The End of Evolution By Means of Natural Selection

Got it, thanks.

Hi, Faith.If you're feeling overwhelmed, I would be happy to do a Great Debate with you. I usually won't post more than once a day (sometimes less when I have a lot of work to do around the lab), so you shouldn't get overwhelmed with responses.I also like to think I can be reasonable, friendly and patient enough to not get out of line; and knowledgeable enough to understand what you're talking about in population ecology and evolutionary biology.Let me know.Edited by Bluejay, : Subtitle

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-Bluejay (a.k.a. Mantis, Thylacosmilus)Darwin loves you.

I don't know. I'm in a foul mood and I'm surprised I'm still here.If I'm still here start the thread. I have NO idea if I want to do this or what will happen if I do, but start it. Maybe it will at least get me off the madness at this place.I don't really want to "debate" I want to sort things out.

Well, cheer up, you silly girl! It's just a forum, you know...

From reading this thread I get the distinct impression that you need to sort out what mutations are and how they relate to variation. Whether you do this on this thread, on another thread, or in your own research I don't care. However, this does seem to be a big stumbling block where your "theory" is concerned.Perhaps it would help if I describe the problem from the perspective of a biologist. The first thing a biologist runs into when looking at life is the shear diversity of life (i.e. biodiversity). So the first problem is "What makes all of these species different". Starting with Avery it was found that nucleic acids are the molecule involved in heritable traits. Later on Watson, Crick, and Franklin deduced the molecular structure of DNA which allowed us to understand how nucleic acids pass on these traits. As it turns out, differences in nucleotide sequence in DNA is what produces differences between species. The reason that humans are different from chimps is that our DNA sequece is different, by about 2%. The things we have in common with chimps is due to the DNA sequences we share. Commonality in DNA sequence explains the commonalities in phenotype while the differences in DNA sequence explain the differences in phenotype.So how does this relate to DNA mutation? Well, it should be pretty obvious. Mutations change the nucleotide sequence of DNA. Mutations can and do change phenotype. Further observation tells us that every generation has mutations. Every generation is different from the last. The DNA sequence in your cells is unique to you. No other person in the world, past or present, has a genome exactly like yours and this is due to mutation. The only exception is identical twins who are clones of one another.The biologist then has an additional problem to work out. Why do some mutations become more prominent while others disappear? The answer to that is natural selection.The problem you seem to be having is that you ignore the process of mutation. You treat every population as if mutations do not occur.

I'm really really sorry since I know that is the consensus on this thread, that I need to think more about mutations, and because it IS the consensus I will have to do that.But I disagree. What I want to sort out more is the relation of speciation to evolution.

It seems to me that your idea is kind of like saying that road building can't get past a certain point. To demonstrate this you draw maps of a collection of different roads that all advance up ever narrower and steeper valleys until each one dead ends in a box canyon at the foot of a very large mountain. Conclusion: Roads are dead ends that can't take you to all the places you might wish to go.Now the problem is that while you are concentrating on the quality of your map, and arguing about how well it represents each of your chosen roads in turn, other people are building other roads around the mountain. Somebody is digging a tunnel. Someone else just invented the airplane and is going to fly over.Now it may well be that the road in question has gotten narrower and narrower and eventually arrived at an impasse. It may also be that everyone on that road will perish if there is an avalanche.
But there are other roads, and other modes of transportation developing all the time.Right from the first post of this thread: ...you seem to ignore all the other changes that are going on in a given population as the particular allele on which you have focused becomes more uniform in that population. Sure, maybe the population has lost variability with regard to directions that a particular evolutionary road can fork, but other roads, and other ways of getting around the mountain have been developing. When a particularly bad winter comes and no roads are passable, then that tunnel that was quietly being dug is the new reality, and evolution has moved off in a new direction.Sorry you're frustrated. I went through a phase in my life where I made my head hurt trying to reconcile reality with my foregone religious conclusions too. Consider, as I finally did, that you might just be wrong.KP

This, too, is dependent on mutation. Speciation is the result of DIFFERENT mutations accumulating in two DIFFERENT populations. If mutations were not occuring then speciation would not occur. It is analogous to French and Italian branching off from a common root language and acquiring language specific differences over time to the point that people from the two different populations can no longer understand each other even though they share a common root language.

As odd as it sounds, speciation is rather more of an occasional side effect of evolution than anything else. Remember, evolution is simply the change in allele frequency in any given population of organisms over multiple generations. Evolution happens all the time without speciation. It's only when subgroups of a total population are reproductively isolated under different selective pressures that you really see them differentiate to the point where we identify them as new species.If you want to focus on speciation, perhaps you should look into cladistics? It's a modern form of taxonomy, and it's very easy to see how evolution results in an increase in diversity when you look at it a bit.

quote:

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Cladists use cladograms, diagrams which show ancestral relations between species, to represent the monophyletic relationships of species, termed sister-group relationships. This is interpreted as representing phylogeny, or evolutionary relationships. Although traditionally such cladograms were generated largely on the basis of morphological characters, genetic sequencing data and computational phylogenetics are now very commonly used in the generation of cladograms.

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A "clade" is a group of species classifications ("taxa") consisting of an ancestor taxon and all of its descendant taxa. For instance, all vertebrates and their descendants form a clade. All mammals are also a clade, and all members of the mammal clade are also members of the vertebrate clade.What happens in speciation is essentially that a segment of the total population accumulates sufficient differences in their features that we need to identify them specifically rather than simply as members of the whole. A new clade is created, which is still a member of all of the clades the parent population was also a member of (for example, all dogs are still mammals, all mammals are still vertebrates, etc). A "new species" is just a way of saying "a subset of the population that has become sufficiently distinct from the rest of the population that we need to identify it differently so that everyone knows what we're talking about."Is there any part of that that you don't understand? That you disagree with?

It seems that Blue Jay has initiated a thread. If the thread is promoted, then I encourage you to participate. You can treat it as a discussion, rather than as a debate.You can treat it as a way of learning how evolutionists think about how evolution works. You don't have to agree, but it should surely be valuable to better understand the positions you oppose. I think you will find that Blue Jay will treat you fairly, and with patience.

Faith,I recommend that you take this offer. I was going to suggest that you pick someone for a great debate so that the number of replies would be limited to a manageable number better suited to your time.This will allow you to avoid getting posts that come from people you get mad at, and allow you to focus on your issues.You will never accomplish this in the general forum.Peace.

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I assume Faith will be focusing her energies on the new Reduction of Alleles by Natural Selection (Faith and ZenMonkey Only) thread, so we can use this thread for commentary. This is from Message 3 in the new thread: So when Faith wants to add new features to her computer, she deinstalls some software and voil! New features emerge. --Percy

It's what I've been trying to argue all along, Percy. When is it that a trait attributed to a new "mutation" shows up in a domestic breed? Isn't it when the breed is already highly inbred, which allows new (or formerly suppressed) alleles to get expressed? (Many of these new traits are unhealthy as breeders know and have to take into account in choosing mates for their breeds, but sometimes it's a new desirable trait or "mutation") All along I've pointed to domestic breeding as an example of this process where you get new breeds by eliminating the alleles for competing traits. If those alleles remain the selected traits can't get expressed -- or more accurately, there isn't any selection happening, new traits aren't emerging if the competing alleles remain. Selection OF a trait means you are isolating it from competing types and their alleles. I've simply extended this principle to natural selection and the related processes of genetic drift and bottleneck and migration which also isolate a population so that new traits can emerge -- as competing alleles are reduced or eliminated.What I'm so arrogantly and cheekily doing is arguing against the common evolutionist assumption that change simply builds on change in a linear or additive fashion.I'm SURE I'm not getting this said clearly. I'm sure I'm leaving out some essential part of the description and that without it the scientists here can't follow me. But it's not mutations.Edited by Faith, : No reason given.Edited by Faith, : No reason given.Edited by Faith, : No reason given.Edited by Faith, : No reason given.Edited by Faith, : No reason given.

I suggest you focus your energy on the other thread.--Percy

I just wanted to clear this up for Faith's sake. No reply is necessary.In the case of dwarfism in dogs (and in humans) it only requires one copy of the mutated gene. It is a dominant (i.e. not recessive) trait."[Achondroplasia] is an autosomal dominant disease caused by a mutation in the gene that codes for fibroblast growth factor receptor 3 (FGFR3)."
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