>We just don't know that there was such a transformation. The possibility
>exists that the scales of L. are independently evolved from some precursor
>of feathers.
>
To me, this sounds a bit like semantics. If longisquama's scales/wing
evolved from some precursor of feathers, then the precursor must look
something like Longisquama's scale. I don't see how this gets you out of
the problem that in these rocks we go from a world in which there was no
feather to one with feathers.
>>OK, where are the complex spines in the fossil record? What animal has
these?
>
>The fossil record is pathetic fragment of history. There must be theory, not
>just to interpolate, but to puzzle out yet unknown processes.
I am really confused now. Surely you aren't suggesting that when we lack
evidence we can make it up are you? If you suggest that feathers came from
complex spines on animals, surely you should be obligated to suggest a
suitable example in the fossil record.
>
>>>I take seriously the principle of reduction and specialization of skeletal
>>>segments. I'd be okay with Ichthyostega as the ancestor of all terrestrial
>>>quadrupeds, if this animal had enough bones in the digits to evolve into
>>>primates, for example, through a process of reduction. But it doesn't.
>>
>>au contraire, it does. THis is from my web page and you can verify what I
>>say in the references there:
>
>I was talking about the number of bones in individual digits, not the number
>of digits. But it doesn't matter much. If it wasn't ichthyostega, it was
>something similar, perhaps a smaller arboreal version.
An arboreal version of a fish in water which is in the process of
transforming into an amphibian? What on earth are you talking about. Are
you toying with my mind?
>
>>I don't think many would argue that we can never know the animals that are
>>directly upon the line of descent. But we can get close.
>
>What is "close?" Either you have a fossil or you don't.
We have fossils that support the idea that feathers came from reptilian
scales. We have no fossils that I am aware of to support your assertion
that feathers arose from complex spines. We also have no arboreal
fish--ever. We do have fish with very tetrapod-like limbs, bone for bone.
We have a fish with fingers. So yes we have fossils to support the
suggested transitions.
>
>>Woah. I didn't say I believe in 'gradual' evolution. I believe that
>>punc-eq is a much better model. It fits with nonlinear systems which is
>>what life is, and it fits the data of paleontology better.
>
>Isn't PE still gradualism? It's mere common sense that there should
>be periods of stasis. There's no real insight into processes here.
No, PE is not gradualism. PE is much more compatible with the HOX genes
which control organismal development. Change a HOX gene and you change the
body form, instantly and over night. ONly 8 genes apparently control the
difference between a monkeyflower which looks designed for a bumblebee and
one that appears designed for a hummingbird. That kind of change is not
gradualism as Darwin envisioned. It is totally different.
>
>>Occasionally things can come back. Dollo's law really is a probability law
>>that says it is extremely unlikely, but not impossible.
>
>What things? Dollo's Law began with observation.
>
>This is all much clearer if one accepts the principle of reduction and
>specialization among serial homologs, that is, among skeletal parts.
It seems to me then, that you are arguing for an evolution from complex to
simple. I suppose then under this view, mankind is the simplest life form
on the planet. Sometimes I agree with this.
>
>If we accept this principle we must posit ancestors with many symmetrical
>segments, whose evolution is a matter of reduction in number of segments
>and distortion of the remaining segments. Obviously, random variation acting
>upon an array of symmetrical elements will produce loss and distortion of
>the elements; random variation generating new symmetrical segments is
>practically speaking impossible.
Not true. you need to look at the nonlinear mathematical systems which
produce wonderfully symmetric patterns yet are produced by chance. You can
see some on my web page (Sierpinski's gasket)
http://www.flash.net/~mortongr/nonlin.htm
glenn
Foundation, Fall and Flood
Adam, Apes and Anthropology
http://www.flash.net/~mortongr/dmd.htm
Lots of information on creation/evolution