usfan
Well-Known Member
I find it very curious, that the indignant debaters and True Believers for common descent don't even seem to know the main arguments for their own theory.. 
How about this one?
Vestigiality
Vestigial organs: These are organs or conditions that do not seem to have a current function, and are explained as a 'leftover' from a previous incarnation.
There are a lot of assumptions, calling something 'vestigial!' It is based mostly on a 'looks like!' fallacy of plausibility, not anything evidentiary or experimental.
It was a popular 'proof!' in the 19th century, when they didn't know what some organs were for...
"The 'vestigial organ' argument uses as a premise the assertion that the organ in question has no function. There is no way however, in which this negative assertion can be arrived at scientifically. That is, one can not prove that something does not exist (in this case a certain function), since of course if it does not exist one cannot observe it, and therefore one can say nothing about it scientifically. The best we can do is to state that despite diligent effort, no function was discovered for a given organ. However it may be that some future investigator will the discover the function. Consequently, the vestigial organ argument has as a premise, either a statement of ignorance (I couldn't identify the function), or a scientifically invalid claim (it does not have a function). Such an argument, from ignorance, or from negative results, is not valid scientifically, and has no place in observational or experimental science.
"Since it is not possible to unambiguously identify useless structures, and since the structure of the argument used is not scientifically valid, I conclude that ‘vestigial organs’ provide no special evidence for the theory of evolution." ~zoologist S. R. Scadding (University of Guelph, 175f.)
Here is a brief clip from wiki about vestigiality:
In 1893, Robert Wiedersheim published The Structure of Man, a book on human anatomy and its relevance to man's evolutionary history. This book contained a list of 86 human organs that he considered vestigial, or as Wiedersheim himself explained: "Organs having become wholly or in part functionless, some appearing in the Embryo alone, others present during Life constantly or inconstantly. For the greater part Organs which may be rightly termed Vestigial."[3] His list of supposedly vestigial organs included many of the examples on this page as well as others then mistakenly believed to be purely vestigial, such as the pineal gland, the thymus gland, and the pituitary gland. Some of these organs that had lost their obvious, original functions later turned out to have retained functions that had gone unrecognized before the discovery of hormones or many of the functions and tissues of the immune system'
To assume vestigiality based on assumptions of descent, and a plausible 'looks like!' speculation makes interesting science fiction, but it is poor science.. just opinions or beliefs asserted without evidence.
The term 'vestigial' itself is circular reasoning, using an assumption of common descent to prove common descent. Something vestigial, by definition, is a useless appendage that is left over from a previous evolutionary incarnation. But it is more accurate to say that if a function is unknown, why must you assume vestigiality? Scadding's argument above addresses this directly.
These are projections.. opinions about some organ that the observer does not know the function of, or has a 'looks like!' plausibility of fitting the definition of 'vestigial'. This is not evidence. It is belief.
How about this one?
Vestigiality
Vestigial organs: These are organs or conditions that do not seem to have a current function, and are explained as a 'leftover' from a previous incarnation.
There are a lot of assumptions, calling something 'vestigial!' It is based mostly on a 'looks like!' fallacy of plausibility, not anything evidentiary or experimental.
It was a popular 'proof!' in the 19th century, when they didn't know what some organs were for...
"The 'vestigial organ' argument uses as a premise the assertion that the organ in question has no function. There is no way however, in which this negative assertion can be arrived at scientifically. That is, one can not prove that something does not exist (in this case a certain function), since of course if it does not exist one cannot observe it, and therefore one can say nothing about it scientifically. The best we can do is to state that despite diligent effort, no function was discovered for a given organ. However it may be that some future investigator will the discover the function. Consequently, the vestigial organ argument has as a premise, either a statement of ignorance (I couldn't identify the function), or a scientifically invalid claim (it does not have a function). Such an argument, from ignorance, or from negative results, is not valid scientifically, and has no place in observational or experimental science.
"Since it is not possible to unambiguously identify useless structures, and since the structure of the argument used is not scientifically valid, I conclude that ‘vestigial organs’ provide no special evidence for the theory of evolution." ~zoologist S. R. Scadding (University of Guelph, 175f.)
Here is a brief clip from wiki about vestigiality:
In 1893, Robert Wiedersheim published The Structure of Man, a book on human anatomy and its relevance to man's evolutionary history. This book contained a list of 86 human organs that he considered vestigial, or as Wiedersheim himself explained: "Organs having become wholly or in part functionless, some appearing in the Embryo alone, others present during Life constantly or inconstantly. For the greater part Organs which may be rightly termed Vestigial."[3] His list of supposedly vestigial organs included many of the examples on this page as well as others then mistakenly believed to be purely vestigial, such as the pineal gland, the thymus gland, and the pituitary gland. Some of these organs that had lost their obvious, original functions later turned out to have retained functions that had gone unrecognized before the discovery of hormones or many of the functions and tissues of the immune system'
To assume vestigiality based on assumptions of descent, and a plausible 'looks like!' speculation makes interesting science fiction, but it is poor science.. just opinions or beliefs asserted without evidence.
The term 'vestigial' itself is circular reasoning, using an assumption of common descent to prove common descent. Something vestigial, by definition, is a useless appendage that is left over from a previous evolutionary incarnation. But it is more accurate to say that if a function is unknown, why must you assume vestigiality? Scadding's argument above addresses this directly.
These are projections.. opinions about some organ that the observer does not know the function of, or has a 'looks like!' plausibility of fitting the definition of 'vestigial'. This is not evidence. It is belief.
