Cellular types is NOT an exception. If you have a better measure of
complexity than cellular types, please present it. But as I see your
argument now, it is merely a case of I won't accept this as a measure with
no suggestion as to what to replace it with. Surely you would agree that
an animals with 200 cell types is more complex than an animal with 2,
wouldn't you?
>
>Me:
>
>>So why haven't sponges and arthropods increased their number of cell types?
>>Are we to think they stopped evolving since they appeared half a billion
>>years ago?
>
>Glenn:
>
>>Let me describe the computer models the authors created. They had 2000
>>different 'beings' each of which could go up or down in the number of cell
>>types with every iteration of the computer. While the maximum number of
>>cellular types continued to go up, the average species didn't go up in
>>cellular types very rapidly.
>
>I'm not easily impressed by virtual reality.
You should be, it is merely mathematics and mathematics describes the very
basis of our universe. Are you not impressed with the math of Quantum
which also could be sniffily dismissed as 'virtual reality', yet all of our
electronics industry is based upon that 'virtual reality'. The math that
allows the plane you fly in is also a 'virtual reality.' It seems that if
you want to be consistent then you must also reject other mathematical
models of reality. Do you do this? Or do you only chose to dismiss math as
it applies to evolution?
>
>>Secondly, if the arthropods and sponges had
>>increased their cell nubmers then they would not be arthropods or sponges.
>
>Really? What makes them so special? Consider again the list you
>posted:
>
>>Porifera 10 cell types 570 myr
>>Cnidaria 14 cell types 560 myr
>>Haemocoelic Bilaterian 30 cell types 560 myr
>>Arthropoda 51 cell types 530 myr
>>Echinodermata, Annelids 39 cell types 525 myr
>>Agnatha 64 cell types 510 myr
>>Cephalopoda 75 cell types 500 myr
>>Actinopterygii 132 cell types 400 myr
>>Amphibia 150 cell types 330 myr
>>Diapsida 154 cell types 300 myr
>>Aves 187 cell types 150 myr
>>Hominidae 210 cell types 5 myr
>
>Notice anything? Porifera, Arthropoda, Echinodermata, Annelida,
>and Cnidaria are all *phyla.* And your list shows that
>much change *can* happen within a phylum, as
>the Chordates go from 64 cell types to 210.
>So why think the other phyla could not tolerate
>such increases in cell types?
Ok, I won't push that point. But then on the other hand, you can't claim
then that this doesn't represent an increase in complexity with time. You
are using a lot of smoke and mirrors to avoid the clear fact that EVEN
WITHIN THE PHYLA CHORDATA THERE HAS BEEN AN INCREASE IN COMPLEXITY WITH
TIME. And if, as Art suggests that the modern arthropods are more complex
than their ancient counterparts, then it would equally imply that
complexity has increased over time. That was the point of my post--that
complexity has increased. Nit pick the details if you want, but that
doesn't get you around the fact that observationally the maximum number of
cellular types has increased with time.
Either there is
>something unique (perhaps special) about chordates
>and/or verterbrates, or the authors of this article didn't
>do their homework by representing phyla with
>species data.
I think you are being inconsistent. You wrote yesterday:
>So why haven't sponges and arthropods increased their number of cell types?
>Are we to think they stopped evolving since they appeared half a billion
years
>ago?
As you correctly point out, they probably did increase their maximum
complexity over time. In which case, one would be forced to conclude that
the arthropods and sponges probably had a lesser number of cell types in
the past--which then goes straight to my point that complexity has
increased over time. You can't have it both ways.
>
>>Populations of fish that did evolve are now called amphibians,
>>reptiles, birds, mammals etc.
>
>Yes, 5 data points against a backdrop of thousands where no
>significant increase is seen. And you call this a trend?
Mike, you made my point for me by suggesting that in the past sponges and
arthropods had fewer cells--or at least by criticising the concept that
their cell type was constant. But remember the other factor in all this is
what I told Art. Their are fitness maxima which are quite strong and thus
a population can get trapped into a region on the fitness topology in which
it is difficult to get out. In such a case, they would stay constant in
number of cell types. Your critcism in part is based upon the idea that
evolution MUST change things. THere is no requirement that animals MUST
evolve to superior beings. There is only the opportunity. You
misunderstand evolution at this point.
glenn
Foundation, Fall and Flood
Adam, Apes and Anthropology
http://www.flash.net/~mortongr/dmd.htm
Lots of information on creation/evolution