Originally posted by Andrew Hamiltonok, its perhaps so simple that its too obvious, birds according to the hypothesis, are supposed to have evolved from reptiles, now reptiles are cold bloodied, birds are not, now how does the hypothesis account for this difference. its really a very simple question, no, i am implying that what may be a fact today, may not be tomorrow.
[b]…how you are able to account for or explain …. the 'fact', i use the term lightly here in the science forum, that birds are warm bloodied and reptiles are cold bloodied.
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I don’t understand what you are getting at; what is there to “explain” or “account for” about the fact that “birds are warm bloodied and reptiles are cold bloodied”? ...[text shortened]... re you implying it isn’t a “fact” that birds are warm bloodied and reptiles are cold bloodied?[/b]
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Originally posted by PBE6ok so now that the goal posts have been shifted, i need to rephrase my question, how does the hypothesis account for the fact that birds are at one end of the body temperature continuum spectrum and reptiles are at the other end? is that better? seeing that they had a common ancestor?
I believe he's asking how it's possible that both warm-blooded and cold-blooded animals evolved from the same ancestor. I believe the answer is that the terms "warm-blooded" and "cold-blooded" used as absolutes are outdated, and in fact there is an observed continuum between these two extremes:
http://en.wikipedia.org/wiki/Warm_blooded
http://en.wikipedia. ...[text shortened]... t exchanger properties of the rete mirabile:
http://en.wikipedia.org/wiki/Rete_mirabile
Originally posted by PBE6…I believe the answer is that the terms "warm-blooded" and "cold-blooded" used as absolutes are outdated
I believe he's asking how it's possible that both warm-blooded and cold-blooded animals evolved from the same ancestor. I believe the answer is that the terms "warm-blooded" and "cold-blooded" used as absolutes are outdated, and in fact there is an observed continuum between these two extremes:
http://en.wikipedia.org/wiki/Warm_blooded
http://en.wikipedia. ...[text shortened]... t exchanger properties of the rete mirabile:
http://en.wikipedia.org/wiki/Rete_mirabile
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robbie carrobie
Is that it? -I mean, is the problem here is that you believe that "warm-blooded" and "cold-blooded" are absolutes with no possible continuum between these two extremes?
-if so, I only have to point out the platypus as a living example of an animal that is somewhere between these two extremes (it generates some of its own heat but it doesn’t do much to keep its body temperature constant and its temperature fluctuates wildly like that of a cold-bloodied animal) and there are several other similar living examples.
Originally posted by robbie carrobieNot trying to be difficult here, but which hypothesis are you referring to?
ok so now that the goal posts have been shifted, i need to rephrase my question, how does the hypothesis account for the fact that birds are at one end of the body temperature continuum spectrum and reptiles are at the other end? is that better? seeing that they had a common ancestor?
(a) The hypothesis that birds evolved from reptiles?
(b) The hypothesis that birds and reptiles evolved from a common ancestor?
(c) The hypothesis that evolution accounts for speciation?
(d) Another hypothesis?
Originally posted by Andrew Hamiltonis that the answer, a duck billed platypus, mmm, is not very convincing, nor reptilian, nor bird like, although it does lay eggs! and its considered mammalian, if i am not mistaken.
[b]…I believe the answer is that the terms "warm-blooded" and "cold-blooded" used as absolutes are outdated
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robbie carrobie
Is that it? -I mean, is the problem here is that you believe that "warm-blooded" and "cold-blooded" are absolutes with no possible continuum between these two extremes?
-if so, I only have to point out the platyp ...[text shortened]... ike that of a cold-bloodied animal) and there are several other similar living examples.[/b]
Originally posted by PBE6take your pick!
Not trying to be difficult here, but which hypothesis are you referring to?
(a) The hypothesis that birds evolved from reptiles?
(b) The hypothesis that birds and reptiles evolved from a common ancestor?
(c) The hypothesis that evolution accounts for speciation?
(d) Another hypothesis?
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Originally posted by robbie carrobie…is not very convincing
is that the answer, a duck billed platypus, mmm, is not very convincing, nor reptilian, nor bird like, although it does lay eggs! and its considered mammalian, if i am not mistaken.
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What is “not very convincing”?
would you deny that it has a metabolism somewhere between that of a typical warm bloodied animal and a typical cold bloodied one?
It is formally categorised as “warm bloodied” because it produces some significant amounts of heat but, never the less, has a metabolism somewhere between the two extremes.
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Originally posted by Andrew Hamiltonno i am not denying that it lies somewhere in between, the article that was posted also mentioned other species that are somewhere in between like bats for example, but what are you saying here Andrew, that a species can 'move along', the spectrum, from one extreme to the other? if so then thats fine, i was not challenging the idea, i really did want to know what you guys thought about it, how it was theorised to have occurred.
[b]…is not very convincing
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What is “not very convincing”?
would you deny that it has a metabolism somewhere between that of a typical warm bloodied animal and a typical cold bloodied one?[/b]
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Originally posted by robbie carrobie…how does the hypothesis ACCOUNT for the fact that birds are at one end of the body temperature CONTINUUM spectrum and reptiles are at the other end?
ok so now that the goal posts have been shifted, i need to rephrase my question, how does the hypothesis account for the fact that birds are at one end of the body temperature continuum spectrum and reptiles are at the other end? is that better? seeing that they had a common ancestor?
..…(my emphasis)
Hang on -Just noticed you used the words “CONTINUUM spectrum” there; -does that mean you DO acknowledge the fact that there IS a CONTINUOUS spectrum between worm bloodied and cold blooded? If so, if the “hypothesis” you are referring to is simply evolution, then how can there be anything to “ACCOUNT for”? -I mean, the CONTINUOUS spectrum between the two extremes would allow many missing links from one extreme to the other allowing evolution to make the transition from one to the other in very small and thus creditable steps -so what’s to “ACCOUNT for”?
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Originally posted by Andrew Hamiltonyes i genuinely want to know how it is theorised that this occured, i was not messing as i usually do, sorry i should have made that clear! so what you are essentially saying is there may have been a whole series of at present "missing links", which stem from reptiles to birds and in the process of evolution, these small increments were passed on from one species to the next. ok, that's quite simple, that's all i was asking, you can relax now 🙂
[b]…how does the hypothesis ACCOUNT for the fact that birds are at one end of the body temperature CONTINUUM spectrum and reptiles are at the other end?
..…(my emphasis)
Hang on -Just noticed you used the words “CONTINUUM spectrum” there; -does that mean you DO enlarge the fat that there IS a CONTINUOUS spectrum between worm bloodied and col ...[text shortened]... ition from one to the other in very small and thus creditable steps -so what’s to “ACCOUNT for”?[/b]
Originally posted by robbie carrobieHave you been drinking this evening?? If not,........i think you should.
yes i genuinely want to know how it is theorised that this occured, i was not messing as i usually do, sorry i should have made that clear! so what you are essentially saying is there may have been a whole series of at present "missing links", which stem from reptiles to birds and in the process of evolution, these small increments were passed on fro ...[text shortened]... species to the next. ok, that's quite simple, that's all i was asking, you can relax now 🙂