Has evolution occured?

[Sanoy]

A while ago Decstar made a poll on whether Christians believe evolution occurs. I initially answered yes, because the process seems rational. But I realized I am not justified, perhaps from ignorance, in saying that it has occurred. So that is what I want to ask the audience. It's not a challenge, so please avoid the usual pretentious remarks. It is just a question. Please avoid pretentious remarks and rhetoric to each other as well.

I want to use the same definition decstar used because I think it's good. It is the definition we will be using for this question because my concern is over mutations and my answer to his question.
** Convenient definition of evolution for those unsure: Evolution is changes in a life form due to mutations in their genetic code, leading to the success or failure (or neither) of the mutation, leading to the mutated creature having more success mating, therefore passing on the improved gene or no success, leading to the gene not being passed on. Or to put it simply, changes in a life form over time. **

So the question is, are there real examples where a life form has acquired a new feature, via mutation, that is broadly advantageous and has been selected? Here is what I mean by broadly. Sickle cell anemia may be an advantage against Malaria, but it's not a broad advantage because it is overall a health problem.

Thanks in advance. And please give a statement about your example works, not just a link. A good description should cover these points. 1)How we know this is a mutation providing something new. 2) how this mutation provides a broad advantage. (IE It is not coupled with significant disadvantages)

 

[Brightmoon]

Sickle cell anemia actually is a mixed trait because those who have it survive malaria which overwhelmingly kills children . That’s an advantage
Here’s Timema cristinae which is in the process of slow speciation.( macroevolution) The 2 morphs are already showing mate preference ( green to green , striped to striped) because they’re background mimics . The intermediates tend to get eaten They look like the plants they eat. And the morphs eat and prefer different plants. The scientific community considers speciation to be macroevolution. The creationists falsely define macroevolution in a way to hide the fact that this is evolution.

This is what evolution actually looks like . pigs don’t turn into cats for example

 

[tas8831]

I want to use the same definition decstar used because I think it's good.
** Convenient definition of evolution for those unsure: Evolution is changes in a life form due to mutations in their genetic code, leading to the success or failure (or neither) of the mutation, leading to the mutated creature having more success mating, therefore passing on the improved gene or no success, leading to the gene not being passed on. Or to put it simply, changes in a life form over time. **

Hate to breach your requested decorum, but that is not a very good definition of evolution. The current basic definition is 'changes in allele frequencies in a population over time.'

So the question is, are there real examples where a life form has acquired a new feature, via mutation, that is broadly advantageous and has been selected? Here is what I mean by broadly. Sickle cell anemia may be an advantage against Malaria, but it's not a broad advantage because it is overall a health problem.

Thanks in advance.

Generally, evolution does not really deal in "new" features, but modifications of already-existing ones. Look at a human, and then look at, say, a cat. What features does a cat have that a human does not - claws? Nails are flattened out claws - some primates still have a claw on each hand. Fur? We have 'fur' - it is just more sparsely and unequally distributed.
Surely, our brains are new! Nope - cat brains are smaller proportionally, and have a less well developed forebrain than we do, but the basic parts? All there.
Etc.


So, to your question, let's go with a more developed forebrain. There is a bit of research on the underlying genetics for this increase in brain size/body mass ratio, and that has allowed us to engage in higher-level cognition, which is the root our our technology.

 

[USincognito]

I can think of plenty of examples of mutations.
- Hoxd12 and Hoxd13 and whale flipper evolution.
- Bmp2, fgf8, etc. and bat wing evolution.
- Sonic Hedgehog/Hand2 pathway and whale hind limb loss.
- SRGAP2C and ARHGAP11B in human brain evolution
- LCT/MCM6 regulation and human lactase production into adulthood.
- CCR5delta32 and HIV immunity
- EPAS1 in Tibetans allowing them to functiin better at altitude.

 

[Sanoy]

Hate to breach your requested decorum, but that is not a very good definition of evolution. The current basic definition is 'changes in allele frequencies in a population over time.'


Generally, evolution does not really deal in "new" features, but modifications of already-existing ones. Look at a human, and then look at, say, a cat. What features does a cat have that a human does not - claws? Nails are flattened out claws - some primates still have a claw on each hand. Fur? We have 'fur' - it is just more sparsely and unequally distributed.
Surely, our brains are new! Nope - cat brains are smaller proportionally, and have a less well developed forebrain than we do, but the basic parts? All there.
Etc.


So, to your question, let's go with a more developed forebrain. There is a bit of research on the underlying genetics for this increase in brain size/body mass ratio, and that has allowed us to engage in higher-level cognition, which is the root our our technology.

I'm sure you are right about the general definition of evolution, but I still want this one because it correlates well with the inquiry.

The problem with forebrains is that we already have them. The answer to this question would have to be something recent. To know that it has occured you have to have it's dna before and after and know the variables in between. The only thing I know of that we have a chance in observing such a thing is viruses and bacteria because of how fast they replicate. So I don't expect science to have to have an example to maintain it's course. I just want to check my beliefs in how I voted. I voted that it has occurred, but then realized later that I don't actually know of any examples.

 

[Sanoy]

I can think of plenty of examples of mutations.
- Hoxd12 and Hoxd13 and whale flipper evolution.
- Bmp2, fgf8, etc. and bat wing evolution.
- Sonic Hedgehog/Hand2 pathway and whale hind limb loss.
- SRGAP2C and ARHGAP11B in human brain evolution
- LCT/MCM6 regulation and human lactase production into adulthood.
- CCR5delta32 and HIV immunity
- EPAS1 in Tibetans allowing them to functiin better at altitude.

That isn't helpful without a description. Can you pick the strongest example and give a brief explanation that covers these two points. 1)How we know this is a mutation providing something new. 2) how this mutation provides a broad advantage. (IE It is not coupled with significant disadvantages, for example SSH is linked with holoprosencephaly)

 

[The IbanezerScrooge]

The Long-Term E coli Experiment
The Silver Fox Experiment
Widespread Lactose Tolerance in Humans
Genetic Adaptations to Diving in Bajau People

 

[Speedwell]

That isn't helpful without a description. Can you pick the strongest example and give a brief explanation that covers these two points. 1)How we know this is a mutation providing something new. 2) how this mutation provides a broad advantage. (IE It is not coupled with significant disadvantages)

Side note:

It sounds like may be caught up in the notion that in evolution, everything pretty much remains the same until once in a while a mutation comes along and makes a major change. That's not how it works. What happens is that each new generation of a species presents a range of variants to the environment for selection. These variants are randomly distributed in the population (think "bell curve") which is why the theory is called evolution by random variation and selection, not random mutation and selection. The periodic occurrence of genetic mutation feeds the process of creating randomly distributed variation, but is not the sole cause of it.

Now back to your regular programming.

 

[The IbanezerScrooge]

(IE It is not coupled with significant disadvantages, for example SSH is linked with holoprosencephaly)

Your goalposts are wiggling.

Evolution does not require new or more advantageous traits to appear in order to be "evolution". It is a creationist's unfounded requirement that evolution must always improve an organism. Any change in allele frequency is still evolution even if it results in the loss of a trait. It is true that natural selection tends to push populations toward having more advantageous traits for their environments, but there are cases where environmental changes cause populations to gain an advantage by losing a trait as well such as loss of vision in cave fish in order to conserve energy in development.

 

[Sanoy]

Your goalposts are wiggling.

Evolution does not require new or more advantageous traits to appear in order to be "evolution". It is a creationist's unfounded requirement that evolution must always improve an organism. Any change in allele frequency is still evolution even if it results in the loss of a trait. It is true that natural selection tends to push populations toward having more advantageous traits for their environments, but there are cases where environmental changes cause populations to gain an advantage by losing a trait as well such as loss of vision in cave fish in order to conserve energy in development.

And what is that goal scrooge?

#2 was mentioned in the original statement under what broad means.

 

[USincognito]

That isn't helpful without a description. Can you pick the strongest example and give a brief explanation that covers these two points. 1)How we know this is a mutation providing something new. 2) how this mutation provides a broad advantage. (IE It is not coupled with significant disadvantages, for example SSH is linked with holoprosencephaly)

I'm on my phone. Give me a litte time and I'll expand on them all for you.

 

[Sanoy]

I'm on my phone. Give me a litte time and I'll expand on them all for you.

Thanks. Just one is enough for me to justify my vote. So if there is one that hits those two conditions it works.

 

[The IbanezerScrooge]

And what is that goal scrooge?

#2 was mentioned in the original statement under what broad means.

Yes, I'm pointing out that your requirement of a "broad advantage" is not a requirement for evolution to have occurred. You seem to be setting the discussion up to continually request more specific cases as you're given examples that meet your first set of requirements until they reach some absurd level that is beyond the scope of evolution, at which point you declare victory in having "proven" evolution false.

Let's continue and see where it goes. Maybe you'll surprise us.

Do you have any comments on the examples I've provided?

 

[sfs]

So the question is, are there real examples where a life form has acquired a new feature, via mutation, that is broadly advantageous and has been selected? Here is what I mean by broadly. Sickle cell anemia may be an advantage against Malaria, but it's not a broad advantage because it is overall a health problem.

I'm not sure I can think of any trait at all, whether or not we can show it evolved, that is broadly advantageous by your definition, at least if you're looking at traits that differ between species. Every trait carries costs as well as benefits, and every beneficial trait is only beneficial in a some environments.

 

[Sanoy]

Yes, I'm pointing out that your requirement of a "broad advantage" is not a requirement for evolution to have occurred. You seem to be setting the discussion up to continually request more specific cases as you're given examples that meet your first set of requirements until they reach some absurd level that is beyond the scope of evolution, at which point you declare victory in having "proven" evolution false.

Let's continue and see where it goes. Maybe you'll surprise us.

Do you have any comments on the examples I've provided?

The requirements I'm giving are in reference to the vote I hastily submitted. My vote is in direct reference to the statement of the poll. Changing the statement doesn't help in regards to whether or not I have justification for my vote. I encourage you to reread the OP.

 

[The IbanezerScrooge]

The requirements I'm giving are in reference to the vote I hastily submitted. My vote is in direct reference to the statement of the poll. Changing the statement doesn't help in regards to whether or not I have justification for my vote. I encourage you to reread the OP.

It's a bad question, Sanoy. That's not how evolution is required to work. IMO, the question is unanswerable if you're required to use that definition. Sorry.

 

[Sanoy]

I'm not sure I can think of any trait at all, whether or not we can show it evolved, that is broadly advantageous by your definition, at least if you're looking at traits that differ between species. Every trait carries costs as well as benefits, and every beneficial trait is only beneficial in a some environments.

That's true, and could be overly restrictive. So let's divide it this way. Imagine a circle that represents the entire population. Inside that circle is a smaller circle which represents a group with a presently advantageous feature brought about by mutation. So the small circle might be sickle cell which is advantageous in regions with Malaria. If the mutation is broadly advantageous then it will be a *desirable by most of those in the larger circle. Would that be a good way to divide it?

* I choose desirable, because the situation concerns functionality along with behavior.

 

[xianghua]

. Any change in allele frequency is still evolution even if it results in the loss of a trait

according to that definition i think that 100% of creationists accept evolution.

 

[Sanoy]

It's a bad question, Sanoy. That's not how evolution is required to work. IMO, the question is unanswerable if you're required to use that definition. Sorry.

That may be true but that isn't at issue. My vote is either justified or not in reference to his question. I voted based on his definition, so my votes justification is tied only to his definition. It says nothing about the actual definitions of evolution.

 

[The IbanezerScrooge]

according to that definition i think that 100% of creationists accept evolution.

Exactly. And they should because that's what it actually is. But they don't because certain other members of their ideological circle fear that acceptance will damn their souls because it denies God so they misrepresent it to make it appear impossible.