30 Mar 05
Originally posted by DarfiusBirds are, in some ways, rather like reptiles. The skeleton of birds is similar to that of dinosaurs in the order Saurischia ( diapsid* reptiles that flourished in the Triassic).
I'm confused. Can anyone help me and tell me what birds evolved from?
The heart and blood system closely resembles that of crocodiles, also diapsid reptiles.
It therefore seems likely that birds evolved from this reptile group, although the saurischians are, perhaps, too specialised to be direct ancestors.
For instance, they do not have a clavicle as do birds, and it is probable that birds separated from this, or a similar dinosaur stock, in the Jurassic.
Since their separation, the birds have become adapted to live in almost all parts of the globe.
Birds have been recorded closer to the north, and south, poles than any other large animals.
They can exist at higher altitudes than any other vertebrates, apart from man, and Emperor penguins can apparently dive to 300m below the sea surface without suffering " the bends ".
The ancestry of this most succesful group of vertebrates is uncertain, because so few fossil birds have been preserved.
http://www-biol.paisley.ac.uk/courses/Tatner/biomedia/units/bird3.htm
30 Mar 05
2 edits
Originally posted by WulebgrIn the February 1998 issue of Scientific American, Kevin Padian and Luis Chiappe, while fully backing the dinosaurian origin of birds, added a sidebar explaining the major points of contention:
Birds are, in some ways, rather like reptiles. The skeleton of birds is similar to that of dinosaurs in the order Saurischia ( diapsid* reptiles that flourished in the Triassic).
The heart and blood system closely resembles that of croc ...[text shortened]... p://www-biol.paisley.ac.uk/courses/Tatner/biomedia/units/bird3.htm
1. The hands of theropod dinosaurs and birds differ in important ways.
2. Theropod wishbones differ significantly from those of birds.
3. Avian lungs are very complex and could not have evolved from theropod dinosaur lungs.
4. Theropod dinosaurs appear to have been exclusively ground dwellers; thus, flight would have had to originate from the cursorial or “ground-up” theory, which many scientists do not accept (Padian and Chiappe, 1998).
http://www.apologeticspress.org/modules.php?name=Read&cat=1&itemid=471
Also, Archaeopteryx was around fully formed before most of the theropods existed.
30 Mar 05
Originally posted by DarfiusBirds originated from Dinosaurs.
I'm confused. Can anyone help me and tell me what birds evolved from?
Just look at their feet. The way their heads move.
Does that remind you of something lizardy?
Look at their bodies in proportion to their heads.
Is that mammal or something else?
Look at their wings. Leonardo studied their wings and nearly came up with a helicopter. I've studied their wings and come up with a cocktail!
The wings must be very special!
Listen to their yapping. Isn't that just like something out of Jurassic park?
30 Mar 05
Originally posted by shavixmir
Birds originated from Dinosaurs.
Just look at their feet. The way their heads move.
Does that remind you of something lizardy?
Look at their bodies in proportion to their heads.
Is that mammal or something else?
Listen to their yapping. Isn't that just like something out of Jurassic park?
Sack. Can't argue with that logic. Should give that one a rec.
Happy now Darf ?
PS: The biggest bone of contention re: avain evolution is the evolution of the brain. To take into accounts so many variables and control flight requires indeed a significantly evolved brain.
pc
30 Mar 05
Originally posted by pcaspianNo it doesn't.
Originally posted by shavixmir
[b]Birds originated from Dinosaurs.
Just look at their feet. The way their heads move.
Does that remind you of something lizardy?
Look at their bodies in proportion to their heads.
Is that mammal or something else?
Listen to their yapping. Isn't that just like something out of Jurassic park?
Sack. ...[text shortened]... s so many variables and control flight requires indeed a significantly evolved brain.
pc
[/b]
That's rubbish.
Look at the brain size of a bird or a bat and compare that to a human, a fish, a walrus or a giraffe.
See.
30 Mar 05
Birds are derived from the female human being. The word bird is slightly derogatory. They are sometimes refered to as ladettes. A true bird will drink like a fish and often sleep with you - if she doesn't vomit first. A bird has lots of male friends but is as bad as holding down a long term relationship as they are at keeping down their Smirnoff Ice.
30 Mar 05
Originally posted by invigorateBetter yet:
Birds are derived from the female human being. The word bird is slightly derogatory. They are sometimes refered to as ladettes. A true bird will drink like a fish and often sleep with you - if she doesn't vomit first. A bird has lots of male friends but is as bad as holding down a long term relationship as they are at keeping down their Smirnoff Ice.
1:20 And God said, Let the waters bring forth abundantly the moving creature that hath life, and fowl that may fly above the earth in the open firmament of heaven. 1:21 And God created great whales, and every living creature that moveth, which the waters brought forth abundantly, after their kind, and every winged fowl after his kind: and God saw that it was good. 1:22 And God blessed them, saying, Be fruitful, and multiply, and fill the waters in the seas, and let fowl multiply in the earth. 1:23 And the evening and the morning were the fifth day.
31 Mar 05
Originally posted by DarfiusA model of scholarship:
In the February 1998 issue of Scientific American [snip]
http://www.apologeticspress.org/modules.php?name=Read&cat=1&itemid=471
refer to a respected popular scientific journal, but cite a disreputable website.
It appears logical to conclude that you have not read the Scientific American article to which you refer.
31 Mar 05
Originally posted by WulebgrAre you claiming that those facts aren't true because they come from a Christian source?
A model of scholarship:
refer to a respected popular scientific journal, but cite a disreputable website.
It appears logical to conclude that you have not read the Scientific American article to which you refer.
31 Mar 05
Originally posted by DarfiusI'm claiming that they are unworthy of investigation because there is no evidence of scholarship. It's a nice strategy to keep your opponents chasing smoke and mirrors (I use it it lightning chess), but I don't need to fall for it.
Are you claiming that those facts aren't true because they come from a Christian source?
The disreputable scholarly methods of Brad Harrub and Bert Thompson are well documented. Hence, I call your source "disreputable," and I allege that you have not read the Scientific American article to which you referred.
That the source is "Christian" is irrelevant; that the site is devoted to the movement against science by Fundamentalists does reveal an important aspect of its scientific principles.
31 Mar 05
Originally posted by WulebgrAre you claiming that the hands of theropod dinosaurs and birds do NOT differ in important ways?
I'm claiming that they are unworthy of investigation because there is no evidence of scholarship. It's a nice strategy to keep your opponents chasing smoke and mirrors (I use it it lightning chess), but I don't need to fall for it.
The disreputable scholarly methods of Brad Harrub and Bert Thompson are well documented. Hence, I call your source "disre ...[text shortened]... against science by Fundamentalists does reveal an important aspect of its scientific principles.
Or that theropod wishbones do NOT differ significantly from those of birds?
Or that avian lungs aren't very complex and could have evolved from theropod dinosaur lungs?
Or that this is wrong?
Theropod dinosaurs appear to have been exclusively ground dwellers; thus, flight would have had to originate from the cursorial or “ground-up” theory, which many scientists do not accept (Padian and Chiappe, 1998).
Attack the facts (with proof), not the source.
31 Mar 05
Originally posted by DarfiusI'm claiming, that for people who want to spend their time debating such matters, they should read good science. I'm also asserting that your non-scholarly method illuminates your tactics: you found an interesting quote at an anti-scientific website, threw out a question designed to hook responders, then hit the first response with your chosen quote.
Are you claiming that the hands of theropod dinosaurs and birds do NOT differ in important ways?
Attack the facts (with proof), not the source.
Here's a scientific article that addresses one of your objections:
http://www.pnas.org/cgi/content/full/96/9/5111
Read it.
31 Mar 05
1 edit
Originally posted by DarfiusI don't know what species birds evolved from. You have good points here. They aren't in any way conclusive, but they are interesting.
In the February 1998 issue of Scientific American, Kevin Padian and Luis Chiappe, while fully backing the dinosaurian origin of birds, added a sidebar explaining the major points of contention:
1. The hands of theropod dinosaurs and b ...[text shortened]... [/i] was around fully formed before most of the theropods existed.
I'd like to clarify something:
1. The hands of theropod dinosaurs and birds differ in important ways.
2. Theropod wishbones differ significantly from those of birds.
3. Avian lungs are very complex and could not have evolved from theropod dinosaur lungs.
4. Theropod dinosaurs appear to have been exclusively ground dwellers; thus, flight would have had to originate from the cursorial or “ground-up” theory, which many scientists do not accept (Padian and Chiappe, 1998).
Are you claming that these were the exact words written by Padian and Chiappe and published in a Scientific American article? I have my doubts that anyone could on the one hand claim avian lungs could not possibly evolve from therapod dinosaur lungs and still back up "the dinosaurian origin of birds" unless they felt some other variety of dinosaur was the ancestor.
I've found some online papers that discuss this issue for anyone who's interested:
http://cas.bellarmine.edu/tietjen/images/lung_structure_and_ventilation_i.htm
http://www.devbio.com/article.php?ch=16&id=161