|
Author
|
Topic: Prof. Davison's Challenge to NDE
|
peter borger
Member
Member # 722
|
posted 30. May 2006 11:41
quote:
If a single LUCA laid the foundations for the modern diversity in membranes, metabolism and so on, it must have had several different versions of many important genes, in addition to the universal sixty. Later lineages would each have pruned all but one from this set, giving rise to the current diversity in basic biochemical pathways.
SPEAKING ABOUT GENETIC REDUNDANCY!!!!
peebee
IP: Logged
|
|
Bruce Fast
Member
Member # 924
|
posted 30. May 2006 12:12
PB: "Biology is very clear about it – Darwin’s hypothesis of common descent is false."
I personally see a "common descent", albiet, not a Darwinian common descent. What I see is a common descent in nature that is very much akin to common descent in technology. One can realistically say that Microsoft Windows 3.1 is the common ancestor to Windows XP. You can also say that MsDos is the common ancestor to Windows 3.1. Would you agree that there is a sense in which "common descent" is a sensible description of the way life developed, albiet not random mutation by random mutation?
IP: Logged
|
|
Zachriel
Member
Member # 1793
|
posted 30. May 2006 15:07
peter borger: "The continuum Zachriel speaks of is the falsified Darwinian hypothesis of common descent."
That is incorrect. From my previous post, the continuum refers to the observed gradient of interfertility between extant organisms.
In Darwin's time, it was believed that species had been created inviolate. Darwin being a meticulous researcher gathered data from a variety of sources to show that species grade continuously into varieties. And, in fact, they do. Occasional interbreeding between closely related species is predicted by the Theory of Evolution.
peter borger: "This observation made Darwin believe all organism were descended from one single primordial unicellular organism."
Darwin was usually very careful in his assertions. He could not show that all organisms shared a common ancestry, so he posited 'one or a few'.
IP: Logged
|
|
Zachriel
Member
Member # 1793
|
posted 30. May 2006 15:08
Melvin H. Fox: "My background is mathematics and I must confess my uneasiness with respect to the slippery definition of species you have offered."
Not slippery but chaotic. I assume as a mathematician, you are familiar with fractal borders, e.g. the Mandelbrot Set. Some things are definitely inside the Set. Some things are definitely outside the Set. Some things must be judged by looking very carefully at the border. And some things are just too close to know for sure (beyond the available resolution).
Speciation is a real biological concept, but there are several common and related definitions of species. When populations exhibit low gene flow sufficient to maintain significant morphological or behavioral differences, then they are usually classified as separate species. On the other hand, scientists will often state and use more specific definitions suitable for their own research. Just like mathematicians.
Melvin H. Fox: "Let’s say we have two populations separated in such a way as the gene flow between them is low to the extreme. Further suppose that this separation extends over countless generations. Will these two populations eventually become reproductively incompatible?"
Stochastic processes will continue to lead to the divergence of the isolated populations, but as with all such processes, they may meander closer and farther, perhaps even reuniting. However, if they no longer exchange genes, eventually they will become genetically incompatible. There are a variety of specific biological mechanisms by which this might occur.
And there is no evidence of a supposed barrier to continued divergence.
Melvin H. Fox: "In other words, is the limit of this process total incompatibility? If so, has this occurred?"
Common Descent is inferred from the nested hierarchy. There are astounding correlations between extant organisms, e.g. having mammaries and the number of ear bones. There are ad hoc modifications of existing structure. And the succession of fossils. These correlations are called the nested hierarchy and are exactly the sort of pattern expected from common descent. Genomics is considered conclusive by nearly all researchers in the field.
As a mathematician, you might want to read about how other mathematicians have shown that the nested hierarchy is independent of human cognition, but can be constructed analytically. In fact, most phylogenetic trees are done by computer nowadays.
Melvin H. Fox: "If it has, when and where did it occur?"
When did Mandelbrot cross the borders of his Set? When did Zeno reach his destination? We can't always say for sure when populations first become completely, absolutely, finally, genetically isolated. Even if we show that a parent species can't interbreed with its child, it may be that we discover later that genes flow through a related intermediary. However, most organisms are genetically isolated, and those that aren't are usually closely related in other respects.
When one animal turns and enters a new part of the forest, that may be the moment a new species begins, but there is no way to tell until afterwards.
Biology is biology. And history is what it is, with all its contingency and necessity, its twists and turns.
[ 30. May 2006, 15:53: Message edited by: Zachriel ]
IP: Logged
|
|
Zachriel
Member
Member # 1793
|
posted 30. May 2006 15:19
Bruce Fast: "I read about the cambrian explosion. Prior to the explosion there seems to be virtually no evidence of any multi-cellular animal life."
Then let's just agree that all chordates are related by common descent.
This shows the weakness of the argument. As the frontiers of knowledge are pushed further and further, the argument from ignorance is forced to retreat further and further back in time, such as before the fossilization of hard body parts or to the evolution of the flagellum. However, there is now substantial evidence of precursors to many of the organisms in the Cambrian Explosion.
Bruce Fast: "No one seems to suggest that any biologist who was transported back to 10 mil after the beginning of the cambrian would say, 'hey, there's about 50 species here'. No, it appears that the biologist transported back in time would recognize the variety as 'phila'."
Well, a mammalian would certainly consider them phyla, but that's just mammal-chauvinism for you. But to someone of the time period, they would look just like species. Who could have foretold that those little 'worms' would amount to much?
Bruce Fast: "One can realistically say that Microsoft Windows 3.1 is the common ancestor to Windows XP."
Sorry, but Windows clearly adapted features from Apple Computers and violates the nested hierarchy as design usually does. Biological descent does not show this type of borrowing, but forms a distinct nested hierarchy.
IP: Logged
|
|
Shi
Member
Member # 1923
|
posted 30. May 2006 15:57
quote:
Sorry, but Windows clearly adapted features from Apple Computers and violates the nested hierarchy as design usually does. Biological descent does not show this type of borrowing, but forms a distinct nested hierarchy.
Based on DNA similarity, human evolved from chimpanzees. But a portion of human DNA is more closely related to gorilla. At trait level, some human traits are similar to chimpanzee but some are more related to other primates. The data is not consistent with the idea that human is derived solely from chimpanzee.
IP: Logged
|
|
Zachriel
Member
Member # 1793
|
posted 30. May 2006 16:23
Shi: "The data is not consistent with the idea that human is derived solely from chimpanzee."
Humans are not "derived" from chimpanzees, but are posited to share a common ancestor. However, if you have a cite, I would be happy to look at it.
By the way, the people who actually sequenced the chimpanzee genome hold a different opinion. But hey! Whadda they know!?
The Chimpanzee Sequencing and Analysis Consortium: More than a century ago Darwin and Huxley posited that humans share recent common ancestors with the African great apes. Modern molecular studies have spectacularly confirmed this prediction and have refined the relationships, showing that the common chimpanzee (Pan troglodytes) and bonobo (Pan paniscus or pygmy chimpanzee) are our closest living evolutionary relatives.
[ 30. May 2006, 16:27: Message edited by: Zachriel ]
IP: Logged
|
|
John A. Davison
Member
Member # 1425
|
posted 30. May 2006 16:37
The oldest reference to Homo sapiens is under 100,000 years and even that is questionable. I will stick to my guns thank you very much. Penguins and cichlids are not mammals either. If nmy challenge must be met, at least have it be read and comprehended first.
IP: Logged
|
|
Shi
Member
Member # 1923
|
posted 30. May 2006 16:38
Zach, You can start with the recent Nature article Genetic evidence for complex speciation of humans and chimpanzees by Patterson, N., et al. This article cited the following old paper which also states the same thing that some human DNA is more related to gorilla. The data is more consistent with a designer who took some information from gorilla as well as from the common ancestor of human and chimp in creating humans.
Mol Biol Evol. 1997 Mar;14(3):248-65.
Molecular phylogeny of the hominoids: inferences from multiple independent DNA sequence data sets.
Ruvolo M.
Department of Anthropology, Harvard University, Cambridge, Massachusetts 02138, USA. ruvolo@fas.harvard.edu
Abstract (shortened)
Consensus on the evolutionary relationships of humans, chimpanzees, and gorillas has not been reached, despite the existence of a number of DNA sequence data sets relating to the phylogeny, partly because not all gene trees from these data sets agree. All available DNA sequence data sets showing phylogenetic resolution among the hominoids are grouped according to genetic linkage of their corresponding genes to form independent data sets. Of the 14 independent data sets defined in this way, 11 support a human-chimpanzee clade, 2 support a chimpanzee-gorilla clade, and one supports a human-gorilla clade.
IP: Logged
|
|
Shi
Member
Member # 1923
|
posted 30. May 2006 17:02
Phenotypes are decided by both gene functions and gene organizations (how genes are ordered to each other). There is a trend in evolution that early life forms are created by using distinct genes while later ones are created more by using distinct organizations/combinations of homologous genes. This is clearly the case in the creation of humans. Human is distince in chromosome organization from all other primates, having 23 pair rather than 24 pair. The closest relatives to chimpanzee are humans based on DNA sequence but are other primates based on chromosome organiation (and also life style). So difference in gene organization correlates better with difference in traits. And ordered change in gene organization can be better explained by a designer than by random events.
IP: Logged
|
|
Zachriel
Member
Member # 1793
|
posted 30. May 2006 17:03
Shi: "The data is more consistent with a designer who took some information from gorilla as well as from the common ancestor of human and chimp in creating humans."
You quoted from a paper from 1997. Let's look more closely at what the authors determined from the fragmentary evidence they had available.
"The multiple-locus test (Wu 1991), which evaluates hypotheses using gene tree-species tree mismatch probabilities in a likelihood ratio test, favors the phylogeny with a Homo-Pan clade and rejects the other alternatives with a P value of 0.002. When the probabilities are modified to reflect effective population size differences among different types of genetic loci, the observed data set distribution is even more likely under the Homo-Pan clade hypothesis."
And
"The implication of the multiple-locus test is that existing DNA sequence data sets provide overwhelming and sufficient support for a human-chimpanzee clade"
But there has been a great deal of evidence in genomics accumulated since then. Certainly the people who actually sequenced the chimpanzee genome must be considered valid authorities.
IP: Logged
|
|
Zachriel
Member
Member # 1793
|
posted 30. May 2006 17:16
Shi: "And ordered change in gene organization can be better explained by a designer than by random events."
Gene recombination can be observed to be a stochastic process, and includes gene duplication, insertions, translocations, inversions, frame shift, etc. And these recombinations can be shown to occasionally produce a beneficial effect.
IP: Logged
|
|
Shi
Member
Member # 1923
|
posted 30. May 2006 17:38
No one doubts that 90-95% of human DNA is more closely related to chimps than to gorillas. Based on this, I accept that it is more likely for human and chimp to share a common ancestor than for human and gorilla to share one. Given that to be true, what could be the explanation for the fact that 1-5% of human DNA is more closely related to gorilla than to chimps? Darwinists simply ignored it instead of trying to give an explaination.
IP: Logged
|
|
John A. Davison
Member
Member # 1425
|
posted 30. May 2006 18:13
In my opinion all primates share a common information source. The diferences consist largely and perhaps entirely on the basis of which portions of this common pool are silenced and which are expressed. There is no need to introduce any new information to account for all of primate evolution. How much further this can be extended remains to be determined. Allelic mutation has played no role in this process or in any other aspect of evolution for that matter.
IP: Logged
|
|
Bruce Fast
Member
Member # 924
|
posted 30. May 2006 18:24
Zachriel: quote:
Sorry, but Windows clearly adapted features from Apple Computers
It seems that both Apple and Windows absconded the desktop metaphore, icons, the mouse and the ethernet, ie all that is "windows" from Xerox PARC.
Zachriel: quote:
Sorry, but Windows ... violates the nested hierarchy as design usually does. Biological descent does not show this type of borrowing, but forms a distinct nested hierarchy.
What I have seen of convergence, even molecular convergence, seems awfully like biology does do this type of borrowing. You would agree that convergence is vastly more widespread than was expected, would you not?
HGT, a rampent phenomenon in the lower orders of life, also seems to exist in the higher orders to some extent, and clearly violates the nested hierarchy.
Simon Conway Morris, and other "neo-Darwinists" have concluded, based upon the rampant reality of convergence, that Gould's view of contingency is in error.
Zachriel: quote:
Well, a mammalian would certainly consider them phyla, but that's just mammal-chauvinism for you. But to someone of the time period, they would look just like species. Who could have foretold that those little 'worms' would amount to much?
What a wierd analysis. A bunch of the phila that appeared in the cambrian explosion never did amount to much. It is clearly not "amounting to much" that determines whether an organism is in its own philum.
Gentlemen, do you agree with me that a biologist who went back in time to just after the cambrian explosion would recognize the organisms as being "of separate phila", and likewise after the appearance of the classes and orders, or do you agree with Zachriel that an observation just after the arrival of these novel creatures would have concluded that they be taxonomically seen as being only of different species, or genus?
IP: Logged
|
|
|
Printer-friendly view of this topic