Why Is Only "Micro Evolution" Acceptable?

[hitch1978]

Just to get some clarification.

So a species has within it's species genepool/DNApool (I don't know which one 'works' so I will refer to it/them as a species' 'pool' from here on in.) the range a,b,c,d,e,f and g. But the predominant features within the species are all in the d range.

Something happens that makes the e range predominant. But the overall range does not shift. Correct?

Is there also the assumptiun that h can ever develope as part of the pool? Or z? (as a wraparound gene straight.)

I have struggled with a suitable analogy, and my wording. Sorry.

I think that if you accept micro but not macro, you have to agree with my points above. Does that sound right?

[madnak]

Most organisms have a large number of genes in their chromosomes that are not ordinarily expressed. Many phenotypic ("observable") changes can be the result of which genes are expressed and how they're expressed, rather than which genes actually exist in the DNA.

However, it's pretty much established that mutations sometimes occur - when the DNA is being replicated, "errors" happen that result in new genes altogether. The new genes then create new proteins that didn't exist in the parent(s). Thus, traits "h" and "z" can appear.

The main argument of the educated "micro but not macro" crowd is simple. They say that in order for a new useful function to appear, traits "h," "j," and "p" all have to be present. The idea is that any one of these traits is bad, but all of them combined is good. Therefore, in order for them to evolve they all have to appear at the same time. And the likelihood of that happening is extremely low.

[vhawk01]

[ QUOTE ]
Just to get some clarification.

So a species has within it's species genepool/DNApool (I don't know which one 'works' so I will refer to it/them as a species' 'pool' from here on in.) the range a,b,c,d,e,f and g. But the predominant features within the species are all in the d range.

Something happens that makes the e range predominant. But the overall range does not shift. Correct?

Is there also the assumptiun that h can ever develope as part of the pool? Or z? (as a wraparound gene straight.)

I have struggled with a suitable analogy, and my wording. Sorry.

I think that if you accept micro but not macro, you have to agree with my points above. Does that sound right?

[/ QUOTE ]

This is not what actually happens, this is his representation of the farce that evolution-deniers are trying to suggest.

[vhawk01]

[ QUOTE ]
Most organisms have a large number of genes in their chromosomes that are not ordinarily expressed. Many phenotypic ("observable") changes can be the result of which genes are expressed and how they're expressed, rather than which genes actually exist in the DNA.

However, it's pretty much established that mutations sometimes occur - when the DNA is being replicated, "errors" happen that result in new genes altogether. The new genes then create new proteins that didn't exist in the parent(s). Thus, traits "h" and "z" can appear.

The main argument of the educated "micro but not macro" crowd is simple. They say that in order for a new useful function to appear, traits "h," "j," and "p" all have to be present. The idea is that any one of these traits is bad, but all of them combined is good. Therefore, in order for them to evolve they all have to appear at the same time. And the likelihood of that happening is extremely low.

[/ QUOTE ]

And chromosomes double, leading to a whole new batch of useless (and therefore free to 'experiment' on) base pairs. And chromosomes halve, and translocate, and invert.

And there are insertion mutations too, not just deletion mutations.

[hitch1978]

[ QUOTE ]
[ QUOTE ]
Just to get some clarification.

So a species has within it's species genepool/DNApool (I don't know which one 'works' so I will refer to it/them as a species' 'pool' from here on in.) the range a,b,c,d,e,f and g. But the predominant features within the species are all in the d range.

Something happens that makes the e range predominant. But the overall range does not shift. Correct?

Is there also the assumptiun that h can ever develope as part of the pool? Or z? (as a wraparound gene straight.)

I have struggled with a suitable analogy, and my wording. Sorry.

I think that if you accept micro but not macro, you have to agree with my points above . Does that sound right?

[/ QUOTE ]

This is not what actually happens, this is his representation of the farce that evolution-deniers are trying to suggest.

[/ QUOTE ]

That's what I was saying/asking for comfirmation on.

[hitch1978]

How do you define a change in species? Or macroevolution?

Where does Micro end, and Macro begin?

[vhawk01]

[ QUOTE ]
How do you define a change in species? Or macroevolution?

Where does Micro end, and Macro begin?

[/ QUOTE ]

Haha, well, thats a really awesome question, and one of my pet peeves/favorite topics, but I'll assume you are interested in the short version. There is no mechanistic or fundamental difference between microevolution and macroevolution. I get in trouble for saying that there is no such thing as micro/macro, because its not TECHNICALLY true, but it is probably more accurate than the divide that the terminology implies to most people.

Basically, speciation is the boundary. Speciation is generally (though not always) defined as the point in the phenotypic divergence of two populations where members of group A can no longer procreate with members of group B. So, speciation could be any number of events. Say you have two groups that are identical, but they separate for some reason. Originally, these animals mate during the morning, ONLY during the morning. For some reason, the animals in group B, over time, start to mate later and later in the day, to the point where now they only mate in the evening. Assume that NO OTHER CHANGES have taken place. They look identical to one another, still. Now, you bring these populations back into contact. They all live together in one big group. But group A animals cannot mate with group B animals. They are two entirely different species. We've just witnessed macroevolution. For all intents and purposes, these two groups will now continue to diverge for eternity, since there will be no mingling of genes between the groups.

The cute part is, these animals in group B could now, over time, go back to mating in the morning, and as long as there weren't any major changes to their physiology or physical make-up, they could ONCE AGAIN become the same species. I'm not sure if this has ever happened (and I think I would have read about it if it ever had) but it is at least theoretically possible. Let the macro-deniers chew on that one.

EDIT: And yes, that was the short version. If you have more questions I'll do my best, and Rduke can probably be summoned to answer anything I can't. Madnak, Phil and several others are also pretty well-versed.

[hitch1978]

Thankyou. I have lots more.

I am kind of stumbling through a subject that many of you seem well versed on, and I thank you for your patience.

Please correct whichever of the following statements is false.

OK,

1) The definition of 'species' is groups of animals that can mate. So, as an easy axample, defferent breeds of domestic dog are the same species.

2) The accepted meaning of 'microevolution' is where a change in an animal's genetic makeup is made, but where that change does not affect what species said animal can mate with.

3) The accepted meaning of 'macroevolution' is where a change in an animal's genetic makeup is made, but where that change does affect what species said animal can mate with.

4) If an entire species modifies it's gentiec makeup, there are no boundries as to how far it can go within the confines of microevolution, as the definition allows us to say it has not undergone macroevolution.

5) We are capable of gentiically modifying some animals to reduce pests. (Again, I am not particularly well versed on the subject. I will state my case as fact (As I believe it is) and allow others to correct.) In the case of some insects we can make it so we can introduce GM'd parents that produce offspring that cannot reproduce, thus driving down the numbers of a species. Have these offspring have gone through macroevolution as they can no longer mate with the same species.

Like I said, I am just stabbing around, looking for answers.

I took mate to mean reproduce.

[Matt R.]

2 and 3 are wrong, and I think 4 is by extension.

Microevolution is simply change in allele frequencies within a population. Alleles are the different versions of a given gene. Macroevolution typically deals with larger scale evolutionary phenomena. An example given on wiki is how feathers appeared from birds when they diverged from one group of dinosaurs.

Speciation isn't really a micro/macroevolution question. It occurs on both levels, depending on how you look at it. It is of course related to changes in allele frequencies, as these changes alter the reproductive capabilities of the animals. And it's related to macro as well b/c you're looking beyond a single simple population.

I'm not sure I understand #5. What does "GM'd parents" mean? If you're wondering if the offspring are "separate species", the answer is no because they cannot interbreed at all.

[vhawk01]

[ QUOTE ]
Thankyou. I have lots more.

I am kind of stumbling through a subject that many of you seem well versed on, and I thank you for your patience.

Please correct whichever of the following statements is false.

OK,

1) The definition of 'species' is groups of animals that can mate. So, as an easy axample, defferent breeds of domestic dog are the same species.

2) The accepted meaning of 'microevolution' is where a change in an animal's genetic makeup is made, but where that change does not affect what species said animal can mate with.

3) The accepted meaning of 'macroevolution' is where a change in an animal's genetic makeup is made, but where that change does affect what species said animal can mate with.

4) If an entire species modifies it's gentiec makeup, there are no boundries as to how far it can go within the confines of microevolution, as the definition allows us to say it has not undergone macroevolution.

5) We are capable of gentiically modifying some animals to reduce pests. (Again, I am not particularly well versed on the subject. I will state my case as fact (As I believe it is) and allow others to correct.) In the case of some insects we can make it so we can introduce GM'd parents that produce offspring that cannot reproduce, thus driving down the numbers of a species. Have these offspring have gone through macroevolution as they can no longer mate with the same species.

Like I said, I am just stabbing around, looking for answers.

I took mate to mean reproduce.

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If I said mate, I should have been more careful, reproduce is the correct term. For the most part that all seems fine. Its hard to say EXACTLY what is meant when people say microevolution and macroevolution since, for the most part, whenever you hear those two terms, the person using them is being intentionally dishonest and trying his best to obfuscate. As far as there is a scientifically accepted definition of those terms, however, you've pretty well nailed it.

You do hint at another interesting point in that micro and macro don't REALLY have anything to do with the extent of the changes. Micro evolution could result in modern humans being three times the size or having twice as many limbs or something crazy as ancient humans, but they could still be the same species. It also hints at the true problem with the species designation: species are convenient for animals that are seperated spatially or geographically. The absurdity of the definition comes when we consider that all animals are separated TEMPORALLY as well. If human beings continue to thrive for the next 2 million years, its entirely possible that Vhawk the 200,000th or whatever could not reproduce with someone today. But it would be very difficult to know for sure, and there would be a seamless, unbroken string of people between me and him, all of whom could mate with all other contemporary humans. Under these conditions, the term "species" seems ludicrous, doesn't it? He can't mate and reproduce with Jessica Alba, he might look entirely different than I do (thus his having no shot at Alba, LDO) but there would never be a point where he would not be considered human.

All organisms are actually like that, we just have the good fortune of all the links in the chain being dead and gone, and no fossils existing. If we had fossils for every individual of every species that ever lived, we probably would have to entirely scrap the concept of species. It would be self-evidently absurd. But that isn't the case, and the term obviously does have some usefulness. Just be very aware of the limitations and artificial nature of "species" whenever you have a discussion with some creationists. It is a crucial sticking point.