Evolution: the Facts.

[randman]

Ah, no, I see what the issue is. You are confusing speciation with evolution. Speciation is something that evolution leads to, not what evolution is.

Ah, come on. I am not talking about definitions of words but the process. You can define "evolution" any way you want. So what? The issue is the origin of higher taxa.

Evos say that happens through speciation, right?

That more and more speciation adds up to new, higher taxa. That process though involves subgroup isolation, usually envisioned as geographic isolation prior to mutations though there are alternative means of isolation. That's basic evolution 101, which is why you asking for "citations" is inexplicable to me if you are understand evolutionary theory.

Don't mean to get so upset but I shouldn't have to take the time to explain what your side advocates!

So this process of isolation means the group splits off, hence less access to genes over time. You kind of alluded and admitted to recognizing this in an earlier post. Genetic variability decreases.

Now, why is genetic variability important?

For a population of individuals to succeed over evolutionary time, it must contain genetic variability.....

The cheetah is a species that suffers from low genetic variability. Because of hunting and the narrowing of its habitat, fewer and fewer cheetahs are found. Those that are found are often related. A population of closely related individuals exhibits low variability. This is especially critical (and dangerous) if the environmental conditions change and the population does not have the variability to cope with the change. That population could rapidly move toward extinction.

http://www.ndsu.edu/pubweb/~mcclean/plsc431/popgen/popgen1.htm

Microevolution helps explain extinction and can be used to posit speciation but it's not a good mechanism or explanation for the origin of higher taxa. It's evolution in the wrong direction genetically.

 

[Nonpareil]

Deleted. Weird stuff goin' on in this thread.

 

[randman]

Hey, wow! You took a concept that NO ONE BELIEVES CAN HAPPEN and have shown that no one believes it can happen! Therefore, magic.

Yea, I just quoted one of the seminal originators of population genetics and acknowledged by all knowledgeable evos as one of them and someone greatly admired and respected, that laid down a good portion of the theory you believe today (the Modern Synthesis), but you in your ignorance had never heard of him and say to me, hey, that sounds like magical thinking.

Indeed.

 

[Wowbagger]

Hardy, Weinberge and population geneticists are the ones saying this.

I can summarize why they are not with only a few sentences:

They are NOT saying "The primary way evolution is envisioned to occur is that small groups are isolated and evolve."

They ARE saying something like this: "Evolution will NOT (likely) occur if the population is TOO large, or there is TOO much migration in and out of the population".

The difference is subtle, but very important. I hope you see why.

 

[Nonpareil]

Ah, come on. I am not talking about definitions of words but the process.

How you define it is irrelevant. You have mixed up a reference to speciation with evolution, and because other people do define them correctly, you perceived an inconsistency.

If you want to define "evolution" differently, go right ahead, but don't try to swap your definition for anyone else's.

You can define "evolution" any way you want. So what? The issue is the origin of higher taxa.

Evos say that happens through speciation, right?

I'm not a biologist, but as far as I am aware, yes.

That more and more speciation adds up to new, higher taxa. That process though involves subgroup isolation, usually envisioned as geographic isolation prior to mutations though there are alternative means of isolation. That's basic evolution 101, which is why you asking for "citations" is inexplicable to me if you are understand evolutionary theory.

I didn't ask for citations.

Don't mean to get so upset but I shouldn't have to take the time to explain what your side advocates!

I know what "my side" advocates, thank you very much. But what you are complaining that I do not understand has nothing to do with the objections I raised in my previous post. I was pointing out where you had mixed up speciation with evolution, and this was where your reasoning had gone awry.

If you disagree, explain why, but don't try to change the subject like this. If you want to understand evolution, you need to be willing to admit that you don't know it all already.

You kind of alluded and admitted to recognizing this in an earlier post.

I haven't posted here before. Not in response to you, anyway.

Now, do you understand why differentiating between evolution and speciation is important? Do you understand why the "infinitely" descriptor is important?

 

[sphenisc]

They ARE saying something like this: "Evolution will NOT (likely) occur if the population is TOO large, or there is TOO much migration in and out of the population".

No it's an absolute statement about infinite populations, not a probabilistic one about large ones.

If, in an infinite population, one particular allele has a frequency of 2, and in the next generation it has a frequency of 3 then the change in relative frequency goes from 2/inf -> 3/inf which is 0 -> 0, which is no change in relative frequency. This would be true for any finite allele frequency in an infinite population, but only in an infinite population.

 

[Dinwar]

Yea, I just quoted one of the seminal originators of population genetics and acknowledged by all knowledgeable evos as one of them and someone greatly admired and respected, that laid down a good portion of the theory you believe today (the Modern Synthesis), but you in your ignorance had never heard of him and say to me, hey, that sounds like magical thinking.

I'm familiar with HWE. I know what it does and does not say. It does NOT say " There has to be some migration (subgrouping; there cannot be mating across the whole population, etc,....I don't really like the word "random" there but what they are getting at is there must be either geographic or sexual isolation of a subgroup for evolution to occur. Otherwise, the mutation would be washed out in the larger population." They say that if a population fits X parameters it will not evolve; if not, it will. You are adding your own biases to this interpretation (the reason you think that the bolded parts are what they're getting at is your a priori assumptions, not what HWE states). If you'd read the books I referenced you'd know this as well.

That process though involves subgroup isolation, usually envisioned as geographic isolation prior to mutations though there are alternative means of isolation.

This only works for animals. Other taxa work differently. And not for all animals either. I'll give you a pass on this bias, though--it's fairly common.

 

[Dancing David]

So let us see what we have, and I will address the articles and the arguments made earlier,

Your response to a question was :

Hardy, Weinberge and population geneticists are the ones saying this.

Hardy, Weinberg, and the population geneticists who followed them came to understand that evolution will not occur in a population if seven conditions are met:

1. mutation is not occurring
2. natural selection is not occurring
3. the population is infinitely large
4. all members of the population breed
5. all mating is totally random
6. everyone produces the same number of offspring
7. there is no migration in or out of the population

http://anthro.palomar.edu/synthetic/synth_2.htm

But what was the question?

The primary way evolution is envisioned to occur is that small groups are isolated and evolve.

Nope, try again, who said that where?

So the question was who said that the primary way for evolution to occur is that small groups are isolated?

So I look at your response, and I don't see that answered, now I admit I can be very dense, so please parse out for me how the part you quoted says that "The primary way evolution is envisioned to occur is that small groups are isolated and evolve.
"

because I don't see that happening, in the quote you gave.

 

[Dancing David]

So can you see where the concept of isolation is critical to the whole foundation of NeoDarwinism since evolution is considered to advance through speciation?

It's really a simple but sometimes overlooked point.

No I looked at your material really it doesn't, there are a number of factors, evolution is the process of change in members of a breeding population through reproductive success. It can be that some memebers are isolated, it can be that some are not, take the trait of sickle cell anemia, it developed in response to teh malarial papasite in a large non-homogeous population in Africa. It spread because of the malaria parasite and the reproductive success of people with half a trait, not because of isolation.

So isolation is not needed, reproductive success is, but please continue to make your case, I am trying to understand.

 

[Dinwar]

So can you see where the concept of isolation is critical to the whole foundation of NeoDarwinism since evolution is considered to advance through speciation?

Again, this is only within animals (and even there it's a misconception). Within plants this is not the case. Bacteria clearly play by different rules. We'll leave Protists out; in my opinion it should be subdivided into multiple kingdoms.

Also, evolution doesn't "advance through speciation". First off, good luck defining "species". Better scientists and philosophers than anyone here have tried and failed. Secondly, a species can evolve without speciation. Look at humans--the entire species started off as dark-skined, but I'm so white I wash out photographs if my shirt's off (an embarising revelation from an ex-girlfriend). Yet I could easily mate with a dark-skinned woman and have viable offspring. Or, look at circle species (which REALLY throws the whole species concept into disaray, as well as showing that evolution clearly can happen even within interbreeding populations).

 

[randman]

Do you see it in this quote?

Speciation involves the genetic change in a subgroup of a population that renders the new population incapable of reproducing offspring with the original population. If a reproductive barrier occurs because of isolation by a physical barrier, the isolated population can evolve and develop into a new species. This process is termed allopatric speciation. This has been considered for a long time to be the primary mode of speciation.

Speciation can also occur when a subpopulation migrates into a new niche. This is termed parapatric speciation, and this process seems to have been used by some annual plants.

The final form of speciation is called sympatric speciation. This type of speciation occurs when a subpopulation that occupies the same niche as the remainder of the species develops a unique mutation that prevents it from mating with the original population.

http://www.ndsu.edu/pubweb/~mcclean/plsc431/popgen/popgen6.htm

So can you see where the concept of isolation is critical to the whole foundation of NeoDarwinism since evolution is considered to advance through speciation?

It's really a simple but sometimes overlooked point.

A note to others, if you actually did not understand evolutionary theory only happens for the origin of higher taxa, you really ought not to think or claim you have a basic understanding of evo theory and should just ask some questions to get a better handle on this or do some reading before you set about to argue.

 

[Nonpareil]

<snip copypasta>

So you're just going to copy and paste previous posts rather than actually respond to what people have said to you?

 

[Dinwar]

Do you see it in this quote?

Yes, and I explained how it's based on a faulty premise. You assume 1) that speciation drives evolution, and 2) that allopatric speciation is the only type. 1 is clearly false, as has been explained many times with specific examples (for my part, humans and circle species), and 2 is shown to be wrong by the mere fact that we have the qualifier "allopatric" in front of it. Ever hear of hybred plants? That's speciation which is NOT allopatric.

So, again, you're wrong. You can continue to call it a simple and frequently missed point if you wish, but it's still wrong.

Besides, you're using the biological species concept. What about the morphospecies concept (no issolation necessary)? Or any of the other species concepts involved? The term "species" is not a clearly defined term, and thus neither is "speciation".

A note to others, if you actually did not understand evolutionary theory only happens for the origin of higher taxa, you really ought not to think or claim you have a basic understanding of evo theory and should just ask some questions to get a better handle on this or do some reading before you set about to argue.

That's rich, coming from a guy who STILL refuses to read the booksk I referenced. Why is that, I wonder.......

 

[randman]

Again, this is only within animals (and even there it's a misconception). Within plants this is not the case.

And the point was made in reference to sexually reproducing creatures to avoid something like your post above, which could be debated.

Also, evolution doesn't "advance through speciation"

The origin of higher taxa does according to the theory you are supposed to be familiar with commonly referred to "evolution" and I call Darwinism or Neodarwinism.

First off, good luck defining "species".

Interesting isn't it that a basic scientific definition among evos is so difficult. Maybe there is a reason for that?

Better scientists and philosophers than anyone here have tried and failed.
Secondly, a species can evolve without speciation.

Depends on how define evolve. They change back and forth within a range; hence stasis being such a dominant feature in living biota and the fossil record despite "evolution" as mere heritable change happens all the time.

Yet I could easily mate with a dark-skinned woman and have viable offspring.

I don't think that counts as "evolution" per se.

 

[randman]

as has been explained many times with specific examples (for my part, humans

I know. Your explanation of mating with a dark-skinned women being your example.

Forgive me if I don't read all of your posts, not because of the idea of mating with a dark-skinned woman but of thinking that in any way at all is "evolution" as we are discussing it.

If you have some books you'd suggest, feel free to repost them.

 

[randman]

So you're just going to copy and paste previous posts rather than actually respond to what people have said to you?

If one cannot understand why isolation of a population is necessary for evolution of the higher taxa via multiple sequential speciation events, nothing else is going to make sense. It's really no use discussing evolution until they at least have that basic concept down pat, and it's a very, very simple one.

 

[randman]

No I looked at your material really it doesn't, there are a number of factors, evolution is the process of change in members of a breeding population through reproductive success. It can be that some memebers are isolated, it can be that some are not, take the trait of sickle cell anemia, it developed in response to teh malarial papasite in a large non-homogeous population in Africa. It spread because of the malaria parasite and the reproductive success of people with half a trait, not because of isolation.

So isolation is not needed, reproductive success is, but please continue to make your case, I am trying to understand.

Just think about it. Explain to me how the higher taxa can evolve without sequential speciation.

We cannot mate with, say, a frog, right? We are sexually isolated.

 

[Nonpareil]

If one cannot understand why isolation of a population is necessary for evolution of the higher taxa via multiple sequential speciation events, nothing else is going to make sense. It's really no use discussing evolution until they at least have that basic concept down pat, and it's a very, very simple one.

So you haven't even been reading the replies, then.

I can see already that this is going nowhere. Bye-bye.

 

[Wowbagger]

No it's an absolute statement about infinite populations, not a probabilistic one about large ones.

I suppose it's not a useful statement to pick on, is it then.

 

[sphenisc]

I suppose it's not a useful statement to pick on, is it then.

I think so, it was the relevant one to address your point.