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Author Topic:   Extinction of Dinosaurs: Consensus Reached . . . mostly
kbertsche
Member (Idle past 204 days)
Posts: 1427
From: San Jose, CA, USA
Joined: 05-10-2007


Message 16 of 53 (549887)
03-11-2010 10:36 AM
Reply to: Message 15 by Matt P
03-10-2010 12:10 PM


Re: Lack of other impact-induced evidence
Yes, the evidence for impacts at other extinctions is not so strong as the K-T and is disputed. But the claim that "there is no evidence of impacts" or that there is "no empirical evidence" is blatantly false. (And remember that the evidence for an impact at the K-T was hotly disputed for nearly a decade before general acceptance.)
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Blue Jay
Member (Idle past 770 days)
Posts: 2843
From: You couldn't pronounce it with your mouthparts
Joined: 02-04-2008


Message 17 of 53 (549893)
03-11-2010 11:00 AM
Reply to: Message 6 by Dr Jack
03-06-2010 12:03 PM


Hi, Mr Jack.

Mr Jack writes:

Maybe, but it certainly should be able to explain what it's trying to explain - in this case why the dinosaurs died out. The impact isn't an answer to that question because it doesn't explain why other groups didn't die out and thus leaves the question unanswered.

I disagreed with it the first time you said it, and I still disagree with it now.
Why does the survival of some groups of mammals and birds invalidate the impact as a reason for the extinction of the dinosaurs?

-----

Mr Jack writes:

It is simply not possible to find clear dividing lines like that between groups which survived and groups which didn't.

Nothing in biology ever has clear dividing lines. Like everything else Iíve ever seen, there are only messy trends with a lot of noise. Why is this such a problem for you in this one instance?


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

Darwin loves you.


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Blue Jay
Member (Idle past 770 days)
Posts: 2843
From: You couldn't pronounce it with your mouthparts
Joined: 02-04-2008


Message 18 of 53 (549896)
03-11-2010 11:05 AM
Reply to: Message 12 by Larni
03-09-2010 1:07 PM


Hi, Larni.

Larni writes:

Birds could....I dunno, I don't suppose they could do much but they must have done something right.

Birds could fly.

As resources become sparse, the ability to travel greater distances in a shorter period of time with less effort than running gives them the advantage.


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

Darwin loves you.


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Taq
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Posts: 7672
Joined: 03-06-2009
Member Rating: 3.2


Message 19 of 53 (549897)
03-11-2010 11:13 AM
Reply to: Message 18 by Blue Jay
03-11-2010 11:05 AM


Birds could fly.

As resources become sparse, the ability to travel greater distances in a shorter period of time with less effort than running gives them the advantage.

That's what I was thinking too. Also, feathers provide nice insulation against a "nuclear winter" caused by such a large impact. Mammals were also nicely insulated and given their burrowing lifestyle may have had access to food unavailable to species living above ground. Crocodillians, being cold blooded, could shut down their metabolism in cold times and would require much less food. Could the extinction of the dinosaurs also suggest that a vast majority of dinosaurs species were warm blooded?

For me, the most interesting feature of the extinction event is the way in which it favored smaller species. If memory serves, something like 90% of species who were 50 kg or larger went extinct while those 50 kg and smaller survived much better. To me, this indicates a very dramatic reduction in available food sources.


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Dr Jack
Member (Idle past 178 days)
Posts: 3507
From: Leicester, England
Joined: 07-14-2003


Message 20 of 53 (549907)
03-11-2010 12:02 PM
Reply to: Message 17 by Blue Jay
03-11-2010 11:00 AM


I disagreed with it the first time you said it, and I still disagree with it now. Why does the survival of some groups of mammals and birds invalidate the impact as a reason for the extinction of the dinosaurs?

It invalidates it as an explaination, because it's not explained it. Suppose you ask me how I got to be a Games Programmer and I reply "I went to school" - it'd be true, to a point, without all that schooling I wouldn't have the skills I need but it doesn't really answer the question but it doesn't address why I'm a Games Programmer and everyone else who went to school isn't.

The impact is not an explaination because it doesn't explain the survival patterns.

Nothing in biology ever has clear dividing lines. Like everything else Iíve ever seen, there are only messy trends with a lot of noise. Why is this such a problem for you in this one instance?

True, but then we're just left asking why did no non-avian dinosaurs make it through in that noise?


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Taq
Member
Posts: 7672
Joined: 03-06-2009
Member Rating: 3.2


Message 21 of 53 (549915)
03-11-2010 12:43 PM
Reply to: Message 20 by Dr Jack
03-11-2010 12:02 PM


It invalidates it as an explaination, because it's not explained it. Suppose you ask me how I got to be a Games Programmer and I reply "I went to school" - it'd be true, to a point, without all that schooling I wouldn't have the skills I need but it doesn't really answer the question but it doesn't address why I'm a Games Programmer and everyone else who went to school isn't.

The impact is not an explaination because it doesn't explain the survival patterns.

I think everyone agrees that the impact is just part of the explanation. The impact is being cited as the "trigger" for the K-Pg event. So perhaps a better analogy would be how "pulling the trigger" is an integral part of the explanation of how a bullet is ejected out the end of a gun barrel but not the complete explanation.


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Blue Jay
Member (Idle past 770 days)
Posts: 2843
From: You couldn't pronounce it with your mouthparts
Joined: 02-04-2008


Message 22 of 53 (549988)
03-11-2010 9:08 PM
Reply to: Message 20 by Dr Jack
03-11-2010 12:02 PM


Hi, Mr Jack.

Mr Jack writes:

The impact is not an explaination because it doesn't explain the survival patterns.

A major disaster hit my home town about 10 years ago. Every house on one street was completely leveled, except for the house where some of our friends from church lived.

The "tornado theory" clearly explains what happened to all those houses, even though it can't explain why my friends' house was not destroyed. So, does the survival of my friends' house pose a serious problem for the "tornado theory"?

The "tornado theory" is a theory about the mechanism of destruction, not about the mechanism of survival. How can a tornado possibly explain why my friends' house survived? And, why would it have to?


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

Darwin loves you.


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pandion
Member (Idle past 1073 days)
Posts: 166
From: Houston
Joined: 04-06-2009


Message 23 of 53 (550020)
03-12-2010 1:19 AM
Reply to: Message 22 by Blue Jay
03-11-2010 9:08 PM


So you are saying that your friend's house didn't have any damage whatsoever? There were no shingles blown off? There were no windows blown out? The siding wasn't damaged?

What is the "tornado theory?" What does it have to do with your church? Why does it have to explain a survival pattern?

Is it possible that I have actually grasped your point? Naaah!

Edited by pandion, : No reason given.


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Dr Jack
Member (Idle past 178 days)
Posts: 3507
From: Leicester, England
Joined: 07-14-2003


Message 24 of 53 (550024)
03-12-2010 4:35 AM
Reply to: Message 22 by Blue Jay
03-11-2010 9:08 PM


Good analogy, let me think on that.

I'd say whether tornado theory provides an answer would depend on the question - it seems to me the question of the K-T extinction event is why did the dinosaurs die out when all these other things didn't. A question which is equivalent to asking why your friends house survived when the others didn't. A question which cannot be answered simply by saying there was a tornado.


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Blue Jay
Member (Idle past 770 days)
Posts: 2843
From: You couldn't pronounce it with your mouthparts
Joined: 02-04-2008


Message 25 of 53 (550043)
03-12-2010 9:29 AM
Reply to: Message 23 by pandion
03-12-2010 1:19 AM


Hi, Pandion.

pandion writes:

Is it possible that I have actually grasped your point? Naaah!

I'm... not sure.

If you're being sarcastic, use a smiley to help me out.

-----

Just in case, I do want to address one point:

pandion writes:

So you are saying that your friend's house didn't have any damage whatsoever? There were no shingles blown off? There were no windows blown out? The siding wasn't damaged?

One eave was broken off, and there were a good number of holes on one side of the building, from flying debris.

Just like the mammals and birds still suffered damage, so to speak: enantiornithiform and hesperornithiform birds, for instance, went completely extinct at the K-T, along with the Laurasian marsupials.

It is interesting to note that none of the major mammalian clades went completely extinct at the K-T, though.


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

Darwin loves you.


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Dr Jack
Member (Idle past 178 days)
Posts: 3507
From: Leicester, England
Joined: 07-14-2003


Message 26 of 53 (550046)
03-12-2010 10:18 AM
Reply to: Message 25 by Blue Jay
03-12-2010 9:29 AM


It is interesting to note that none of the major mammalian clades went completely extinct at the K-T, though.

Hmm... aren't the "major" mamalian clades defined by their existence post K-T, so - by definition - survived? As I understand it the fossil record of most mammalian clades are pretty scarce pre K-T anyway, and we only know they diverged prior to it because of genetic studies using molecular clocks.


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Blue Jay
Member (Idle past 770 days)
Posts: 2843
From: You couldn't pronounce it with your mouthparts
Joined: 02-04-2008


Message 27 of 53 (550050)
03-12-2010 10:34 AM
Reply to: Message 26 by Dr Jack
03-12-2010 10:18 AM


Hi, Mr Jack.

Mr Jack writes:

Hmm... aren't the "major" mamalian clades defined by their existence post K-T, so - by definition - survived?

I don't know. I've only ever heard of four "major" mammalian clades---monotremes, multituberculates, marsupials and placentals---and I'm relatively certain that all of them are found before and after the K-T.


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

Darwin loves you.


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Replies to this message:
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Dr Jack
Member (Idle past 178 days)
Posts: 3507
From: Leicester, England
Joined: 07-14-2003


Message 28 of 53 (550054)
03-12-2010 10:56 AM
Reply to: Message 27 by Blue Jay
03-12-2010 10:34 AM


don't know. I've only ever heard of four "major" mammalian clades---monotremes, multituberculates, marsupials and placentals---and I'm relatively certain that all of them are found before and after the K-T.

Ah, those major mammalian clades.

Yes, quite right. I was thinking more around the 'Order' level.


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Larni
Member
Posts: 3975
From: Liverpool
Joined: 09-16-2005
Member Rating: 8.1


Message 29 of 53 (550178)
03-13-2010 11:42 AM
Reply to: Message 18 by Blue Jay
03-11-2010 11:05 AM


Birds could fly.

Good grief....

I must remember to think! I must remember to think!


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barbara
Member (Idle past 2875 days)
Posts: 167
Joined: 07-19-2010


Message 30 of 53 (581867)
09-17-2010 8:51 PM
Reply to: Message 15 by Matt P
03-10-2010 12:10 PM


Re: Lack of other impact-induced evidence
Since there is no clear evidence of a cause for a massive "extinction" event perhaps the real reason is the dinosaurs did not go extinct but descent with modification is what caused their appearance to change over time. This fits under evolutionists explanation perfectly.

If fact, nothing has ever been extinct, just changed in appearance over time. If the entire group of all reptiles all die then extinction is a better choice to describe it makes sense.


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