Evolution vs. Creationism

AmbianceMan wrote: Regarding the wolf to dog video.  This actually goes against your theory of evolution and is used in the creationist argument.  (But you already knew that I'm sure)   You do realize that there is no species change here right?  Micro-evolution is a fact, we see it, we breed it.  But not species differentiation (macro-evolution).  These are highly different.  Breed a bird into a velociraptor and I'll be impressed.   I believe the only "evolution" happening is de-evolution or devolution depending on who you ask.  In order to breed animals such as dogs or horses, you "breed out" bad genetic information.  You are not "breeding in" better information.  So in each case we are talking about genetic information being lost.  Nothing is gaining genetic material, only losing.  (Detractors paste your wikipedia link here, we know how reliable they are) So I postulate that humans are less intelligent and less healthy than when man began.  That's why we have so many imperfections, crooked ears, asymmetrical faces, more cases of cancer, DNA anomalies.

^ I understand all that, and it makes sense to me (I agree). I still don't find it necessary to use it to confuse people who are trying to understand the concept of evolution. I think that only very, very few people would, if told the principle of evolution by natural selection, scratch their head and miss that factor? What I'm trying to say is that genetic drift is not necessary to be explained in detail during a introduction of the theory of evolution.

^ it seems like you're saying that in order to claim to be a scientific thinker, you *always* have to be splitting hairs and mention every little detail. I strongly disagree about that. It would mean that I would have to study biology in excruciating detail before I would be allowed to even begin talking about natural selection.

And about the bird example: Natural selection explains why there were dinosaurs and birds. Genetic drift might explain why the birds (or bird ancestors) "suddenly" had an advantage and pretty much replaced the dinosaurs, but without natural selection you would neither have dinosaurs nor birds. Genetic drift is a secondary mechanism that, no matter how strongly, only influences the course of evolution, to which the driving, "guiding" force is still natural selection.

BTW: Of course you'll always have both. Natural selection is not something that could be taken out of the equation ... except for us humans maybe, since we are the first animals on this planet who are capable of planning ahead, and tweak our chances for survival. It remains to be seen whether we're clever enough to use that power though ...

Negoba wrote: Mr ProgFreak wrote: ^ That's a relief, since it's not such a big help in explaining how evolution could have achieved complex forms of life like humans - is it? It can explain how some branches of the tree of life became extinct or others were favored, but it doesn't explain how those that were favored continued their evolution. To explain that, you need natural selection. EDIT: Actually such a cataclysmic event could even be seen as an (extreme) case of natural selection - if the term was used in a slightly broader sense.   First of all, I already made your EDIT point. But I could also call it Unnatural selction if I chose.   Second, I never said the natural selection in the stricter sense was not a factor in evolution, just that other factors are at least equally important.

That's where you're wrong IMO. Remove natural selection and it all collapses like a house of cards. Do you really think that life could have evolved with only "random selection"?

Negoba wrote:   You keep saying that the more complex aspects of evolution have nothing to do with the debate. In fact, they are very important because you are making an argument of exclusion.

I am saying that details like genetic drift play a minor role compared to natural selection. And if you disagree - fine, but please don't make it appear like that would have anything to do with scientific consensus. Name one respected biologist who would agree with you that genetic drift is such an important factor in evolution that you can't possibly leave it out of a discussion with laypeople (or Creationists, which is about the same thing ;-)).

Dean wrote: Mr ProgFreak wrote: ^ no problem at all ... what bothers me more is that this is totally off topic and unnecessary to understand the principle of evolution by natural selection. I'm really annoyed by how Negoba is systematically trying to complicate the matter. "Willful Obscurity", I think that's the term Dan Dennett used in a similar situation. Well, one of the reasons is to equip all evolutionist with an arsenal of knowledge to combat the criticisms from the creationist/ID lobby, this includes discussing all evolutionary mechanisms even if only among ourselves, so when they come up with some example where natural selection appears to fail such as those mutations that do survive but are not necessary for survival (like hair colour), we can point to one of the other mechanisms that does explain it.

You picked a bad example though with hair color. Hair color is connected with skin color, and that actually serves a purpose. Maybe today to a lesser degree, but still.

I don't see how knowing about the details of genetic drift would help against Creationists though - they are not taking evolution seriously anyway. Just look at the latest posts of AmbianceMan -  I think I remember that at one point he said he was not a Creationist, but now he's using their typical arguments, and they are so twisted and non-sensical from a scientific standpoint that problems like genetic drift are "pearls for swine". Such details are IMO more suited for people who have already accepted the key element to for example understanding how - through evolution - a bird could have evolved from a reptile. Which is a well documented example, and a number of intermediates have been found. To explain this process, natural selection is much more important than genetic drift (in my humble laypeople opinion).

Dean wrote: Mr ProgFreak wrote: ^ no problem at all ... what bothers me more is that this is totally off topic and unnecessary to understand the principle of evolution by natural selection. I'm really annoyed by how Negoba is systematically trying to complicate the matter. "Willful Obscurity", I think that's the term Dan Dennett used in a similar situation. Well, one of the reasons is to equip all evolutionist with an arsenal of knowledge to combat the criticisms from the creationist/ID lobby, this includes discussing all evolutionary mechanisms even if only among ourselves, so when they come up with some example where natural selection appears to fail such as those mutations that do survive but are not necessary for survival (like hair colour), we can point to one of the other mechanisms that does explain it.

Edited by AmbianceMan - December 06 2009 at 22:59

I will continue to systematically try to complicate the matter.

Mr ProgFreak wrote: ^ no problem at all ... what bothers me more is that this is totally off topic and unnecessary to understand the principle of evolution by natural selection. I'm really annoyed by how Negoba is systematically trying to complicate the matter. "Willful Obscurity", I think that's the term Dan Dennett used in a similar situation.

I have to disagree with you here. Genetic drift is a powerful force in evolution. Unfortunately, Dawkins (and Coyne, to some extent, I believe) fall closer to "adaptationism" - the idea that natural selection can explain nearly everything of an organism's phenotype.

As far as I can tell, we currently do not know exactly how powerful drift is. We know it's incredibly important at the molecular level (neutral theory), but how this interacts with the phenotype is still a bit unclear. One example of the effects of drift is the fact that Native Americans all have an O blood type. (I haven't personally investigated this but it's an example I see often.)

One author, Michael Lynch, believes that most of the genomic architecture of eukrayotes can be explained by non-adaptive processes (paritcularly, drift). He believes that introns/exons, transposons, repetitive sequences, etc. are due to processes that are not natural selection.

This isn't a needless topic.

(Right now, I'm planning on writing a paper and presenting a seminar (undergrad senior seminar) about this very topic: What are the relative roles of natural selection and genetic drift in explaining the history of life? Or something along those lines at least. I'm still early in the research part though, so I can't give you a bunch of examples as to how important drift is. )

^ no problem at all ... what bothers me more is that this is totally off topic and unnecessary to understand the principle of evolution by natural selection. I'm really annoyed by how Negoba is systematically trying to complicate the matter. "Willful Obscurity", I think that's the term Dan Dennett used in a similar situation.

^ That's a relief, since it's not such a big help in explaining how evolution could have achieved complex forms of life like humans - is it? It can explain how some branches of the tree of life became extinct or others were favored, but it doesn't explain how those that were favored continued their evolution. To explain that, you need natural selection.

EDIT: Actually such a cataclysmic event could even be seen as an (extreme) case of natural selection - if the term was used in a slightly broader sense.


Edited by Mr ProgFreak - December 06 2009 at 17:34