Re: Defense requested
- From: John Harshman <jharshman.diespamdie@xxxxxxxxxxx>
- Date: Sun, 18 Sep 2005 14:20:25 GMT
Zoe wrote:
> On Tue, 13 Sep 2005 23:15:37 -0500, "Steven J."
> <sjt1957NOSPAM@xxxxxxxxxxxxxxxxxxxx> wrote:
>
>
>>"Zoe" <muze10@xxxxxxx> wrote in message
>>news:hutei1tmkbcgusbbrt2tqctapaq5hqsn4r@xxxxxxxxxx
>>
>>>On Sun, 11 Sep 2005 22:36:27 -0500, "Steven J."
>>><sjt1957NOSPAM@xxxxxxxxxxxxxxxxxxxx> wrote:
>>>
>>>snip>
>>>
>>>zoe wrote:
>>>
>>>
>>>>>Question for Steven J.: Why is inheritance combined with selected
>>>>>mutations considered sufficient evidence for relationship through a
>>>>>common ancestor? Inheritance is observed to be a process in which the
>>>>>characteristics of the ancestor is passed down to offspring, resulting
>>>>>in recognizable copies of the ancestor. That is why apple trees
>>>>>always bear apples and orange trees always bear oranges. Chimps
>>>>>produce chimps. Birds produce birds. Lizards produce lizards. This
>>>>>copying process is observed to be the rule, not the exception.
>>>>>Morphing from one species to another is not observed to be a rule --
>>>>>indeed, not even an exception. So why is the "mechanism" of selected
>>>>>mutations made to carry so much weight when it has never been observed
>>>>>in as clear a manner as that of kind producing kind?
>>>>>
>>>>
>>>>First of all, you are of course wrong. Speciation has been observed, in
>>>>the
>>>>lab, in the field, and in the fossil record.
>>>
>>>first of all, can we be absolutely clear about what you mean by
>>>speciation? I agree with you that speciation has been observed --
>>>variations within a species, yes. But if by "speciation" you mean new
>>>life forms that have been OBSERVED to descend from ancestors that are
>>>now so different that they no longer can be classified in the same
>>>genus, then, no, that kind of speciation has not been observed. It is
>>>still in the realm of speculation.
>>>
>>
>>By "speciation," I of course mean "speciation."
>
>
> question: What is speciation? Answer: Speciation. Right on,
> Steven.
That was exasperation talking. You can't even be troubled to learn the
common definition of a term you use constantly.
>>Cladogenesis. One species
>>splitting into two species.
>
> please be more precise. Does this one species split into two species
> that are so radically different that they could be classified into
> different genuses?
That's "genera", and the answer is maybe, maybe not. The degree of
difference is not relevant to the question of speciation. It's
reproductive isolation that counts.
> Or do you mean that if a species shows variation
> such as a shorter beak or a longer beak, that this difference
> immediately puts them into the category of a new species?
No, he doesn't. Populations can change without speciation. If two
populations become reproductively isolated from each other, with no
morphological change that we can see, they are nevertheless separate
species.
> I am questioning that part of your theory that hypothesizes that, for
> instance, birds came from dinosaurs. If I ask for evidence of this
> kind of evolution, and you respond with, "See, this species has a
> slightly different tail length than its parents," then you have not
> answered my question. You have simply supplied an inadequate example
> to prop up a weighty proclamation.
But that's not the evidence he would use. He would point you, once
again, to the nested hierarchy that only arises from common descent.
If you're asking for a videotape of a dinosaur morphing into a bird, you
will always be disappointed. But we don't need one to know the history
of these groups.
>> It is no part of the definition that the new
>>species has to be different enough to be classed in a new genus.
>
> oh, so until they arrive at the point where they can be classed in a
> new genus, they could rightfully be considered variations of the same
> species?
No. Only by your personal definition. The majority of genera have more
than one species in them. Some genera have hundreds of species. Perhaps,
by your definition, they aren't really species. We have no way of
knowing. If we take you literally, then "species" to you means "genus".
So why not say "genus" instead of "species"? I think you have no real
idea what you mean.
> In other words, you have not yet provided evidence other than to ask
> me to accept your word that these small variations MUST some day,
> millions of years down the road, become something that belongs to
> another genus. Should I accept your word? Would you recommend that
> your children accept the word of anybody who presents that kind of
> evidence?
Please try to separate the definition of one simple word, species, from
assertions of evolution. Just accepting the common definition doesn't
mean anything about new genera. However, what you describe does indeed
happen. You have been shown considerable evidence for it, in the form of
that nested hierarchy. Humans and chimps share a common ancestor. They
belong (at least according to traditional classifications) to different
genera. There you are.
Your defense is to claim that the hierarchy is arbitrary, and depends on
careful choice of characters. Our rejoinder has been to pick a set of
characters at random from the genome and, though objective and even
experimentally blind methods, to arrive at the same tree every time.
When are you going to notice this?
>>How could
>>it be? There is no fixed amount of difference which requires or justifies
>>placing two species in different genera.
>
> are you saying that evolution is unobservable and unsupportable?
No, he's saying exactly what he said. The term "genus" is an arbitrary
label for some group of species that all share a common ancestor, that
is a label for some node on the phylogenetic tree. But we could move
that label up or down the tree, to include fewer or more species,
because the label is arbitrary. The tree, however, is decidedly not
arbitrary. Similarly, the computer I'm typing on now is a real entity. I
call it a computer, but I could just as easily call it a difference
engine, or an electronic brain, or a wiffle ball, or a gazank. It's just
an arbitrary label attached to a real thing. See how that works?
>> At the purely genetic level,
>>humans, chimps, and gorillas (which are usually placed in three separate
>>genera) are as similar as many sets of species (e.g. the horses, zebras,
>>donkeys, etc. that make up _Equus_) that are placed in one genus. At the
>>morphological level, you can find as much difference within some single
>>species (e.g. _Canis familiaris_) as you find between species that are
>>sometimes placed in different genera.
>
> we have barely begun to play in the shallows of the genetic ocean.
> Conclusions set in concrete would be as arrogant as picking up a shell
> from the seashore and expounding on all marine life, based on the
> empty shell. I think I would like to wait before jumping on such a
> bandwagon.
You, talking about arrogance? Hah. We have enough evidence right now to
refute every one of your claims. Don't hide behind the supposed current
ignorance of science.
>>Your argument here depends on a principle (if we haven't directly observed
>>something, we have no grounds for inferring it has happened) that would lead
>>us to doubt, e.g. that the planet Pluto actually orbits the sun (its orbital
>>period is longer than the time humans have known the planet existed), or
>>that atoms exist.
>
> that is not the principle upon which my argument is based. But since
> you bring it up, how about turning that argument in the direction of
> an unseen Creator? If you haven't directly observed the Creator, does
> this mean there are no grounds for inferring His existence?
No, it doesn't. But it doesn't mean that you do have such grounds
either. That depends on the actual evidence, and that's what we're
trying to talk about here.
>>Another note: "variation" refers to the differences among individuals within
>>a species at any given point in time. That some human beings have blue
>>eyes, and others brown, is an example of variation. By that I do *not* mean
>>that eyes started out one color, and other colors evolved (although I think
>>that happened); I mean simply that that is one sort of difference that
>>exists right now among humans. "Variation" is not evolution, "micro,"
>>"macro," or "middle-sized." Evolution means that some variants become
>>commoner, and others rarer (and new variation can arise through mutation,
>>which, of course, is a case of a variation becoming more common --
>>increasing from 0 to some higher frequency). Finch beaks becoming bigger
>>over time is not "variation," but "microevolution."
>
> well, I don't quite follow you. Earlier you say that variation is
> speciation. And speciation, I gather, is your explanation for
> evolution. So why do you now say that variation is not evolution?
He never said that variation is speciation. That was some
misunderstanding on your part, somewhere. Nor is speciation his
explanation for evolution. It's one part of evolution. It's not clear
just how you are confused here, or I would try to help more. But you
have clearly not understood most of what Steven said.
> Instead, you are now saying that if a variation becomes commoner and
> others rarer, then evolution occurs. So apparently, evolution doesn't
> have to do with mutations, per se, but rather, with concentration of
> genetic traits within a gene pool through narrow interbreeding, or
> broadening of genetic traits within a gene pool due to interbreeding
> more widely. If so, then that kind of limited evolution would be
> acceptable to this creationist.
No, that's not what he's saying. Mutation is commonly not considered, by
itself, to be evolution. The common definition is "changes in allele
frequency in populations". I have no idea how you got from there to
"narrow interbreeding", etc. The simplest way for allele frequencies to
change is for organisms with different alleles to have different amounts
of breeding success.
> snip>
>
>>>who decided that humans were primates? Why, humans, of course --
>>>based only on similarities that parallel on the genetic and
>>>morophological areas, and not because apes have been observed to give
>>>rise to humans. Anyone can decide that Species X is a primate due to
>>>similarities, and then announce that because Species X is now
>>>considered to be a primate, that therefore, primates gave rise to
>>>Species X.
>>>
>>
>>All classification systems depend on similarities and differences, of
>>course. *If* we explain the nested hierarchy of life through common
>>descent, then, of course, placing a species within a clade represents a
>>judgment that it is descended from same LCA as other members of that clade.
>>But originally, humans were placed in primates without any judgment that
>>"primates" were related by ancestry.
>
> exactly. Primates originally were grouped according to the
> characteristics of mammals, not because they were supposed to be
> related. The relationship concept came later.
Precisely. Relationship is the explanation for the observed hierarchy.
We're back to nested hierarchies being non-arbitrary. Can you think of a
different explanation than common descent for this?
>>Note that we have never observed Asian human populations giving rise to
>>American Indians. We have never observed Malaysian populations giving rise
>>to the Polynesian peoples. We have never, in point of fact, observed all
>>modern human populations rising from a single population (and it was a
>>staple of a certain sort of racist antievolutionist a century back, that
>>we've never observed a white couple giving birth to a black child, or
>>vice-versa; no "race" has ever been observed to arise from another). Your
>>argument, here, can be extended in directions I am sure you would not like
>>to take it. Our assumptions of the common ancestry of humans and the
>>pattern of past human migrations and colonization are heavily dependent upon
>>the same sort of analysis that leads us to conclude that all primates share
>>a common ancestor.
>
> please note that you start with unfounded assumptions that all
> primates share a common ancestor, and then use that as a platform to
> form assumptions of the common ancestry of humans.
Don't worry, that's all based on real data too. No assumption is needed.
It's data all the way down.
>>>>Third, humans and chimps, or humans and gibbons, *are* recognizable copies
>>>>of the ancestor.
>>>
>>>hold up. Recognizable copies of which ancestor? The last common
>>>ancestor of all chimps, humans, and gibbons? Please present this
>>>ancestor for inspection so we can compare and see if humans are a
>>>recognizable copy of this ancestor.
>>>
>>
>>Zoe, we don't even have fossils of the last common ancestor of all modern
>>humans (_Homo sapiens sapiens_). If you're going to demand that I show you
>>a specimen before you acknowledge that there is sufficient evidence to infer
>>an ancestor, then kiss goodbye to Adam and Eve, or any other ancestral
>>population of all modern humans. We cannot prove that any fossil has any
>>descendants today, even if we identify that fossil as our own species (there
>>are humans who die childless, and ethnic groups that go extinct). So we
>>cannot show even that all humans are "recognizable copies of this [last
>>common modern human] ancestor."
>
> then please don't say that humans and chimps are recognizable copies
> of the ancestor. To have a recognizable copy, you have to have the
> original. If you claim that we are recognizable copies of our
> ancestor, it sounds as if you know what that ancestor was like in
> order to "RECOGNIZE" the copy. I would suggest that instead of
> backing away from your poorly phrased statement, and resorting to
> apologetics, it might be better to just admit that your statement was
> incorrect.
Sigh. We can know quite a lot about the common ancestor based on its
descendants. Especially about its genetics. If you think that all humans
had a common ancestor, please show me that ancestor, or retract your
claims about what we can't know.
>>>> We share the
>>>>large brains, the forward-staring eyes, the orbital bar rather than a
>>>>shelf
>>>>of bone connecting orbit to skull, etc. I'm sure you recall the shared
>>>>GULO
>>>>pseudogene in humans and other apes and monkeys; this is merely one of a
>>>>host of pseudogenes and endogenous retroviruses we share in common. Then,
>>>>of course, there are the sequence similarities in coding DNA. That's the
>>>>whole point: we look like one another; the nested hierarchy of homologies
>>>>is
>>>>a family resemblence.
>>>
>>>there you go again. We look like one another -- the similarity factor
>>>again. Since when is similarity sufficient evidence to determine
>>>relationship?
>>>
>>
>>Does the phrase "paternity test" mean anything to you?
>
> is a paternity test used for checking if chimps and humans are
> related?
Something similar in many ways. But he was merely using a different
example to point out the fallacy of your claim.
>>I'd go into more detail about how the similarities of different primate
>>species are demonstrably unnecessary and inexplicable from a design
>>standpoint, but explicable and expected from a common descent standpoint,
>>but then I'd run into your theory-phobia again.
>>
>>>>Really, Zoe. It's all very well to go about saying "apple trees always
>>>>bear
>>>>apples," but you ought to note the great variety of apples that have been
>>>>bred.
>>>
>>>I agree with you that there is variation within a species. But those
>>>variations are still apples. Some may tire of this answer, but it is
>>>a valid objection and should be taken into consideration.
>>>
>>
>>No it isn't, and no it shouldn't be.
>
> okay. Yes, it is, and yes, it should be. How's that for getting
> somewhere.
>
>
>>>> Of course, this is less spectacular than the great variety of
>>>>_Brassica oleracea_ (brocolli, brussels sprouts, and cabbage are all
>>>>varieties of this one species). Sometimes you have to look rather closely
>>>>to recognize all these as copies of the same ancestor. And, as long as
>>>>you're looking closely, you might as well see the characteristics of
>>>>shared
>>>>ancestors in the various primate species.
>>>
>>>how can this superficial approach appeal to the rational, thinking
>>>person? You're still doing the "looks like" exercise.
>>>
>>
>>You are concerned about rational, thinking persons? Have you actually met
>>such people, or merely heard of them?
>>
>>Your argument here, as I noted above, is a flat denial that we can know a
>>thing that we have not witnessed directly.
>
> that is definitely not my argument. I talk about a "looks like"
> approach and you diverge to a "not witnessed directly" approach. How
> did that switch happen?
It's clear from many things you have said. You constantly ask for us to
show you a dinosaur transforming into a bird, or to show you the common
ancestor of chimps and humans, as if only this direct witnessing is valid.
> But since you've brought it up, do you deny that we can conclude a
> Creator without witnessing Him directly?
No. In principle. However, it all depends on the evidence itself.
>> You hold this view
>>inconsistently, of course, which means that you accept some results of
>>science (those that agree with your theology) and arbitrarily reject others
>>that disagree with your theology. Personally, I'd advise you to revise your
>>theology, but alternatively you could simply consistently admit that you
>>don't have a theory of creation, that your viewpoint is incurably hostile to
>>the very idea of theory, and that science and its results do not interest
>>you.
>
> I will admit to no such thing, Steven. You're trying to put words in
> my mouth.
>
> I am 100 percent in support of real science and the theories of
> science. Evolutionary hypotheses are not science, and should not be
> foisted on an unsuspecting public as true science.
Why?
>>>snip>
>>>
>>>>Inheritance makes it easy to distinguish you from me. Does that mean we
>>>>share no common ancestors?
>>>
>>>you are talking about a single species or group -- human beings. Of
>>>course there is a common ancestor pair for humans. Just as other
>>>groups have their common ancestors.
>>>
>>
>>Please provide me the evidence that there was ever a common ancstor pair for
>>humans.
>
> trace back as far as you can, and there is always a common ancestor
> pair for humans. Why should it suddenly change somewhere back in the
> mists of time?
So you don't have to actually observe common ancestors to know that
common ancestry exists, right? Good. So how do you know that humans have
a common ancestor, but chimps and humans don't? Remember that you reject
the notion that you have to see something happening before you can know
it happened, so don't try any argument of that sort.
.
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