Understanding through Discussion


Welcome! You are not logged in. [ Login ]
EvC Forum active members: 64 (9038 total)
218 online now:
kjsimons, Phat (AdminPhat) (2 members, 216 visitors)
Newest Member: Barry Deaborough
Post Volume: Total: 885,690 Year: 3,336/14,102 Month: 277/724 Week: 35/91 Day: 3/17 Hour: 0/0


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
Author Topic:   Birds and Reptiles
Taq
Member (Idle past 1 days)
Posts: 8482
Joined: 03-06-2009


Message 16 of 135 (582500)
09-21-2010 4:57 PM
Reply to: Message 14 by faith24
09-21-2010 4:44 PM


This article seem to say otherwise about dino-bird evolution. Maybe it was the other way around?
http://www.physorg.com/news184959295.html

It is speaking of a single species, microraptor. This doesn't mean that the analysis of this single species applies to ALL dino-bird intermediates.

There are many differences between birds and dinosaurs. Their lungs, reproductive system, etc.

There is strong evidence that non-avian dinosaurs had the same type of lung:

"Evidence for Avian Intrathoracic Air Sacs in a New Predatory Dinosaur from Argentina"

ABE: tried to add the link to the source, but it gets messed up by the board software somehow. A google search for the title should point you to the original source material.

Edited by Taq, : No reason given.

Edited by Taq, : No reason given.

Edited by Taq, : No reason given.


This message is a reply to:
 Message 14 by faith24, posted 09-21-2010 4:44 PM faith24 has not yet responded

Replies to this message:
 Message 33 by arachnophilia, posted 12-29-2010 4:23 AM Taq has not yet responded

  
PaulK
Member
Posts: 16861
Joined: 01-10-2003
Member Rating: 4.0


Message 17 of 135 (582503)
09-21-2010 5:21 PM
Reply to: Message 14 by faith24
09-21-2010 4:44 PM


There are some questions about that paper.

Here is what paleozoologist Darren Naish has to say.

HE has quite a few criticisms of the arguments, and notes that the claims about bird ancestry don't even appear in the paper - bur are in the press releases. Which rather sounds like an attempt to hype up a paper that isn't really strong enough to back up the claims made to the press.


This message is a reply to:
 Message 14 by faith24, posted 09-21-2010 4:44 PM faith24 has not yet responded

  
Dr Adequate
Member
Posts: 16112
Joined: 07-20-2006


Message 18 of 135 (582522)
09-21-2010 7:07 PM
Reply to: Message 14 by faith24
09-21-2010 4:44 PM


The study that your article refers to is that of Ruben and Quick:

But they also write:

Many of these skeletal specializations are not apparent in the earliest birds, including Archaeopteryx, confuciusornithine or enantiornithine birds (Hillenius and Ruben, 2004a). Their presence is also questionable in even Early Cretaceous ornithurines but well developed in the Late Cretaceous hesperornithiform birds (Hillenius and Ruben, 2004a). The femur most likely did not attain its subhorizontal position until the Late Cretaceous in ornithurines as indicated by the presence of the antitrochanter...

So according to the very scientists you're referencing, Archaeopteryx did not have a fixed femur. But it did have feathers and wings.

---

I should like to add --- don't ever look to journalists to tell you the state of play about evolution.

About any interesting fossil, they will tell you one of two things.

Either they will tell you:

(a) This is the final piece in the jigsaw that proves that evolution is true.

or ---

(b) This is a weird anomaly that turns the whole theory of evolution on its head.

And whichever one of those two things they say, they always turn out to be wrong. Journalists always over-sensationalize everything they write.

Edited by Dr Adequate, : No reason given.


This message is a reply to:
 Message 14 by faith24, posted 09-21-2010 4:44 PM faith24 has not yet responded

Replies to this message:
 Message 19 by frako, posted 09-22-2010 11:21 AM Dr Adequate has not yet responded

  
frako
Member
Posts: 2931
From: slovenija
Joined: 09-04-2010


Message 19 of 135 (582618)
09-22-2010 11:21 AM
Reply to: Message 18 by Dr Adequate
09-21-2010 7:07 PM


they kinda have to to sell their newspaper

a title like new fossil found kinda does not get the attention that they want


This message is a reply to:
 Message 18 by Dr Adequate, posted 09-21-2010 7:07 PM Dr Adequate has not yet responded

  
faith24
Junior Member (Idle past 2346 days)
Posts: 27
Joined: 09-10-2010


(1)
Message 20 of 135 (582877)
09-23-2010 6:17 PM
Reply to: Message 15 by jar
09-21-2010 4:55 PM


quote:
Actually that doesn't say that birds came before dinos or that dinosaurs evolved from birds, just that the split may well have been earlier and some of the finds may have been misidentified.

This is another example of why Science will work. As more information is learned, even strongly held opinions get challenged.


You know, people always thought that birds evolved from dinosaurs. That's why we got the idea "then how come there are still birds"? So now, they changed it and say that they share a common ancestor. So the ancestor between modern birds and dinosaurs is the Archeopteryx right?

Some suggest that the Archeopteryx is just a perching bird. There are huge differences between birds and dinosaurs that it is impossible for birds to evolved from dinosaurs. The idea is so confusing even after looking on the subject for a while now i'm still confused because there are a lot of misinformation out there you don;t know which one to believe.

What do you think about these birds foot print?

http://www.geotimes.org/june02/WebExtra0627.html


This message is a reply to:
 Message 15 by jar, posted 09-21-2010 4:55 PM jar has responded

Replies to this message:
 Message 21 by Dr Adequate, posted 09-23-2010 6:28 PM faith24 has responded
 Message 23 by jar, posted 09-23-2010 7:52 PM faith24 has not yet responded
 Message 32 by arachnophilia, posted 12-29-2010 4:03 AM faith24 has not yet responded
 Message 34 by New Cat's Eye, posted 12-29-2010 10:58 AM faith24 has not yet responded

  
Dr Adequate
Member
Posts: 16112
Joined: 07-20-2006


Message 21 of 135 (582881)
09-23-2010 6:28 PM
Reply to: Message 20 by faith24
09-23-2010 6:17 PM


You know, people always thought that birds evolved from dinosaurs. That's why we got the idea "then how come there are still birds"? So now, they changed it and say that they share a common ancestor.

No they didn't.

So the ancestor between modern birds and dinosaurs is the Archeopteryx right?

No.

Some suggest that the Archeopteryx is just a perching bird.

Yes, by definition it's a bird. But "just" a bird? No.

There are huge differences between birds and dinosaurs that it is impossible for birds to evolved from dinosaurs.

Perhaps you could mention some of these "huge differences" and demonstrate the impossibility.

Or perhaps you prefer to indulge in vacuous rhetoric.

The idea is so confusing even after looking on the subject for a while now i'm still confused because there are a lot of misinformation out there you don;t know which one to believe.

If you have really been "looking at the subject for a while", how is it possible for you to write nonsense like this? ---

You know, people always thought that birds evolved from dinosaurs. That's why we got the idea "then how come there are still birds"? So now, they changed it and say that they share a common ancestor. So the ancestor between modern birds and dinosaurs is the Archeopteryx right?

You evidently haven't even bothered to learn the ABC of the subject.

Edited by Dr Adequate, : No reason given.


This message is a reply to:
 Message 20 by faith24, posted 09-23-2010 6:17 PM faith24 has responded

Replies to this message:
 Message 22 by faith24, posted 09-23-2010 6:49 PM Dr Adequate has responded

  
faith24
Junior Member (Idle past 2346 days)
Posts: 27
Joined: 09-10-2010


(1)
Message 22 of 135 (582888)
09-23-2010 6:49 PM
Reply to: Message 21 by Dr Adequate
09-23-2010 6:28 PM


quote:
No they didn't.

So if birds didn't evolved from the dinosaurs, then birds have their own lineage apart from dinosaurs. So then evolution would say that they both share a common ancestor. So how did people came up with the idea that birds evolved from dinosaurs? That must be a misconception of what evolution says then.

quote:
No.

Who are the ancestors? I'd like to know.

quote:
Yes, by definition it's a bird. But "just" a bird? No.

How do you tell if it's a bird or not?

quote:
Perhaps you could mention some of these "huge differences" and demonstrate the impossibility.

Or perhaps you prefer to indulge in vacuous rhetoric.


Birds cannot move their thigh bone so they must bend their knee while walking or running. Land creatures such as the theropods can move their thigh bone. Also birds required more oxygen than cold blooded animals and so to supply this need, birds have special lungs and supporting musculature. If birds have the same muscle structure as the dinosaurs and could move their thigh, their lungs would collapsed.

quote:
If you have really been "looking at the subject for a while", how is it possible for you to write nonsense like this? ---

Because people are saying different things.

Edited by faith24, : No reason given.

Edited by faith24, : No reason given.


This message is a reply to:
 Message 21 by Dr Adequate, posted 09-23-2010 6:28 PM Dr Adequate has responded

Replies to this message:
 Message 24 by Dr Adequate, posted 09-23-2010 8:05 PM faith24 has not yet responded
 Message 25 by Blue Jay, posted 09-23-2010 8:53 PM faith24 has not yet responded
 Message 27 by caffeine, posted 09-24-2010 4:30 AM faith24 has not yet responded
 Message 31 by arachnophilia, posted 12-29-2010 3:36 AM faith24 has not yet responded

  
jar
Member
Posts: 33343
From: Texas!!
Joined: 04-20-2004
Member Rating: 3.2


Message 23 of 135 (582898)
09-23-2010 7:52 PM
Reply to: Message 20 by faith24
09-23-2010 6:17 PM


You know, people always thought that birds evolved from dinosaurs. That's why we got the idea "then how come there are still birds"? So now, they changed it and say that they share a common ancestor. So the ancestor between modern birds and dinosaurs is the Archeopteryx right?

No, not exactly. And no, it is unlikely that Archeopteryx is the common ancestor between birds and dinos.

And I have no opinion yet on those footprints. As the article you linked to says, "Melchor and team indicate that there are some features that do not correspond to bird morphology, but these are few. One example is the presence of pad impressions in some of the footprints. Other features that might be bird-like, but could be common to other theropods include the wide angles between the second and fourth digits."

It is simply too early say what the footprints mean.


Anyone so limited that they can only spell a word one way is severely handicapped!

This message is a reply to:
 Message 20 by faith24, posted 09-23-2010 6:17 PM faith24 has not yet responded

  
Dr Adequate
Member
Posts: 16112
Joined: 07-20-2006


Message 24 of 135 (582901)
09-23-2010 8:05 PM
Reply to: Message 22 by faith24
09-23-2010 6:49 PM


So if birds didn't evolved from the dinosaurs, then birds have their own lineage apart from dinosaurs. So then evolution would say that they both share a common ancestor. So how did people came up with the idea that birds evolved from dinosaurs? That must be a misconception of what evolution says then.

You certainly seem to be laboring under some kind of misconception. But your writing is not clear enough for me to find out what it is.

Who are the ancestors? I'd like to know.

Dinosaurs, apparently.

How do you tell if it's a bird or not?

I told you --- birds are defined as being Archaeopterx and anything more like a modern bird than it is.

Birds cannot move their thigh bone so they must bend their knee while walking or running. Land creatures such as the theropods can move their thigh bone. Also birds required more oxygen than cold blooded animals and so to supply this need, birds have special lungs and supporting musculature. If birds have the same muscle structure as the dinosaurs and could move their thigh, their lungs would collapsed.

As you have already been informed, Archaeopteryx has the same sort of legs as dinosaurs. And Archeopteryx is a bird. So this can't be a "huge difference" between dinosaurs and birds. It would have to be a "huge difference" between birds and ... other birds.

I notice you forgot to demonstrate the impossibility of one sort of leg evolving from another. Presumably because you can't.

Because people are saying different things.

That's because some people are idiots.

This is why you should get your information on fossils from paleontologists rather than from people who make stuff up.

Edited by Dr Adequate, : No reason given.


This message is a reply to:
 Message 22 by faith24, posted 09-23-2010 6:49 PM faith24 has not yet responded

  
Blue Jay
Member (Idle past 1599 days)
Posts: 2843
From: You couldn't pronounce it with your mouthparts
Joined: 02-04-2008


Message 25 of 135 (582911)
09-23-2010 8:53 PM
Reply to: Message 22 by faith24
09-23-2010 6:49 PM


Hi, Faith24.

faith24 writes:

So if birds didn't evolved from the dinosaurs, then birds have their own lineage apart from dinosaurs. So then evolution would say that they both share a common ancestor. So how did people came up with the idea that birds evolved from dinosaurs? That must be a misconception of what evolution says then.

First off, the theory of evolution doesn’t say either way. Neither of the two options are a violation of the theory of evolution, because the theory of evolution is about how evolution happens, not about what sequence of events happened.

As an example, compare it to the “theory” of combustion, which describes how a gas-powered engine propels a vehicle. This theory says nothing about where the vehicle powered by combustion goes. All it says is how the engine works, not what is accomplished with it.

The Theory of Evolution is just the description of how the evolutionary “engine” works. Birds evolving from dinosaurs or birds evolving from some other group is just a description of where the evolutionary “vehicle” took the lineage using that “engine.”

If dinosaurs did not evolve from birds, then this is a misconception of the evidence, not a misconception of the theory.

-----

faith24 writes:

How do you tell if it's a bird or not?

That’s the question, isn’t it?

The line between what is a bird and what is a dinosaur is not distinct, so, in many cases, you can’t tell if it’s a bird or not.

-----

faith24 writes:

Birds cannot move their thigh bone so they must bend their knee while walking or running.

First, in case you didn’t notice, you have to bend your knees while walking or running, too.

Second, not all birds have fixed thigh bone. Ostriches do not have fixed thigh bones, yet ostriches breathe like birds, and all indications are that ostriches breathe just fine.


-Bluejay (a.k.a. Mantis, Thylacosmilus)

Darwin loves you.


This message is a reply to:
 Message 22 by faith24, posted 09-23-2010 6:49 PM faith24 has not yet responded

  
Strongbow
Junior Member (Idle past 3811 days)
Posts: 26
Joined: 09-16-2010


Message 26 of 135 (582918)
09-23-2010 9:15 PM


Faith... you have clearly not read the refernced papers here. If you had, you'd have noticed some points:

1) Archaeoptyrex was long thought to have an "opposing claw" like modern birds, but all the fossils then found had distorted feet that made it appear that way. Recently a fossil of Arch was found WITHOUT distorted feet, and it does NOT have an opposing claw. It had a foot just like dinosaurs.

2) If you'd have read the blog that criticized the paper (posted by PaulK) you seem to refer to, you'd have seen that not all modern birds have relatively immobile thighs (an ostrich is an example of a modern biord with a m obile thigh) and that it has not been established that an immobile thigh is necessary to repirate with abdominal airsacs... in fact, the evidence is to the contrary (edit: I see Bluejay pointed this out... sorry for the dogpile).

Edited by Strongbow, : No reason given.

Edited by Strongbow, : No reason given.

Edited by Strongbow, : No reason given.


  
caffeine
Member
Posts: 1800
From: Prague, Czech Republic
Joined: 10-22-2008


Message 27 of 135 (582984)
09-24-2010 4:30 AM
Reply to: Message 22 by faith24
09-23-2010 6:49 PM


So if birds didn't evolved from the dinosaurs, then birds have their own lineage apart from dinosaurs. So then evolution would say that they both share a common ancestor. So how did people came up with the idea that birds evolved from dinosaurs? That must be a misconception of what evolution says then.

People came up with the idea that birds evolved from dinosaurs because of the many features that birds share with dinosaurs, specifically with a particular group of dinosaurs, the theropods. Like theropods, birds support most of their weight on just three toes while standing on the ground, with the first toe reversed to point backwards. Particular groups of theropods share more with birds than others - the ischium (part of the hip) is shorter than other theropods, they lose some of the digits on their hand, and the collar bone is fused with the interclavicle - a diamond shaped bone at its base.

These are a few big examples that I've listed, but the complete list of shared features between the skeletons of birds and theropods is long and detailed. It's true that there are still a few palaeontologists who argue that birds aren't theropods, but their position is becoming less supportable the more that's discovered - for example the indisputable prescence of vaned feathers in some theropods, and what might be proto-feathers in other theropods thought to be less closely related to birds.


This message is a reply to:
 Message 22 by faith24, posted 09-23-2010 6:49 PM faith24 has not yet responded

Replies to this message:
 Message 38 by Buzsaw, posted 12-31-2010 9:07 AM caffeine has not yet responded

  
wolfwing
Junior Member (Idle past 3719 days)
Posts: 9
Joined: 12-27-2010


Message 28 of 135 (598179)
12-29-2010 12:00 AM
Reply to: Message 14 by faith24
09-21-2010 4:44 PM


there are some things that do tie birds to dinosaurs. Best possible example, though havn't read up on if they fully checked it out, but B.Rex, the famous "soft"tissue T.rex had in the bones structures that looked alot like the structures that birds form within their bones when they are pregnant and about to lay eggs.

This message is a reply to:
 Message 14 by faith24, posted 09-21-2010 4:44 PM faith24 has not yet responded

  
Tupinambis
Junior Member (Idle past 3556 days)
Posts: 18
Joined: 12-12-2010


Message 29 of 135 (598181)
12-29-2010 12:40 AM


Arbitrary differences
In regards to the definition of what a "bird" is, I'm just going to throw this out here. There were some rumblings not too long ago (a few years) about the idea of incorporating all of the birds into the reptile group, or folding the crocodilians and birds together into an archosaur group. Either way "Aves" would effectively cease to be its own MAJOR taxonomic group (more like "Squamata" within the group "Reptilia"). The ornithology professors flipped shits when they first heard of that though.

I personally support making a separate archosaur group since birds and crocodiles really aren't all that different: no less different than a whale, a bat and [maybe] a platypus yet they're classified together. IMO the current definition of a "bird' that separates them from other reptiles is extremely tenuous: Beaks, feathers, warm-blooded, and can fly. Turtles have beaks, Bats can fly, Great White Sharks are warm blooded, and feathers are really just fluffy scales.

What was that about being off topic? Oops. As for the OP: Birds almost certainly evolved from a type of small dinosaur; if not then at the very least they shared a very close common ancestor.

Edited by Tupinambis, : No reason given.


Replies to this message:
 Message 30 by arachnophilia, posted 12-29-2010 1:44 AM Tupinambis has not yet responded

  
arachnophilia
Member (Idle past 245 days)
Posts: 9069
From: god's waiting room
Joined: 05-21-2004


Message 30 of 135 (598183)
12-29-2010 1:44 AM
Reply to: Message 29 by Tupinambis
12-29-2010 12:40 AM


Re: Arbitrary differences
tegu writes:

In regards to the definition of what a "bird" is, I'm just going to throw this out here. There were some rumblings not too long ago (a few years) about the idea of incorporating all of the birds into the reptile group, or folding the crocodilians and birds together into an archosaur group. Either way "Aves" would effectively cease to be its own MAJOR taxonomic group (more like "Squamata" within the group "Reptilia"). The ornithology professors flipped shits when they first heard of that though.

this is more than rumblings; it is now the majority viewpoint among paleontologists, and most biologists. ornithologists didn't particularly like it, at first, but the (vocal) opponents of "birds are dinosaurs" are a small minority in the ornithology community.

I personally support making a separate archosaur group since birds and crocodiles really aren't all that different

the issue is not really one of difference or similarity, but of heredity. all the evidence points to aves being a subclade of dinosauria, not a sister clade.

you might be able to find some information here or here.


אָרַח

This message is a reply to:
 Message 29 by Tupinambis, posted 12-29-2010 12:40 AM Tupinambis has not yet responded

  
Newer Topic | Older Topic
Jump to:


Copyright 2001-2018 by EvC Forum, All Rights Reserved

™ Version 4.0 Beta
Innovative software from Qwixotic © 2021