Re: Request


"Zoe" <muze10@xxxxxxx> wrote in message
news:egq2f1hlt2ek3bjd2es5jrmo4i3euksnl9@xxxxxxxxxx
> On Sun, 31 Jul 2005 17:53:55 -0500, "Steven J."
> <sjt1957NOSPAM@xxxxxxxxxxxxxxxxxxxx> wrote:
>
>>
>>"Zoe" <muze10@xxxxxxx> wrote in message
>>news:igsne1tsdue4nfr1b8rgd1he8hq6cjtq3i@xxxxxxxxxx
>>> On Wed, 27 Jul 2005 23:54:26 -0500, "Steven J."
>>> <sjt1957NOSPAM@xxxxxxxxxxxxxxxxxxxx> wrote:
>>>
>>-- [snip]
>>>
>>>>For that matter, again, if random events had no order governing them,
>>>>then
>>>>probability as a field of mathematics could not exist. Your position as
>>>>stated above is pure obstinant folly.
>>>
>>> probability and statistics does not explain how a cardboard box is put
>>> together. Neither does it explain how a certain number of chromosomes
>>> are consistently found in any particular life form. It merely
>>> predicts the chances of a single, discrete action occurring. These
>>> threads have had to do with how systems are put together.
>>>
>>Zoe, I thought that we had established that, in fact, a "certain number of
>>chromosomes" is not found consistently in any particular species; there
>>are
>>species with varying numbers of chromosomes in different individuals.
>>Heredity explains (to the extent that heredity is understood) why, in
>>general, chromosome counts don't vary wildly from parent to offspring or
>>individual to individual within a species.
>
> Steven, I'm talking about the usefulness of probability and statistics
> in explaining how a cardboard box is put together or in determining
> how chromosomes are consistently the same for any group of life forms.
> It isn't useful for these purposes, is it?
>
Well, no. But before you were talking about the usefulness of probability
in constructing cardboard boxes, you were talking about random mutations as
though the laws of probability did not apply to them.
>
>>> So now, are you saying that random events are credited with pulling
>>> together a digestive system or a circulatory system or a cardboard
>>> box? Or are you taking a fully-formed reproductive system and
>>> applying your evolutionary theory of mutations to it? I am really
>>> interested in the construction of the system, not in the mutations
>>> that can happen to the construction.
>>>
>>No, I am not saying that random events are credited with putting together
>>a
>>digestive system (at least, not by themselves); random events in
>>combination
>>with natural selection (reproduction, variation, and differential
>>reproductive success) put complex structures together.
>
> and this is the process that has not yet been explained by posters to
> TO -- not one. Please describe a scenario, based on facts, not
> fantasy, of how a digestive system comes together through random
> events in combination with natural selection. And you cannot use
> reproduction, variation, and differential reproductive success unless
> you are willing to concede that the machinery was already in place,
> fully functioning, after which comes along your mutations and
> selection.
>
I suspect you're asking me for a mutation by mutation, selective regime by
selective regime, account of how the human digestive tract evolved from a
single-celled organism. I cannot, of course, provide any such thing. I
also suspect that you have neither the intention nor the ability to tell us
how "intelligence" (other, perhaps, than human intelligence) implements any
"design" or change in design in living organisms.
>
> So, okay, we have a simple common ancestor consisting of a single
> functioning cell (and even that is a generous given) that replicates
> (we know not how that started). Take it from there and describe a
> realistic scenario, using factual, scientific observations, as to how
> this single cell develops a digestive system, based on random
> mutations and selection.
>
> Can't do it? Then evolutionists need to be a little humbler about
> their position. To say "We know the digestive system evolved," but go
> silent when the question of "how?" is asked, is to ask thinking minds
> to take your word on faith.
>
Don't be silly, Zoe. It is perfectly possible to demonstrate that something
happened, without having a complete description of how it happened. Your
position is tantamount to saying that if we can't figure out how someone
died, we are not justified in inferring that he is dead.

You have, in the consistent nested hierarchy of homologies, in biogeography,
in vestigial structures at the genetic and morphological level, in the
fossil record, in the jury-rigged and improvised nature of many adaptions
(e.g. Darwin's remark on "similar structures for dissimilar functions and
dissimilar structures for similar functions"), compelling evidence for
common descent with modification.

You have, furthermore, an demonstrated mechanism of mutation and natural
selection. It has produced, in the lab, bacteria resistant to poisons never
found in nature, bacteria that *eat* poisons never found in nature,
multicellular colonial organisms evolved from single-celled ancestors, and
similar examples of striking novel traits. It seems to me that you are not
being asked to accept anything on "faith," but on the basis of considerable
evidence regarding both the fact and the proposed mechanism for it.
>
> So, here we go.
>
> A single cell exists, replicating itself repeatedly. Along comes a
> random "beneficial mutation." What happens next, based on your
> selection principle? How does the digestive system develop?
>
It becomes a multicellular organism.

http://www.gate.net/~rwms/EvoMutations.html

Starting from single celled animals, each of which has the capability to
reproduce there is no sex in the sense that we think of the term. Selective
pressure has been observed to convert single-cellular forms into
multicellular forms. A case was observed in which a single celled form
changed to multicellularity.
Boxhorn, a student of Boraas,writes:
Coloniality in Chlorella vulgaris
Boraas (1983) reported the induction of multicellularity in a strain of
Chlorella pyrenoidosa (since reclassified as C. vulgaris) by predation. He
was growing the unicellular green alga in the first stage of a two stage
continuous culture system as for food for a flagellate predator, Ochromonas
sp., that was growing in the second stage. Due to the failure of a pump,
flagellates washed back into the first stage. Within five days a colonial
form of the Chlorella appeared. It rapidly came to dominate the culture. The
colony size ranged from 4 cells to 32 cells. Eventually it stabilized at 8
cells. This colonial form has persisted in culture for about a decade. The
new form has been keyed out using a number of algal taxonomic keys. They key
out now as being in the genus Coelosphaerium, which is in a different family
from Chlorella. "

Boraas, M. E. 1983. Predator induced evolution in chemostat culture. EOS.
Transactions of the American Geophysical Union. 64:1102.

There are, of course, an immense number of steps along the way: the
development of multiple layers (starting with something cnidarian-like with
two layers of cells, and gradually evolving (in some lineages) a third
layer), the innermost of which may be devoted to digesting food (note that
the single cell, and its simple colonial descendants, already can take in
food through their surface, so what we are talking about here is having some
fraction of the body cells specialize in a function they already have).
>
-- [snip]
>
>>What is your definition of "phenotype," and how does "phenotype" differ
>>from
>>"morphology?"
>
> phenotype has to do with group characteristics, psychological and
> anatomical, resulting from both heredity and environment. It refers
> to characteristics of organisms collectively, or a group of organisms
> having like characteristics.
>
Where did you get this definition? I cannot find a definition of
"phenotype" that limits it to *group* characteristics; most sources define
it as either the physical expression of the genotype, or the observable
characteristics of the individual organism, or simply anything you can find
out about the organism without sequencing its genes.
>
> Morphology has to do with individual characteristics, the form and
> structure of individual animals and plants.
>
-- [snip]
>
>>http://w3.fiu.edu/milesk/genetics.htm
>>
>>Let's take a simple case and question: are chihuahuas and St. Bernards
>>99+%
>>similar in morphology (note that not merely size, but proportions and even
>>toe number may vary between these breeds)? Domestic dogs differ from grey
>>wolves by only about 0.2% of their mitochrondrial DNA (and mitochrondrial
>>DNA mutates faster and is more variable than nuclear DNA, which is what we
>>were comparing with humans and chimps above), so the degree of genetic
>>difference between any two dog breeds must be very tiny indeed. I'm not
>>sure how you'd quantify the difference between, e.g. the St. Bernard and
>>the
>>chihuahua, or a greyhound and a dachsund, but I think you'd easily come up
>>with less than 99.9% similarity in appearance, for all that their genetic
>>similarity can be that great.
>
> nuclear DNA produces morphological similarity. MtDNA has to do with
> energy transfer, not morphological similarities. So why are you using
> MtDNA as an example of morphological similarity?
>
I am not; please read more carefully. I am stating that if mtDNA
differences are so tiny, then presumably nuclear DNA differences are even
smaller, so that two dogs can be 99.8% or more genetically identical, and be
as morphologically different as chihuahuas and St. Bernards.
>
-- [snip]

Let me reargue this entire section (i.e. my assertion that major changes in
DNA sequence can have little or no effect on morphology).

The genetic code (the correspondence of three-nucleotide codons to amino
acids that make up proteins) is "degenerate:" rather than having one codon
per amino acid and one for punctuation, most amino acids correspond to
multiple codons (up to six), and there are three separate stop codons. From
this it follows that one could, in principle, make massive changes (ca. 30%
of the sequence) in the genome of any species without making any changes at
all in the proteins produced or the way the organism grows. This are
"silent mutations" -- they have no phenotypic effects at all. Therefore,
logically, one cannot assume that changes in the genome must translate to
changes in the phenotype at all, much less must map one-for-one onto the
changes in the phenotype.
>
>> Or consider this:
>>there is a gene, Pax-6, which triggers eye development in fruit flies.
>>Humans also have a form of Pax-6 (which controls development of the iris
>>of
>>the human eye), which is not identical to the fruit fly version, but
>>experimenters have induced fruit fly eyes to grow on fruit fly wings by
>>introducing *human* Pax-6 genes into the wings (there are, of course,
>>already fruit fly Pax-6 genes in the wings, but they are deactivated).
>>Evidently, fruit flies could develop normally if some of their genes were
>>replaced by their human homologues, which implies, again, that large
>>changes
>>in multiple genes could have little or no noticeable effect.
>
> I don't know how you can draw such a sweeping conclusion from an
> experiment that shows that fruit fly eyes can grow on fruit fly wings.
> Until you present fruit flies that are reproducing successfully with
> eyes on their wings, how can you say that there is no apparent
> difference in function with these changes?
>
The issue is not whether the flies can successfully reproduce (and the
changes to their wings would not be reproduced; these are aquired traits
that do not affect the germ-line DNA). The issue is whether a a PAX-6 gene
that differs from the fruit fly version can do the same job in cells and
tissues that the fruit fly version can. The fact that human PAX-6 triggers
the same effects as fly PAX-6 argues that the fly version of PAX-6 could
mutate to match the human version, without affecting the way fruit flies
develop. They would neither lose their eyes nor start growing
vertebrate-style eyes. Again, a change to genes would *not* map one-to-one
onto a change in morphology.
>
>> The large
>>variations in sequence between cytochrome-c in various species, together
>>with the similarity in function of the enzyme in different species,
>>likewise
>>suggests that changes in genes don't map one-to-one directly to changes in
>>morphology or behavior.
>
> first of all, you need to demonstrate that these variations in
> sequence are really a result of changes over time and not a result of
> original makeup. It's like an ant looking at the differences between
> a car and a plane and saying, "see these differences? They are a
> result of changes that occurred over millions of years." A second ant
> says, "how can you tell this?" The first ant says, "because, can't
> you see that changes occur as a normal course of events? See here,
> rust builds up on this car, and the fender falls off eventually.
> Therefore, given enough time, the car will end up being a plane."
>
First of all, my argument does not depend on the assumption that the
differences between, e.g. human and pine tree cytochrome-c evolved in the
course of descent from a common ancestor. It depends only on the assumption
that human and pine tree cytochrome-c do the same job, engaging in the same
chemical reactions. If this is correct, a mutation or series of mutations
which did change human cytochrome-c to pine tree cytochrome-c would not
alter the way our metabolisms worked or our morphology. That is, not only
can silent mutations produce, in principle, large changes in DNA with no
changes in phenotype, even non-silent mutations could produce very tiny,
inconsequential changes in phenotype. This was one of the points under
contention.

By the way, even if you don't accept (or, I suspect, understand) the
argument about consistent nested hierarchies as evidence for common descent,
at least you could acknowledge that it has been presented to you. The ant
in your little parable offers no argument, not even a bad one, for cars
evolving into aircraft or for the common ancestry of cars and aircraft (of
course, cars and aircraft reproduce rather differently from living things).
>
>>>> It has been known for a long time (since well before the
>>>>discovery of genes) that tiny changes in developmental rates (e.g. how
>>>>long
>>>>a particular structure continues to grow) can produce immense
>>>>differences
>>>>in
>>>>how an organism looks -- and tiny changes in development rates can
>>>>result
>>>>from tiny changes in genes. OTOH, as noted, large sections of many
>>>>proteins
>>>>(and hence the genes that code for them) can be replaced with completely
>>>>different sequences without affecting function.
>>>
>>> references, please?
>>>
>>The classic examples of small changes in genes producing large phenotypic
>>effects are things like four-winged fruit flies (the rear wings are
>>produced
>>by a single mutation modifying the growth of the halteres behind the
>>front -- and in normal flies, only -- wings), or achondroplasty in humans
>>or
>>dogs (a mutation that shortens the limbs).
>
> and these four-winged fruit flies, do they reproduce successfully?
>
Yes. Why should they not? They don't *fly* very successfully, which is the
usual creationist retort at this point, but they reproduce.
>
>>It is well-known that some homologous proteins between different species
>>are
>>very different in sequence (e.g. the aforementioned cytochrome-c, or the
>>even more widely varying fibrins, while others (e.g. the histones that
>>form
>>the backbones of chromosomes) differ very little between species. And
>>I've
>>mentioned that there are variants in hemoglobin within the human species,
>>some of which don't seem to have much in the way of effects. The
>>inference,
>>of course, is that nearly all alterations to histones prevent them from
>>working properly, while hemoglobin and cytochrome-c can vary much more
>>without affecting function.
>>
>>http://alpha2.bmc.uu.se/~lars/biowww/Proteinevol.html
>
> the mistake made here is to assume that differences in sequence arose
> as a result of external mutational change instead of recognizing that
> beneficial differences were there from the beginning.
>
*boggle* That is not right.
>
>>>> Consider how many genetic
>>>>disorders are the result of changing one amino acid in one protein (the
>>>>result of changing one nucleotide in one gene). Equally drastic effects
>>>>that are not disorders can be produced by equally small changes.
>>>
>>> examples of these equally drastic effects that are not disorders?
>>>
>>Does
>>http://www.hindu.com/thehindu/seta/2002/03/07/stories/2002030700060300.htm
>>count? It involves a mutation that drastically reduces the number of
>>pairs
>>of legs in a species of shrimp, without so far as I can tell actually
>>crippling the shrimp.
>
> so humans have learned how to manipulate the Hox gene to create
> changes. One point for intelligence. How does this support
> evolution? Indeed, do you have evidence that these fruit flies and
> shrimp can successfully reproduce after their genes have been
> manipulated to stop limb development?
>
>>http://www.talkorigins.org/faqs/mutations.html#Q2 has a list of favorable
>>mutations in various species, which would certainly seem to answer your
>>request.
>
> please, not the same old tired list of six examples. In any event,
> what you call favorable mutations, I call inherent ability to vary or
> adapt to environmental stimuli. How are we going to demonstrate which
> is correct? I'm betting there is no predictability test or
> explanatory test that will demonstrate that these responses to the
> environment are really favorable mutations from the outside. However,
> creation theory would predict that favorable adjustments to
> environmental stimuli (what you call favorable mutations) can be
> traced to an internal program that allows for such variations.
>
*boggle* Apparently bacteria have spent their entire history on Earth
(granted, in your view, that's a much shorter history than in mainstream
science's view) hiding untold myriads of spare beneficial alleles (and a
program for calling them forth) in hyperspace, since neither of these show
up when the bacterial genes are sequenced, but the bacteria keep coming up
with really weird beneficial adaptions (why should a bacterium have the
ability to adapt to eat nylon? is this a problem that's likely to come up in
the natural environment?).
>
> snip>
>
>>> so how do you determine whether an adaptation is inherent or a result
>>> of beneficial mutations? You haven't answered that yet.
>>>
>>You weren't asking that question.
>
> I thought I was.
>
>> With bacteria or fruit flies, watching
>>evolution in real time, one can sequence individuals at the start and end
>>of
>>the experiment and spot the mutations.
>
> and how do you determine that what you are observing are mutations
> from the outside or inherent ability to vary, coming from the inside
> of the genetic system?
>
> It's like watching figures morph in a computer program and claiming
> that the changes are a result of random external mutations when, all
> along, the ability to change was programmed into the morphing figures.
> Have you tracked the source of these changes to determine if they are
> external or internal?
>
Personally, no, though as noted some of these bacterial changes have been
sequenced. And, again, what on earth would lead a reasonable person to
suppose that bacteria had a built-in "ability to adapt" (unless that ability
consisted of the potential to undergo random mutations and natural
selection) for, e.g. the ability to digest poisons not found in nature?
>
-- [snip]
>
>>> as long as you are consistently categorizing the same items, whether
>>> books or cars or life forms, you will always get nested hierarchies
>>> for whatever traits are chosen to be used as a categorizing tool. For
>>> any category chosen, you WILL get the same nested hierarchy because
>>> you are dealing with the same category of things.
>>>
>>But pretty clearly ear bones and mammary glands are not the same things.
>>Having hair and having a single (left) aortic arch (as opposed to having
>>two
>>aortic arches like many reptiles, or a single right arch like birds) are
>>not
>>the same thing either. So why, if you create a category of all
>>vertebrates
>>that have three bones in the inner ear, have you also, automatically,
>>created a category of all vertebrates with mammary glands, a single left
>>aortic arch, and fur?
>
> doesn't mean a thing. Why, if I create a category of all cars that
> have four doors, don't I also automatically create a category of all
> cars with windshields, a steering wheel, and wheels?
>
No. You create a category of cars all of which have all those features, but
there are many cars that have those features and don't have four doors. By
the same token, all animals with three bones in the middle ear and mammary
glands also have vertebrae and pelvic girdles, but not all animals with
vertebrae and pelvic girdles have mammary glands and three bones in the
middle ear.

Note, also, that there's a perfectly good reason all sedans have wheels,
windshields, and a steering wheel (i.e. you don't have much of a car without
these features). One can predict, if I tell you my new car has four doors,
that it has a windshield. You can't predict, on that basis, whether it has
a tape player or CD player, or whether the gear shift lever is on the wheel
or on the console between the seats, because those features vary
independently of the number of doors, because they don't depend on the
number of doors. There's no obvious reason why the utility of mammary
glands is greater for endothermic amniotes with three bones in the middle
ear than for endothermic amniotes with only one bone -- but in point of
fact, only the former have mammary glands.
>
>>If I create a category of all cars with automatic transmissions and four
>>doors, that will not the the same as, or entirely contain, or be entirely
>>contained within, a category of, e.g. "all Ford cars with CD players."
>
> because you have created a category that doesn't fit, is all. If I
> create a category of all vertebrates with three bones in the inner
> ear, it will not be in the same category as vertebrates with wings and
> beaks.
>
But why doesn't the category fit? Why, under "creation theory," did the
Creator not bother to create a single feathered animal with three bones in
the middle ear, or a single mammal with a proper avian-style beak?
>
> It's all subjective.
>
No, but thank you for playing.
>
-- [snip of rest]
>
-- Steven J.


.

Relevant Pages