unworthyone

Ok so we are in agreement then. Cool. Creationism doesn't fail. How more perfect can you get then taking assimilation of all subject matter in regards to origin of life and then never be proven wrong?

[ April 05, 2002: Message edited by: unworthyone ]</p>

OrderedChaos

Unworthy one seems to be a little confused here.

From what I have gathered from his posts, he thinks that evolutionary biologists think that the butterfly evolves from the larvae to a butterfly. You have it backwards. The larvae stage is the result of evolution that lead to an infant state that was more and more dislike the parent. This trend can be seen in the insects that are alive today.
Let me explain them a little here:
-Ametabolous: These insects undergo no metamorhposis at all. The insects come out of their eggs basically smaller versions of the adult form. Example: Silverfish
-Hemimetabolous: These are basically inbetween metamorphosising insects and non-metamorphosising. They undergo notable changes (most notable being the growth of wings from wing pads), but not to the extent of a full metamorphosis. example: Dragonflies
Holometabolous: Undergo a full metamorphosis. example: butterflys.

So you see, early in the history of insects, all of them were ametabololous. From this line of insects, split off a line that had offspring that were slightly different from the adult. These two lines of insects went their seperate ways, one staying ametabolous, and one becoming the hemimetabolous line. In the hemimetabolous line there were some insects that began to develop a greater and greater difference between the adults and the young. These insects spilt off from the hemimetabolous line to become the holometabolous insects. These insects split off into the many different lineages of insects that can metamorphosis that we see today.

Where is the evidence for this? In the fossil record. The oldest layers of insect history only show ametabolous insects. Above them, are layers that contains both ametabolous and hemimetabolous. Finally the youngest layers contain all the three types. If creationism were true, we would expect that all insects would be present in all layers, but we don't.

What advantage might undergoing metamorphisis have? There are several, but the best in my opinion is seperating the two life stages so they don't compete with each other. The larvae is not compeating with its mother and other adults for food, so it has a better chance of surviving to adulthood.

There is no mutations that cause a larvae to turn into a butterfly, because the butterfly has the same DNA that the larvae did, and vice versa. The larvae carries all the genes it will need to become an adult already in it, the only difference is that it has different genes expressed then the adult form.

RufusAtticus

OrderedChaos,

That was a good reply. I would just like to add the following.

I work with people who work on vinegar flies (genus Drosphila). From my conversations with them I have learned that adult features develop from "imaginal discs" which are areas of undifferentiated cells found in larvae.



<a href="http://www.blc.arizona.edu/courses/181gh/rick/development1/insect.html" target="_blank">source</a>

Although not a butterfly, this is the best known insect in the world.

-RvFvS

[ April 05, 2002: Message edited by: RufusAtticus ]

[ April 06, 2002: Message edited by: RufusAtticus ]</p>

unworthyone

Thank you that was pretty well informative. So how does this combat creationism?

unworthyone

That is good too. Know where I can see a depiction of a fly morphing through the stages?

RufusAtticus

You probably can't find one on the Internet. You might still try <a href="http://www.google.com" target="_blank">Google</a>. I suggest that you do a literature search, like at <a href="http://www4.ncbi.nlm.nih.gov/entrez/query.fcgi" target="_blank">Pubmed</a> or your local library.

It that fails, you best bet is to contact local research univerisites and find someone (prof. or grad. student) who works with Drosophila and ask if you can go by and visit them. Send me an email next week if you can't find anything.

-RvFvS

[ April 06, 2002: Message edited by: RufusAtticus ]</p>

Automaton

"A theory that explains everything really explains nothing."

Say I were to hold the position that evolution is false, and that everything arrived the way it is today by a fantastic occurance of chance. No matter how infinitely improbable this is, it is not falsfiable, and is therefore on the same level as your creationism.

unworthyone

Sounds good to me. My wife was haunted by a "spiritual being" and its not falsifiable, but its still true.
From what claims do you say it is not falsifiable?

[ April 06, 2002: Message edited by: unworthyone ]</p>

Automaton

Huh? <img src="confused.gif" border="0">

unworthyone

Why does something have to be falsifiable for it to be true?

[ April 06, 2002: Message edited by: unworthyone ]</p>