Originally posted by Mike_A
The change in genetic information in an organism followed by its spread through a population due to natural selection is evolution. It doesn’t matter if speciation happens or not; that by itself is still evolution.

Yes. It is an evolution of the species. It is not, however, Darwinian evolution. I agree fully that species is changing, whether there is speciation or not. Where I will disagree with you is that the mouse species is going to eventually become something other than a mouse, which is what Darwin suggested would eventually happen.

Natural selection is a kind of evolution. It is a very small change, or Microevolution. No amount of small changes will ever amount to Macroevolution.

I don’t get what you mean. Do you mean that you would just say it was down to hybridization and therefore not speciation?

That doesn’t make sense. If the resulting organism ticks all the boxes to be considered a separate species, as the observed instances do, then it’s speciation regardless of whether it came about via hybridization.

I’m also not sure how you dismiss the Goatsbeards flower so easily. The pre-existing species were known and tracked when introduces, instances of hybridization were observed and recorded and found that they were unable to sustain a viable population by themselves; thus not a separate species. However additional hybrids were found that were capable of sustaining viable populations within their own group but could now not do so with members of either parent species; in other words the new plant constituted a new species and speciation was observed to have occurred.

Originally posted by Mike_A
I don’t get what you mean. Do you mean that you would just say it was down to hybridization and therefore not speciation?

That doesn’t make sense. If the resulting organism ticks all the boxes to be considered a separate species, as the observed instances do, then it’s speciation regardless of whether it came about via hybridization.

I’m also not sure how you dismiss the Goatsbeards flower so easily. The pre-existing species were known and tracked when introduces, instances of hybridization were observed and recorded and found that they were unable to sustain a viable population by themselves; thus not a separate species. However additional hybrids were found that were capable of sustaining viable populations within their own group but could now not do so with members of either parent species; in other words the new plant constituted a new species and speciation was observed to have occurred.

I didn't dismiss it. My point was that just because the variants weren't known prior to being found, does not mean unequivocally that they didn't ever exist. And I also do have this problem:

Hybridization in either the goatsbeard example or the wolf/dog example creates a new species SOLELY based on the fact that the separate strains of goatsbeard and the wolf versus the dog have been placed as separate species by a person....based, I might add, on pretty shaky logic. For instance, the whole reason the dog and the wolf can procreate are because they have the same number of chromosomes, right? And I think we can argue that two species of goatsbeard, are just almost alike (i.e. they're both weeds with the same genetic make-up only slight variants withint that make-up).

I can't get past the fact that the only difference I see between a wolf and a dog is that the dog was once a wild creature of the same group as the wolf - in fact, it probably was a wolf - that has gone through centuries of domestication-induced adaptation and forced cross-breeding of other members of the same group also going through domestication-induced adaptation.

And I can't get past the fact that one strain of goatsbeard is almost just like the other strain of goatsbeard and basically the same weed with slight variations - also probably resultant of adaptation....but they are the same weed.

Do you not agree that caucasians, africans, and asians are of the same species only we have evolved through adaptation into slightly different strains of the same species? I haven't got the newsletter if they have put us into different species yet - let me know if I'm behind on my news. And as far as I know the offspring of any pairing between said groups has not been deemed to be a separate species either - even though they are also a different strain due to slight genetic variations.

This is the main problem I have with the biologists...they don't stay consistent. They're entire Kingdom to Species structure is fraught with inconsistencies and sometimes just downright guesses that the best answer you can get from them is - uhhh, we just decided to put it there???

I have no problem accepting that evolution takes place. I have no problem with it, because I'm not blind. And you'd have to be blind, and real dumb - in a stupid kind of way - to not see that it naturally occurs. What I have a problem with is the extrapolation of the word "evolution" to an extent that it becomes a faith-based system in which, when you get to major gaps, inconsistencies and downright unsubstantiated leaps of faith, you are asked to just accept it. Kind of a "just trust us on this" approach.

Evolution takes place intra-species...period. We have real-life examples of it taking place through adaptation, and hybridization. Hybridization, however, only results in speciation due to human classification...which is highly subjective and inconsistent. It is my contention that the evolution that takes place within a species due to hybridization is nothing more than that - I do not agree, speaking to the two examples we're discussing here - that it is true speciation. Not if a consistent hand is applied to the classification structure. In other words - I would call the wolf and the dog subspecies or strains of the same species. Just as I would call an African and Swede subspecies or strains of the same species. It's consistency I'm looking for.


[edit on 8-30-2009 by Valhall]

I didn't dismiss it. My point was that just because the variants weren't known prior to being found, does not mean unequivocally that they didn't ever exist.

But this has happened in the lab under controlled conditions. Even if it resulted in a species that exists outside the lab it would still be an observed instance of speciation.

In the case of the Goatsbeard, the original populations were introduced IIRC in the early 20th century. Europeans had been on the continent for a few hundred years prior and the Native Americans even longer so the existing wildflower population was well known. What you are suggesting is that a flower existed that was remarkably like one found thousands of miles across an ocean at even the genetic level; and that despite thousands of years of human habitation this was never discovered until the exact moment that two populations of these foreign species met and that it was found in the exact location that these two populations met and that it shared morphological and genetic similarities to both of these foreign species. That’s one hell of a coincidence!

Hybridization in either the goatsbeard example or the wolf/dog example creates a new species SOLELY based on the fact that the separate strains of goatsbeard and the wolf versus the dog have been placed as separate species by a person....based, I might add, on pretty shaky logic.

It’s a fair to make the point that species, genus, family etc are all somewhat fuzzy; these are really categorization problems. The observed changes still happen.

But even if you disregard the categorization of new species my question a few posts above still makes sense. We both accept that organism populations can change in morphology due to genetic variation, if these changes occur many times over a long period why can’t they produce an organism that is radically different in both genetic and morphological make up? A mouse like creature producing a dog like creature for example? Even throwing speciation out of the window nothing has to happen that we both don’t already agree on. We see this happening in the fossil record.

What you say about wolf and dog breeding suggestion you’re a little confused about their classification. Dog is not a separate species, it is in fact a separate subspecies as you say at the end of your post. The difference being that a different species would not, due to genetic differences, be able to produce a viable population with another species. Subspecies also will not produce a stable population but this is due to non genetic factors.

Therefore wolves and dogs can breed but would not do so naturally and therefore dog is a subspecies of wolf.

The new species of Goatsbeard is incapable of producing a stable population due to genetic differences and is therefore a new species. This is regardless of how the new species came about (hybridization or not).

Similarly in humans, black Africans and white Europeans aren’t different species or even subspecies because put together they will produce a stable population.

I think the consistency you’re after is better than you give it credit for.

Yes, but they were not always. And I believe yet another wrong will be righted the same as that one when the hard-headed biologists give in after too much time and effort and is applied to get the coyote in the same species as well. Because, just as with the wolf, they will have to answer the onerous questions surrounding the breeding of coyotes to dogs and be unable to satisfactorily defend their subjective classification into different species.

Those questions will be:

breeders of coyotes and dogs can take a female coyote, breed with a male dog and get a half-breed between these two species.

they can then take the offspring and continue to breed them to a full coyote until they have reached 99+% coyote.

What is the classification of the resultant "thing"? And at what point along the iterative breeding process does the "thing" switch from one species to another??? This is the same problem they had when they had the wolf and dog in separate species.

And it is the same problem they have calling three strains of the same weed different species.

This is one of the inconsistencies I speak of. There are many more.

With Coyotes and Dogs you can put the two together and get a Coydog but the two species would not naturally produce a stable population of Coydogs due to the way in which their genes are expressed. Thus they are two separate species.

But mistakes or difficulties in classification shouldn’t and don’t negate the change that is happening. It’s just an issue of what you call the organism.

If you accept that organisms can change, generation on generation, in genetic and structural terms then why is the idea of a mouse like creature eventually producing a dog like creature impossible? It doesn’t matter at what point you call it a new species or genus or whatever.

Originally posted by Mike_A
With Coyotes and Dogs you can put the two together and get a Coydog but the two species would not naturally produce a stable population of Coydogs due to the way in which their genes are expressed. Thus they are two separate species.

I do not agree with this. And by the way, this is the same argument that was long posited in the argument about the wolf and the dog.

If you accept that organisms can change, generation on generation, in genetic and structural terms then why is the idea of a mouse like creature eventually producing a dog like creature impossible? It doesn’t matter at what point you call it a new species or genus or whatever.

I do accept that organism can and are changing from generation to generation, because it is a physical fact. I don't rule out that a mouse to shove out a dog at any point in its life....there just isn't any evidence of it occurring yet. That would be my ultimate point. If you are asking me to accept that it has based on faith, just say so. Because that's all I could really use to accept it in the absence of evidence.

Originally posted by Mike_A
Look at the difference between a Wolf and a Jack Russell for example, extreme differences are clearly observed both directly and indirectly.

That's a bad example. They're both part of the same species, remember? I thought we'd gotten past intraspecies adaptation. I thought we were talking about speciation from one species to a brand new one (without hybridization of very similar and questionably same-species species).

No I was talking about morphology.

Correct me if I’m wrong but your principle objection is that you do not agree that an organism can develop from a morphologically very different organism.

Going back to speciation; if you define it as the point at which two populations are no longer able to interbreed (as is generally the case) then that has been observed both in nature and in the lab. Whether that comes about through hybridization or whatever process is irrelevant. The Goatsbeards was one example, even though it came to be through hybridization the resulting new population was genetically isolated from both parent species; thus speciation had occurred.

But as I said species is a fuzzy concept but it is a categorization problem that you could really throw out and still be left with the concept of evolution intact. If you define everything as one species or as different species it is still observed that organism change dramatically, generation on generation both morphologically and genetically in response to external factors. Even without the categorization of “species” that is still recognizable as evolution.

Perhaps it’s best to think of the “what is a species” problem as something that is post fact; evolution happens but how we categorizes the outcome is difficult. Remember, the theory of evolution explains the process that causes change in a population irrespective of how you categorize that change.

Originally posted by Mike_A

Perhaps it’s best to think of the “what is a species” problem as something that is post fact; evolution happens but how we categorizes the outcome is difficult. Remember, the theory of evolution explains the process that causes change in a population irrespective of how you categorize that change.

We're back to our point of agreement then. Now, if you come back and ask me if I think a mouse could evolve to the point it creates a dog (no matter how many iterations of intraspecies mutations it would take), I would have to repeat that when it happens I'll say - I'll be damned. Until then, I hold it as a dubious thought experiment.

You can talk about odds if you like.

Let's call the intended output the "mog". Let's say the mouse continues to evolve intraspecies until it pops out a whole new species called the "mog".

How are you defining species in this instance?

We’ve already agreed that organisms can change genetically and morphologically to an extreme degree what else does evolution say should happen?