Cliff Lundberg wrote:
>I shouldn't have said 'developed', since I was talking about evolution,
>not development. And 'fully' doesn't have much objective meaning.
I was challenging the idea of "you never see a partial wing." Which you
seemed to be saying. In fact, you do. The flying squirrel and flying fish
have "partial" wings. Lungfish have "partial" limbs and so on.
>If the geological record tells you the anatomy of the Cambrian fauna
>arose through the same slow processes of subsequent evolution, then
>nobody's going to convince you otherwise.
well, evidence *is* nice! :-) there's no real reason to believe that things
operated differently then than they do now. What was different? If you have
a number series that goes 1 3 4 5 6 7 8 9 10 are we supposed to believe that
there's no such thing as "2"? or can we safely assume for the moment that
it's just missing?
>>Are we to assume that things "were different back then"? What compelling
>>reason do we have to assume that?
>
>The evidence shows that before the Cambrian, predators were far less
>sophisticated. In this context, radical mutations could have a chance.
I'm not exactly sure what you are saying here. The prey was considerably
less sophisticated also.
>>>Since that creative period, zero new basic body plans have evolved.
>>
>>That's not exactly true. Perhaps you overlooked this:
>>
>>"Our own phylum (which we share with other mammals, reptiles,
>>birds, amphibians and fish) was represented by a small, sliver-like thing
>>called Pikaia.
>>...
>>Especially since that sliver-like thing is the ancestor of frogs,
>>elephants, dogs, ostriches and ourselves.
>
>How can you assert this? Is it because Pikaia resembles a vertebrate
>embryo? No way, you don't believe in recapitulation theory. Because
>they are simple creatures, and vertebrates are complex? No, because
>you know that evolution can proceed by reduction. Is it because you
>can trace the course of evolution from Pikaia to vertebrate in the
>fossil record? No. Is it because you know how it must have happened,
>how Pikaia sprouted segmented limbs etc? No. You're working on faith.
I'm pretty sure recapitulation has been discredited. It is because Pikaia is
the representative of the vertebrates. Few animal fossils left from the
Cambrian are vertebrates. I'm not entirely sure that Pikaia is the only one,
but vertebrates were extremely rare. In the Cambrian nothing yet lived on
the land. There was algae, but no plants and angiosperms (the plants we are
most familiar with) are millions of years in the future. Nope, there's no
straight line of evidence of descent from Pikaia to ourselves, but there
were no (or few) other vertebrates in the Cambrian and *we* are vertebrates.
It's not a huge step to think that maybe we are descended from Pikaia.
>>There were a lot of open niches in the pre-Cambrian that are now filled.
>
>As you say, 'Are we to assume that things "were different back then"?'
ROFL!! touche! :-) yes, in this case. There were no land animals (as far as
I know) not even any land plants. The land was a big open niche.
>Niches are biotic, not geological. No organisms, no niches. I don't think
>there's much point in theorizing about niches in the abstract.
what I was saying is that there were lots of places for new organisms to
exploit that are already being exploited today.
>>It was an explosion, but it took 65,000,000 years to "explode." You said
>>the site seemed "creationistic" but you said that "the quotes are good."
>>I'd like to know why you said that.
>
>Isn't it conceivable that a creationist could put forth something sensible
>or worthwhile? Creationists are free to consider and criticize evolutionary
>theory, more free than those who must argue for gradualism where the
>evidence doesn't support it.
I'm not saying that gradualism is king. As others have pointed out (with
evidence, not just assertions and out of context quotes) evolution proceeds
unevenly.
It is entirely possibly that a creationist could make an actual contribution
to science--and a successful criticism is a contribution--but the dishonest,
decietful quotes on that web page are not it. I could quote Pat Robertson in
such a way that he seems to be a big fan of The National Organization of
Women, but it would be unethical. To even *imply* that he was a huge fan of
NOW would be a lie.
Eldridge was *not* discussing the Cambrian in his quote, Darwin was.
Eldridge was selectively quoted to make him *seem* as if he was discussing
the Cambrian. That's a lie. If creationists have truth on their side, why lie?
Susan
--------
Life is short, but it is also very wide.
http://www.telepath.com/susanb