Microscopes and telescopes

[johnhanks]

*edit* In recent years at least creationists have been forced to admit, however reluctantly, that what they call "microevolution" is a reality; it is at the level of "macroevolution" that they dig in their heels, demanding (like the poster above) to be shown the process happening before they'll accept it as possible.

When it comes to observing evolution, we have two very different scales on which we can see it happening. "Microevolution" we can document meticulously within the timescale of human careers, and can record changes in populations up to and including the level of speciation.

Just as a microscope is an excellent tool for looking at cells, but useless for observing galaxies, direct population monitoring during a human lifespan is never going to record "macroevolution", the emergence of higher level taxa. For that we need the "telescope" of palaeontology, which allows us to observe tens of millions of years' worth of events in a few metres of rock strata. There we see macroevolution writ plain in transitions such as lobe-finned fish to Amphibia, Cetartiodactyla to whales and even-toed ungulates, and the whole adaptive radiation of mammals. However, the relatively coarse resolution of the fossil record means it rarely reveals microevolution: palaeontologists, honest folk that they are, candidly admit that transitional fossils are rare at species level, giving creationists (less honest folk) wonderful opportunities for quote-mining.

In short, we have two excellent instruments for observing evolution, but only a fool would complain that each was useless for the other's purpose. Our creationist poster quoted at the top is the equivalent of someone refusing to admit galaxies exist until we show him one in an electron microscope; those who jump on the fossil record's poor showing as a record of microevolution are in effect refusing to believe in mitochondria until the Hubble Space Telescope takes a picture of one.

Are any of our resident creationists prepared to argue this one out?

 

[secret2]

I am still waiting for someone to propose a mechanism to halt macroevolution while permitting microevolution (where the heck is the line, anyway?)

My best guess is that creationists expect to observe human popping out of monkey vagina before they would acknowledge "macroevolution".

 

[Copernicus]

I am still waiting for someone to propose a mechanism to halt macroevolution while permitting microevolution (where the heck is the line, anyway?)

My best guess is that creationists expect to observe human popping out of monkey vagina before they would acknowledge "macroevolution".

I think that they draw the "species" line at one very specific place--the ability to produce offspring. So donkeys and horses have to be of the same "species" from their perspective, even though mules cannot themselves produce offspring. If you bring up the subject of a "ring species", they'll argue that the ends of the ring can mate, in principle, but they choose not to.

You ask a very good question. What, in principle, prevents macro evolution, as they define it, from taking place? The answer is as simple as can be: God. God won't let it happen. An evolutionary theist believes that God lets it happen, makes it happen, or fails to stop it from happening. If you believe in miracles--god-driven magic--then it isn't hard to cling to dogmatic beliefs. You always have a simple, ready answer.

 

[johnhanks]

I am still waiting for someone to propose a mechanism to halt macroevolution while permitting microevolution (where the heck is the line, anyway?)

As I've suggested elsewhere, the crucial difference is that people who understand evolution know it's quantitative change (in the distribution of ATCG nucleotides in a population's genome) whilst creationists demand that it be qualitative change (from one "kind"* to another) and thus (they claim) impossible.

My best guess is that creationists expect to observe human popping out of monkey vagina before they would acknowledge "macroevolution".

Ouch. Poor monkey.



*whatever the hell a "kind" is.

 

[ruffen]

Evolution of species is a lot like evolution of languages. For each generation, people have different slang words and speak slightly different from their parents. Give it enough generations, and you have different dialects (microevolution), and give it more generations, you get different languages (macroevolution).

Just like species, languages are classed into families and some are more closely related than others. Different languages have evolved over the millennia, but at no point did a French mother give birth to a Spanish-talking kid and they didn't understand each other. It is a very gradual process, and at no point can you say "THERE is the point where the language switched over from one to another".

And none of the modern-day languages evolved from other modern-day languages, they evolved from a common language that was neither French, nor Spanish, in the same way humans didn't evolve from modern day chimps, but we, chimps and bonobos have a common ancient ancestor.

And the thing most evolution-skeptics underestimate grandly is the vast amounts of time that has passed. Just imagining thousands and millions of years passing is difficult.

But of course if you believe in the Babel-tower-hypothesis to explain why there are different languages in the world, you're still stuck in understanding evolution.

 

[Alceste]

As I've suggested elsewhere, the crucial difference is that people who understand evolution know it's quantitative change (in the distribution of ATCG nucleotides in a population's genome) whilst creationists demand that it be qualitative change (from one "kind"* to another) and thus (they claim) impossible.
Ouch. Poor monkey.



*whatever the hell a "kind" is.

A "kind" is whatever it needs to be in order to convince yourself two of everything on earth could be crammed onto a boat.

 

[Copernicus]

Evolution of species is a lot like evolution of languages. For each generation, people have different slang words and speak slightly different from their parents. Give it enough generations, and you have different dialects (microevolution), and give it more generations, you get different languages (macroevolution).

As a linguist, I can think of a number of ways in which this analogy fails, but I understand the point you are trying to make with it.

Just like species, languages are classed into families and some are more closely related than others. Different languages have evolved over the millennia, but at no point did a French mother give birth to a Spanish-talking kid and they didn't understand each other. It is a very gradual process, and at no point can you say "THERE is the point where the language switched over from one to another".

Dialect and language boundaries tend to result from the physical (and social) separation of speech communities. It could also be said that biological evolution tends to result from the environmental separation of populations. I wouldn't belabor the point too much, because languages don't really change in terms of complexity over time, as far as we know. All languages (with the possible exception of pidgins and creoles) tend to be equally complex. In biology, it seems that complexity has been on the increase over time, although there can be exceptions to the generalization.

 

[Alceste]

As a linguist, I can think of a number of ways in which this analogy fails, but I understand the point you are trying to make with it.

Dialect and language boundaries tend to result from the physical (and social) separation of speech communities. It could also be said that biological evolution tends to result from the environmental separation of populations. I wouldn't belabor the point too much, because languages don't really change in terms of complexity over time, as far as we know. All languages (with the possible exception of pidgins and creoles) tend to be equally complex. In biology, it seems that complexity has been on the increase over time, although there can be exceptions to the generalization.

That's a little problematic. How do you define "complexity"?

 

[rusra02]

This cri de coeur, extracted from a thread in the Science and Religion section, reflects a common creationist manoeuvre. In recent years at least creationists have been forced to admit, however reluctantly, that what they call "microevolution" is a reality; it is at the level of "macroevolution" that they dig in their heels, demanding (like the poster above) to be shown the process happening before they'll accept it as possible.

When it comes to observing evolution, we have two very different scales on which we can see it happening. "Microevolution" we can document meticulously within the timescale of human careers, and can record changes in populations up to and including the level of speciation.

Just as a microscope is an excellent tool for looking at cells, but useless for observing galaxies, direct population monitoring during a human lifespan is never going to record "macroevolution", the emergence of higher level taxa. For that we need the "telescope" of palaeontology, which allows us to observe tens of millions of years' worth of events in a few metres of rock strata. There we see macroevolution writ plain in transitions such as lobe-finned fish to Amphibia, Cetartiodactyla to whales and even-toed ungulates, and the whole adaptive radiation of mammals. However, the relatively coarse resolution of the fossil record means it rarely reveals microevolution: palaeontologists, honest folk that they are, candidly admit that transitional fossils are rare at species level, giving creationists (less honest folk) wonderful opportunities for quote-mining.

In short, we have two excellent instruments for observing evolution, but only a fool would complain that each was useless for the other's purpose. Our creationist poster quoted at the top is the equivalent of someone refusing to admit galaxies exist until we show him one in an electron microscope; those who jump on the fossil record's poor showing as a record of microevolution are in effect refusing to believe in mitochondria until the Hubble Space Telescope takes a picture of one.

Are any of our resident creationists prepared to argue this one out?

Microevolution is a term coined by evolutionists to describe variations that occur within a species. As such, I believe it is misleading, because such variations do not create new kinds of insects, birds, or animals. Fruit flies remain forever fruit flies, for example.
As to the fossil record, evolutionists interpret the evidence to support their presuppositions, I.e. that evolution is the only explanation they are willing to accept. Thus, evidence for rapid creation, as in the so-called "Cambrian Explosion" is ignored or downplayed. You then blame the fossil record, which you rely on for proof, for not providing the proof of transitional links because it is too "course". Meanwhile, you impugn the truthfulness of those who reject evolution whilst calling evolutionists "honest folk". Macroevolution cannot be demonstrated because it never happened, plain and simple.

 

[sonofdad]

What prevents macro-evolution from happening?
Variations in populations are inevitable as long DNA is not copied perfectly between parent and offspring and the environment keeps changing. I'm sure you know this. You really need an intelligent being to prevent the changes from happening rather than the other way around.
But what exactly is the mechanism that prevents the variations from going from micro to macro (macro essentially just being a lot of micro)?

What you're saying is basically the equivalent of saying that a guy with two fully functional legs can take two steps forward but he can't walk 100 meters, which could be true if there's a big electric fence in his path.
Is there a big electric-fence standing in the way of evolution?

 

[johnhanks]

As to the fossil record, evolutionists interpret the evidence to support their presuppositions, I.e. that evolution is the only explanation they are willing to accept. Thus, evidence for rapid creation, as in the so-called "Cambrian Explosion" is ignored or downplayed.

If you study the so-called "Cambrian Explosion" you will find it offers very poor support for creation. Phyla appear over some tens of millions of years, and few of the life-forms represented bear any relation to those we see today: evolution has replaced them. Show us a Cambrian whale (or a teleost or even an insect) and you're on to something.

You then blame the fossil record, which you rely on for proof, for not providing the proof of transitional links because it is too "course".

A typical piece of creationist selective quotation. The fossil record is too coarse to show up transitionals at the species level - but that's no problem, because we can see them around us today. Transitions between higher taxa show up beautifully in the fossil record - like the recent find linking early turtles to non-shelled reptiles.

Meanwhile, you impugn the truthfulness of those who reject evolution ...

Yes, a shameful calumny. After all, it's not as if a creationist would ever write "You ... blame the fossil record ... for not providing the proof of transitional links because it is too "course" [sic]" when the person they're quoting was referring only to transitional links at species level, and had celebrated their abundance elsewhere. Is it?

...
whilst calling evolutionists "honest folk". Macroevolution cannot be demonstrated because it never happened, plain and simple.

The fossil record shows that it has; and we are still waiting for your explanation of the mechanism that prevents small generation-to-generation changes in gene pools from accumulating to changes in "kind". Come to that, we are still waiting for you and your fellow creationists to tell us what a "kind" is.

 

[ScottySatan]

We have the technology to observe macroevolution, but no one's doing it...yet.

Researchers at Princeton are keeping baker's yeast alive continuously in a large fermentor. They occasionally take a sample out and sequence the entire genome, making note of any changes. So far they've only done it to map in real time the microevolutionary response to stress. But, if they kept the culture going for years (one generation = 2 hours) or even decades, taking genome sequence samples periodically, I think you would see macroevolution. Maybe a big E. coli tank would be better (one generaton = 20 minutes).

Unfortunately, it wouldn't satisfy creationists because the strange new cell would probably still look the same as the starting organism to an untrained eye.

 

[johnhanks]

Unfortunately, it wouldn't satisfy creationists because the strange new cell would probably still look the same as the starting organism to an untrained eye.

Absolutely. Genetically, Archaea have more in common with us than with the Eubacteria, but to the creationist they're all just "microbe kind".

 

[ScottySatan]

But what exactly is the mechanism that prevents the variations from going from micro to macro (macro essentially just being a lot of micro)?

time. that's all.

edited to add:

I forgot to mention that evolution is not just about the accumulation of random mutations that are rarely beneficial. There are at least a dozen other methods of heritable genetic change that are much much faster than that. So the answer of "time" is not the cop-out that some might think.

 

[Ouroboros]

We have the technology to observe macroevolution, but no one's doing it...yet.

Researchers at Princeton are keeping baker's yeast alive continuously in a large fermentor. They occasionally take a sample out and sequence the entire genome, making note of any changes. So far they've only done it to map in real time the microevolutionary response to stress. But, if they kept the culture going for years (one generation = 2 hours) or even decades, taking genome sequence samples periodically, I think you would see macroevolution. Maybe a big E. coli tank would be better (one generaton = 20 minutes).

The E.Coli has been done, and I think is still going on. E. coli long-term evolution experiment - Wikipedia, the free encyclopedia
They discovered new strains that evolved an "irreducible complex" ability to use citric acid (if I remember right) for food.

There's been similar experiments with bacteria evolving resistance against antibiotics.

Unfortunately, it wouldn't satisfy creationists because the strange new cell would probably still look the same as the starting organism to an untrained eye.

Except for the genetic code would look different, and that has been confirmed. The difference in the expression of genes can be documented now using DNA sequencers. It's gone to the point where synonymous codons are used to trace heritage between individuals, and also to realize that we are related to the apes. The phylogenic tree can be established using several methods of gene comparisons. Evolution is not a guess based on look-a-like anymore, but established facts based on real codes in the DNA. I'd say arguing the truth of evolution is a moot point. There's nothing more to say than to just accept reality. Here's one thing I thought of the other day, evolution is the most controversial science in our history. It's been protested against and held back and fought at every turn, yet the evidence keeps on coming in to support it. Scientists have worked really hard to test evolution to confirm if it's true or not, and it constantly proves itself to be true. Evolution fits the evidence. Creationism doesn't. This doesn't mean that there's a possibility of a God behind the scenes using evolution to create life. That's still an open question.

 

[Falvlun]

I am still waiting for someone to propose a mechanism to halt macroevolution while permitting microevolution (where the heck is the line, anyway?)

There's a point at which a gene just refuses to mutate, of course. "No sir, I can't mutate again, because if I do, that will make it macroevolution."

 

[Ouroboros]

There's a point at which a gene just refuses to mutate, of course. "No sir, I can't mutate again, because if I do, that will make it macroevolution."

It's an anti= macro evolution gene,

 

[Copernicus]

There's a point at which a gene just refuses to mutate, of course. "No sir, I can't mutate again, because if I do, that will make it macroevolution."

That's the point where the gene becomes too big for its britches.

 

[sonofdad]

It's an anti= macro evolution gene,

Is that an irreducibly complex gene?

 

[Ouroboros]

Is that an irreducibly complex gene?

Yes. Or perhaps an anti-reducible complex? It's the God-gene, I bet.