tronvillain

Oolon::
I seem to recall a couple, but they didn't last too long. Too strong to argue about perhaps?

tronvillain

Unless Burbank preceeded Darwin substantially, it's unlikely that he came up with that "law." It's not entirely incorrect, in that natural selection frequently acts as a stabilizing force, pushing a population towards a local fitness maximum. Also, living thing are bound by existing variation, which could be considered "fixed limiations" except for the fact that mutation is constantly creating new variation.

MrDarwin

Getting back to the nominal topic of "Birds, Stars, Maps and Compasses", I'd like to make the following observations:

(1) Ornithologists understand bird orientation, navigation, and migration to be something that is entirely naturalistic--that is, there are no meddling fairies and no magic involved. Do creationists suggest otherwise?

(2) Bird orientation, navigation, and migration are governed by a combination of genetic and learned factors--again, no magic, entirely naturalistic means. Do creationists suggest otherwise?

(3) Bird species vary in their ability to navigate, and in the means they use to navigate. This variance is entirely naturalistic. Do creationist suggest otherwise?

(4) Individual birds within a species vary in their ability to navigate. This variation is entirely naturalistic--that is, there are no magic fairies manipulating their genes. Do creationists believe otherwise?

(5) Variation in the ability to navigate is passed on from parent to hatchling (whether by generic or learned means)--something long known to pigeon breeders. This inheritance is entirely naturalistic. Do creationists suggest otherwise?

Given that all these components of bird navigation are entirely naturalistic, what reasons would we have to hypothesize that the origin of these components was not natural?

MrDarwin

Ears of corn. They are unlike anything produced by any other species of grass (and in fact their closest relatives, with which they can produce fertile hybrids, lack them).

Thanatos

Stay true to type, as in stay true to species, as in dogs are dogs and horses are horses. As in, a mouse cannot grow feathers - A dog cannot grow wings. For a dog to grow wings, new genetic material would have to be introduced. Can mutations add useful genetic information to a DNA molecule?

The only source of new genetic material in nature is mutations. However, experiments with mutations have not advanced evolutionary theory because mutations only alter the details in existing structures, they do not lead to the creation of new structures. (Rick Weiss, Mutant Mokinker: A Tale of Freaky Flies and Gonzo Genetics, Science News 139, no. 2 Jan. 12, 1991) (Lindsley and Georgianna Zimm, The Hard Life of a Mutant Fruit Fly, Harper's Magazine 284, no. 1703 April 1992)

Mageth

A dog cannot grow wings. For a dog to grow wings, new genetic material would have to be introduced.

Not exactly true. Bats, dogs and dolphins all share a common ancestor. Bats' forelimbs are wings, dolphins' forelimbs are fins, and dogs' forelimbs are legs. All share comparable bone structures (with variations) because they are all based on the same basic design. So "genetic material" for producing the forelimbs of the common ancestor has been modified/adapted to produce three different types of front limbs. Structures which are similar in different species due to the fact that the animals share a common ancestor and the structures are adaptations of a structure of the common ancestor are referred to as "homologous structures."

Mageth

BTW, look at the comparative karyotypes I posted above. It is obvious, even looking at the chromosome level, that a common "genetic material" has been used to produce gorillas, chimpanzees, orangutans, and humans. This becomes even more obvious when one looks at the DNA level. A variation of <2% in genetic code is all that's necessary to differentiate humans from chimps. We're more closely genetically related to chimps than donkeys are to horses! Do you consider chimps and humans as variations of "the same kind"?

[ April 17, 2002: Message edited by: Mageth ]</p>

Quetzal

Thanatos: In your last post you burbled:
Maybe you'll be the very first creationist to ever provide a workable definition of what the blazes is "information" in the context of biology. Please? No other creationist of whom I've ever asked this question has been able to show the relevance of any known concept of "information" to a biological system. Pretty please? Help us out here.

MrDarwin

I'll second that, followed by a question of my own: Thanatos, where do you think the "information" to create an ear of corn came from?

RufusAtticus

Thantos,

Likewise, dogs, horses, zebras, chimps, and humans stay true to type: mammals. They are all mammals and all part of the mammal kind and are related by common descent. Now would you care to defend you classification of kind in a formal, one-on-one debate?

Only creationists think that such situations would be evolutionary. You appear to be oblivious to the claims that individuals do not evolve, populations do.

Maybe you neglected to read my other post to you where I stated: "No scientists claims that evolution ever does produce "new" structures or organs. Evolution only modifies what its got. Sometimes that modification will result in novel features and attributes, such as wings evolving from arms." Hmmm, according to your sources science has actually experimentally supported the view of adaptation gleaned from the fossil record and existing morphologies. Now do you have any sort of evidence that mutation plus natural selection cannot change archaeosaur's scales into feathers over generations, or that a bat's wings are not modifications of the front legs of their ancestors?

Now would you care to answer my previous questions:

Actually, there is much evidence for common descent found in the fossil record and comparative genomics. Would you care to offer an alternate explaination that better explains the oberserved evidence that evolution and common descent?

Do you believe that creatures have existed as immutable kinds with limited evolutionary possibility since the dawn of time? What do you have to support this claim? Can you identify the genetic barrier that establishes this limitation of evolution? What would prevent a population of dogs from evolving so much that they lose diagnostic features and/or gain novel ones? Unless you can show that there is no way for this to happen, you cannot safely say that dogs and cats do not share a common ancestor.

Furthermore, how much genetic change does it take to turn a single cell into a walking, breathing, and voting American?

-RvFvS
P.S. I still have an open offer to debate anyone about the existance of kinds.

[ April 17, 2002: Message edited by: RufusAtticus ]</p>