Register | Sign In


Understanding through Discussion


EvC Forum active members: 65 (9162 total)
3 online now:
Newest Member: popoi
Post Volume: Total: 915,806 Year: 3,063/9,624 Month: 908/1,588 Week: 91/223 Day: 2/17 Hour: 0/0


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
Author Topic:   Theropods and Birds showing a change in kinds
New Cat's Eye
Inactive Member


Message 1 of 150 (541808)
01-06-2010 12:39 PM


Creationists and IDists have asked for examples of one kind evolving into another and this is my attempt to share with them what I've found convincing of just that.
I went to a local park a while back and they had a little animal exibit with a petting zoo. In one of their cages they have an emu. I was standing on the other side of the fence looking this thing in the eyes and I couldn't help but notice that it did look like a dinosaur. I was messing with it a bit and the darn thing hissed at me!*(see below) It sounded just like a lizard. Then I looked at its feet and they really looked like some scaly-lizard dinosaur feet. And when you look at the whole animal, it is very similiar to a theropod dinosaur in shape.
Let's look at some pictures:
Here is a theropod:
Here is an ostrich (its close to an emu):
At first glance it should be obvious that these animals are two different kinds, but let's look closer.
Here's some skeletons:
I think they look similiar enough that you could get one from the other with microevolutionary changes. Their general 'body plan' is pretty similiar with the two long legs and small arms, kinda hunched over with a head on a long neck.
And look how similiar their feet are:
The emu feet still have scales on them!
And it doesn't take much imagination to see how feathers could be elongated and modified scales.
All these slight differences, or similarities, could easily be microevolutionary changes form to the other. But when we look at them as a whole, or in general, we see that they are different kinds.
I'm trying to be very general here and am not implying that ostriches are direct decendents of velociraptors, but I think its obvious that birds did decend from theropods. And that its a great example of one kind becomming another.
*here's the best youtube video I could find where you could hear an emu hiss. Turn it up and listen at 0:09 - 0:11:
Sounds like a lizard, doesn't it?
So what do you think? Two different kinds where one decended from the other through a bunch of microevolutionary changes.
I found it convincing. Do you?

ABE:
I don't intend this to be much of a scientific discussion, and don't want to get bogged down on defining 'kind', so I'd prefer it not in one of the science forums.
Edited by Catholic Scientist, : see ABE

Replies to this message:
 Message 3 by slevesque, posted 01-07-2010 9:36 AM New Cat's Eye has not replied
 Message 150 by pandion, posted 08-07-2012 12:56 AM New Cat's Eye has not replied

  
Admin
Director
Posts: 12995
From: EvC Forum
Joined: 06-14-2002
Member Rating: 2.3


Message 2 of 150 (541981)
01-07-2010 6:57 AM


Thread Copied from Proposed New Topics Forum
Thread copied here from the Theropods and Birds showing a change in kinds thread in the Proposed New Topics forum.

  
slevesque
Member (Idle past 4640 days)
Posts: 1456
Joined: 05-14-2009


Message 3 of 150 (542015)
01-07-2010 9:36 AM
Reply to: Message 1 by New Cat's Eye
01-06-2010 12:39 PM


Interesing, I have also always thought that this:
Astonishingly looked like this:
I hope you can see my point. Similarity, either in the phenotype or the genotype, does not prove relationship unfortunately. This is why it is more important to look at the differences, and see if an evolutionary mechanism can account going from one state to the other.
The example you talked about with scales and feathers would be one such difference (and a topic of it's own, or we can discuss it here), because maybe I don't have enough imagination, but I don't see a feather as an elongated and modified scale.

This message is a reply to:
 Message 1 by New Cat's Eye, posted 01-06-2010 12:39 PM New Cat's Eye has not replied

Replies to this message:
 Message 4 by Huntard, posted 01-07-2010 9:44 AM slevesque has replied
 Message 5 by Larni, posted 01-07-2010 10:12 AM slevesque has not replied
 Message 14 by Peepul, posted 01-07-2010 12:18 PM slevesque has not replied

  
Huntard
Member (Idle past 2294 days)
Posts: 2870
From: Limburg, The Netherlands
Joined: 09-02-2008


Message 4 of 150 (542018)
01-07-2010 9:44 AM
Reply to: Message 3 by slevesque
01-07-2010 9:36 AM


slevesque writes:
Interesing, I have also always thought that this:
{pic of Darwin}
Astonishingly looked like this:
{Pic of Chimp}
It does, doesn't it.
I hope you can see my point.
That things with similar morphology are related?
Similarity, either in the phenotype or the genotype, does not prove relationship unfortunately.
Oh.... Then why did you pic a human and a chimp, two creatures that are related?

I hunt for the truth
I am the one Orgasmatron, the outstretched grasping hand
My image is of agony, my servants rape the land
Obsequious and arrogant, clandestine and vain
Two thousand years of misery, of torture in my name
Hypocrisy made paramount, paranoia the law
My name is called religion, sadistic, sacred whore.
-Lyrics by Lemmy Kilmister of Motorhead

This message is a reply to:
 Message 3 by slevesque, posted 01-07-2010 9:36 AM slevesque has replied

Replies to this message:
 Message 6 by slevesque, posted 01-07-2010 10:25 AM Huntard has not replied

  
Larni
Member (Idle past 163 days)
Posts: 4000
From: Liverpool
Joined: 09-16-2005


Message 5 of 150 (542026)
01-07-2010 10:12 AM
Reply to: Message 3 by slevesque
01-07-2010 9:36 AM


I'm confused:
In response to two creatures in different kinds being shown to be closely related yo rebut with two creatures in different kinds that have also been shown to be closely related.
What were you thinking?

This message is a reply to:
 Message 3 by slevesque, posted 01-07-2010 9:36 AM slevesque has not replied

  
slevesque
Member (Idle past 4640 days)
Posts: 1456
Joined: 05-14-2009


Message 6 of 150 (542031)
01-07-2010 10:25 AM
Reply to: Message 4 by Huntard
01-07-2010 9:44 AM


It was to show that if the classical example of chimp and human similarities does not convince me of relationship, neither will an emu and a theropod.
CS wants to prove relationship with similarity, but it just isn't enough. It's the classical case of affirming the consequent:
Related species would have similar features
Two species have similar features
therefore they are related
Which is fallacious. Besides, any knowledgeable evolutionists should know this, considering the sizeable amount of convergent evolution examples in my biology book ...

This message is a reply to:
 Message 4 by Huntard, posted 01-07-2010 9:44 AM Huntard has not replied

Replies to this message:
 Message 7 by hooah212002, posted 01-07-2010 10:41 AM slevesque has replied
 Message 8 by Larni, posted 01-07-2010 10:46 AM slevesque has replied
 Message 9 by Dr Adequate, posted 01-07-2010 10:47 AM slevesque has replied
 Message 18 by DC85, posted 01-25-2010 10:16 AM slevesque has not replied

  
hooah212002
Member (Idle past 801 days)
Posts: 3193
Joined: 08-12-2009


Message 7 of 150 (542038)
01-07-2010 10:41 AM
Reply to: Message 6 by slevesque
01-07-2010 10:25 AM


CS wants to prove relationship with similarity, but it just isn't enough.
no, slevesque. CS is not trying to use this as the ONLY evidence. It is being used AS a PIECE of evidence.
Creo's and IDists try this, not scientists (catholic or not, )
there are other pieces of evidence (which have been trudged through all throughout this forum) that ALSO give credence to this similarity.

Who are we? We find that we live on an insignificant planet of a humdrum star lost in a galaxy tucked away in some forgotten corner of a universe in which there are far more galaxies than people
-Carl Sagan
For me, it is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring.
-Carl Sagan

This message is a reply to:
 Message 6 by slevesque, posted 01-07-2010 10:25 AM slevesque has replied

Replies to this message:
 Message 10 by slevesque, posted 01-07-2010 10:53 AM hooah212002 has seen this message but not replied
 Message 30 by Godismyjudge, posted 01-28-2010 4:44 PM hooah212002 has seen this message but not replied

  
Larni
Member (Idle past 163 days)
Posts: 4000
From: Liverpool
Joined: 09-16-2005


(1)
Message 8 of 150 (542039)
01-07-2010 10:46 AM
Reply to: Message 6 by slevesque
01-07-2010 10:25 AM


Related species would have similar features, two species have similar features, therefore they are related
Which is fallacious.
By the same logic you could argue that a tiger is not related to a sand cat.
This only provides strong evidence that you will never be able to use evidence to alter the way you view the natural world.

This message is a reply to:
 Message 6 by slevesque, posted 01-07-2010 10:25 AM slevesque has replied

Replies to this message:
 Message 11 by slevesque, posted 01-07-2010 11:03 AM Larni has replied

  
Dr Adequate
Member (Idle past 284 days)
Posts: 16113
Joined: 07-20-2006


Message 9 of 150 (542040)
01-07-2010 10:47 AM
Reply to: Message 6 by slevesque
01-07-2010 10:25 AM


It's the classical case of affirming the consequent:
But you could say that of all scientific knowledge whatsoever.
Besides, any knowledgeable evolutionists should know this, considering the sizeable amount of convergent evolution examples in my biology book ...
But convergent evolution is superficial, it can't be expected to produce similar underlying morphology from lineages that started off different. No amount of convergent evolution will give the hummingbird moth the skeletoon of a hummingbird.
Besides which, I'm not sure that my lifestyle is sufficiently like that of a monkey to produce convergence ... still less the lifestyles of Archaeopteryx and T. rex. The notion that differences in lifestyle have produced divergence seems more plausible.
Edited by Dr Adequate, : No reason given.

This message is a reply to:
 Message 6 by slevesque, posted 01-07-2010 10:25 AM slevesque has replied

Replies to this message:
 Message 12 by slevesque, posted 01-07-2010 11:12 AM Dr Adequate has not replied

  
slevesque
Member (Idle past 4640 days)
Posts: 1456
Joined: 05-14-2009


Message 10 of 150 (542041)
01-07-2010 10:53 AM
Reply to: Message 7 by hooah212002
01-07-2010 10:41 AM


I would suggets you reread the OP, as CS has made it clear that he judges this line of reasoning to be sufficient to affirm relationship:
Creationists and IDists have asked for examples of one kind evolving into another and this is my attempt to share with them what I've found convincing of just that.
I'm trying to be very general here and am not implying that ostriches are direct decendents of velociraptors, but I think its obvious that birds did decend from theropods. And that its a great example of one kind becomming another.
(emphasis in original)
I found it convincing. Do you?
I'm not saying there are no other evidence as you have said.
What I'm saying is that CS has given only this evidence, and declared it to be sufficient to convince him of relationship.

This message is a reply to:
 Message 7 by hooah212002, posted 01-07-2010 10:41 AM hooah212002 has seen this message but not replied

Replies to this message:
 Message 15 by Peepul, posted 01-07-2010 12:39 PM slevesque has not replied

  
slevesque
Member (Idle past 4640 days)
Posts: 1456
Joined: 05-14-2009


Message 11 of 150 (542043)
01-07-2010 11:03 AM
Reply to: Message 8 by Larni
01-07-2010 10:46 AM


By the same logic you could argue that a tiger is not related to a sand cat.
I'm not sure if it is me misexpressing myself or maybe a lack of logical understanding on your part, but you cannot prove none-relationship by affirming the consequent.
Affirming the consequent is fallacious because it is not sufficient to prove the conclusion. It does not mean that the given conclusion is wrong, it just means that a correct logical path needs to be taken.
This only provides strong evidence that you will never be able to use evidence to alter the way you view the natural world.
Sorry for not being convinced by a fallacious argument ...
---------------
BTW, I know I use the word fallacious repeatedly, this is not an attack on CS. He is a very bright personand has shown it repeatedly, and logical ability is not in question. He just slipped in a hard-to-recognize fallacy and I'm trying to point it out. (Although with much more resistance then anticipated)
Edited by slevesque, : No reason given.
Edited by slevesque, : No reason given.

This message is a reply to:
 Message 8 by Larni, posted 01-07-2010 10:46 AM Larni has replied

Replies to this message:
 Message 17 by Larni, posted 01-07-2010 4:23 PM slevesque has replied

  
slevesque
Member (Idle past 4640 days)
Posts: 1456
Joined: 05-14-2009


Message 12 of 150 (542047)
01-07-2010 11:12 AM
Reply to: Message 9 by Dr Adequate
01-07-2010 10:47 AM


But you could say that of all scientific knowledge whatsoever.
If all of scientific knowledge is based on affirming the consequent, then we're in deep shizzles.
But convergent evolution is superficial, it can't be expected to produce similar underlying morphology from lineages that started off different. No amount of convergent evolution will give the hummingbird moth the skeletoon of a hummingbird.
Besides which, I'm not sure that my lifestyle is sufficiently like that of a monkey to produce convergence ... still less the lifestyles of Archaeopteryx and T. rex. The notion that differences in lifestyle have produced divergence seems more plausible.
Convergent evolution is simply an example as to why affirming similar morphology is unsufficient to confirm relationship. I could have done a similar analysis as CS with tasmanian tigers and dogs in terms of morphological similarity, and of course no one would have concluded relationship between the two as CS has with Emu and theropods.
I also want to specify that affirming the consequent is necessary for the conclusion to be possible. This can be seen with it's counterpart, denying the consequent:
Two related species will have similar features
two species do not have similar features
therefore they are not related.
Which is a valid argument. Therefore, it shows that similarity is a required characteristic to conclude relationship, but it is not a sufficient one.

This message is a reply to:
 Message 9 by Dr Adequate, posted 01-07-2010 10:47 AM Dr Adequate has not replied

Replies to this message:
 Message 20 by Blue Jay, posted 01-25-2010 12:56 PM slevesque has not replied

  
slevesque
Member (Idle past 4640 days)
Posts: 1456
Joined: 05-14-2009


Message 13 of 150 (542048)
01-07-2010 11:15 AM


Note also that CS (fallaciously) shows a relationship between Emu's and theropods, only to conclude a relationship with all Birds. (As per his title)
Which is also fallacious.

Replies to this message:
 Message 16 by New Cat's Eye, posted 01-07-2010 2:51 PM slevesque has not replied

  
Peepul
Member (Idle past 5017 days)
Posts: 206
Joined: 03-13-2009


Message 14 of 150 (542058)
01-07-2010 12:18 PM
Reply to: Message 3 by slevesque
01-07-2010 9:36 AM


quote:
Similarity, either in the phenotype or the genotype, does not prove relationship unfortunately.
.
Though it's one of the many strands of evidence that do, collectively, prove exactly that.
Some of the genotypic similarities are in themselves strong evidence of relationship - particularly elements that are non-functional such as ERVs, LINES, and pseudogenes.
Likewise similarities in genotype between creatures with strongly different phenotypes is very good evidence of relationship - when supported by fossils that show intermediates between them.
In the theropod / bird case, we don't have access to genetic data about theropods, but we do for birds, and they show the existence of pseudogenes, for example, for teeth. Here's info on some research on a mutant chicken with teeth.
Surprise: Chickens Can Grow Teeth | Live Science
We also have a wide variety of intermediates between the birds of today and their ancestors, most discovered quite recently. It's clear that feathers evolved first, in flightless dinosaurs, and were then co-opted for flight. There are intermediate feather types in the fossil record which have a simpler structure then feathers now.
Here's a nice link on feather evolution.
Feather evolution
This link makes clear that feathers are unlikely to have evolved from scales - so I think you're right about that (although this article is not primary literature).
Edited by Peepul, : mis-spelling of theropod

This message is a reply to:
 Message 3 by slevesque, posted 01-07-2010 9:36 AM slevesque has not replied

  
Peepul
Member (Idle past 5017 days)
Posts: 206
Joined: 03-13-2009


Message 15 of 150 (542060)
01-07-2010 12:39 PM
Reply to: Message 10 by slevesque
01-07-2010 10:53 AM


quote:
I'm not saying there are no other evidence as you have said.
What I'm saying is that CS has given only this evidence, and declared it to be sufficient to convince him of relationship.
I think that's fair comment Slevesque - but what do you think of the other evidence?

This message is a reply to:
 Message 10 by slevesque, posted 01-07-2010 10:53 AM slevesque has not replied

  
Newer Topic | Older Topic
Jump to:


Copyright 2001-2023 by EvC Forum, All Rights Reserved

™ Version 4.2
Innovative software from Qwixotic © 2024