it as bird and not dinosaur, but it's sufficiently transitional that there's no simple way to choose where to put it.

That, of course, is the strongest argument for evolution, and also the strongest argument against Redwolf's position - either Archaeopteryx is a bird who lacks many of the features RW claims birds couldn't survive without, or it's a non-bird with many of the features RW claimed would be survival liabilities in a non-bird.


This message is a reply to:
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arachnophilia
Member (Idle past 656 days)
Posts: 9069
From: god's waiting room
Joined: 05-21-2004


Message 87 of 145 (124950)
07-16-2004 6:41 AM
Reply to: Message 86 by crashfrog
07-16-2004 6:34 AM


exactly.

This message is a reply to:
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redwolf
Member (Idle past 5104 days)
Posts: 185
From: alexandria va usa
Joined: 04-13-2004


Message 88 of 145 (124958)
07-16-2004 8:44 AM
Reply to: Message 85 by arachnophilia
07-16-2004 5:36 AM


ica stones
quote:

you have a picture of an ica stone on the top of your page. look for the thread on those here... they're known forgeries.

The ica stones are not forgeries. The original discovery involved several tens of thousands of the things; nobody ever did that much work on the off chance that gringos might be willing to buy all of them, i.e. on pure speculation. Carving one of those things would take weeks and God knows what it would take to carve one and then try to make it appear ancient as they all do.


This message is a reply to:
 Message 85 by arachnophilia, posted 07-16-2004 5:36 AM arachnophilia has replied

Replies to this message:
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redwolf
Member (Idle past 5104 days)
Posts: 185
From: alexandria va usa
Joined: 04-13-2004


Message 89 of 145 (124959)
07-16-2004 8:48 AM
Reply to: Message 85 by arachnophilia
07-16-2004 5:36 AM


quote:

you also have a link to the hava supai pictograph, which looks nothing like any dinosaur that ever lived, but vaguely like an 19th century mangling of an iguanodon skeleton.

To most people it looks like a sauropod dinosaur. The web site also links to other images of known dinosaur types, such as the sauropod dinosaur at the state park in Utah:

edited to fix page width - The Queen

This message has been edited by AdminAsgara, 07-16-2004 11:17 AM


This message is a reply to:
 Message 85 by arachnophilia, posted 07-16-2004 5:36 AM arachnophilia has replied

Replies to this message:
 Message 104 by arachnophilia, posted 07-16-2004 5:56 PM redwolf has replied

  
redwolf
Member (Idle past 5104 days)
Posts: 185
From: alexandria va usa
Joined: 04-13-2004


Message 90 of 145 (124960)
07-16-2004 8:51 AM
Reply to: Message 82 by Steen
07-16-2004 12:31 AM


Re: Heaviest flying bird
quote:

So not alone are you very ignorant of Evolution; rather simple physics concepts also escapes you. Should I conclude that you really don't know ANY science?

Don't act surprised when you find your comments being ignored...


This message is a reply to:
 Message 82 by Steen, posted 07-16-2004 12:31 AM Steen has replied

Replies to this message:
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