Evolution: The Scientific Evidence

[jinydu]

Originally Posted by Jwb52z

If evolution basically amounts to a bunch of random mutations that somehow turn out to be beneficial and passed on, has anyone ever figured out why it happens without something we can tell making it happen? I know the mutations are from DNA copying incorrectly, but shouldn't there be something causing it? Evolution can't simply be a willing physical response, the way I understand it, to a changing environment without something "knowing" it needs to happen. I mean, I don't see a reason that a being would suddenly develop something beneficial as just a coincidence. Has anyone been able to even theorize what the impetus for evolution actually is beyond what we can see happening?

First of all, there are many ways that genomes can be altered, not just mutation. Of course, there are the more famous point mutations, where a single base pair is added, deleted or changed. There are other ways as well; for instance genetic recombination (genomes from two different organisms exchange base pairs, occurs during sexual reproduction). If you look earlier in this thread, you will find that sometimes, one organism devours another; and the DNA of the devoured organism gets absorbed into the DNA of the devourer. And of course, as you may have learned in biology classes, viruses reproduce by injecting their DNA into host cells.

Originally Posted by Jwb52z

I mean, I don't see a reason that a being would suddenly develop something beneficial as just a coincidence.

And why not? Why do you find natural selection to be an unsatisfying explanation?

[Jwb52z]

Originally Posted by jinydu

And why not? Why do you find natural selection to be an unsatisfying explanation?

I know you won't like my answer, but here it is anyway. I don't like the idea of a universe or existence without an absolute ultimate goal or point to it. To me, it makes everything a big pile of pointlessness. I believe in coincidences in daily life, but not for things that are part of life itself. Why is the idea, for people who believe in macroevolution, that things just happen or that the universe just "became reality" or "started" any easier to accept than it had a purpose and a being started it? Is it really just a matter of "if I can't see it, I don't want it to be real"? By "see" I mean perceive in any way. It seems to me that people who believe in evolution, most of the time anyway, don't seem to be able to believe anything beyond the human senses unless someone shows them some kind of scientifically supported paper or something like this. I guess it's just me because I don't understand requiring proof for everything. Also, some people have said, "such and such wouldn't require God". What I want to say is that just because science might have discovered that "it doesn't require God" that doesn't mean that it didn't involve God anyway. Lots of things can be done without a certain element being required, but sometimes it is anyway.

[cheesehead]

Originally Posted by Jwb52z

If evolution basically amounts to a bunch of random mutations that somehow turn out to be beneficial and passed on, has anyone ever figured out why it happens without something we can tell making it happen?

But we can tell several things that make mutations happen!

(a) Radiation. Every second, you have various types of penetrating radiation passing through your body that are capable of destroying, disrupting or rearranging the particles, atoms, atomic bonds, and molecular bonds that make up your DNA.

Cosmic rays are subatomic particles that have a great deal of kinetic energy when the reach the Earth. Even if the first other particles they hit are in our atmosphere above us, the collision usually produces other energetic particles that may reach our bodies.

Radon gas accumulates in basements in certain areas (such as here in SE Wisconsin) that have radium in the groung below them. When radon decays radioactively, it may send a gamma ray or energetic particle through the body of someone living in the house.

And there is other radiation coming from the ground/rocks in most areas from small amounts of other radioactive substances.

Since DNA comprises only a minute part of the molecules in your cells, most radiation hits will not cause a mutation (though it may cause other damage). If DNA is affected, but is not in a germ cell (female egg or male sperm), the resulting mutation won't be passed on to your descendants. But once in a while, DNA that can be passed on to your descendants may be mutated by radiation.

(b) Chemicals. Various chemicals can react with DNA to change it if the chenical comes in contact with the DNA. We most often hear about this because the damage results in cancer. But if the damage is to DNA in a germ cell (see above), it can be a mutation passed on to children.

I know the mutations are from DNA copying incorrectly

As you can see now, that's not the _only_ way mutations arise.

Evolution can't simply be a willing physical response, the way I understand it, to a changing environment without something "knowing" it needs to happen.

But, contrary to what a creationist might claim, the response doesn't have to be "willing" or planned. Most mutations, it turns out, are harmful, but a few may happen, by chance, to be beneficial in that the individuals bearing it may be better adapted to a changed environment.

I don't see a reason that a being would suddenly develop something beneficial as just a coincidence.

No reason is required. That being is just the lucky recipient of a beneficial mutation. Don't forget that most mutations are "un"lucky. We focus on the minute portion that are beneficial, but most are harmful, and those individuals tend to have fewer or less successful descendants. There are lots of losers in the evolution lottery.

Has anyone been able to even theorize what the impetus for evolution actually is beyond what we can see happening?

Yes. See above. But creationists probably won't help you understand that, and would be delighted to let you continue to think that evolution is mysterious and without explanation.

- - -

I want to respond to your next post ("I know you won't ...") and have what I consider a good answer because I went through basically the same thing myself (and _survived_ and _thrived_!), but don't have time right now.

[xilman]

Originally Posted by cheesehead

Don't forget that most mutations are "un"lucky. We focus on the minute portion that are beneficial, but most are harmful, and those individuals tend to have fewer or less successful descendants. There are lots of losers in the evolution lottery.

It's worse than that, he's dead Jim.

To elaborate: most mutations that have any significant effect are fatal. Most fertilized ova with a significant mutation, whether it comes from the mother or the father, don't get as far as sprouting/hatching/birth (delete as appropriate). If you carry a significant mutation and get as far as being a larva or seedling or pup or whatever the conventional term is for your species, the odds are still against you being able to live long enough to have offspring to whom you are able to pass on your mutation.

It's not in the least bit surprising that only the beneficial minority get much of the attention. Those which get the remainder are those that survive long enough to be noticed by anyone other than professional geneticists.


Paul

[brunoparga]

Originally Posted by Jwb52z

I don't like the idea of a universe or existence without an absolute ultimate goal or point to it.

Well, the Universe does have a telos (this is the word by which the Ancient Greeks referred to the ultimate goal, end or point of something).

That'll be either:

(a) Crunching back via gravity to its original, all-energy-packed-in-a-ludicrously-small-space state;

or

(b) Expanding forever til such time when entropy finally distributes all of the energy in the Universe uniformly, which implies nothing can happen anymore except the perpetual expansion itself.

Oh, there's also this theory, which suggests the expansion of the Universe will eventually override all of the forces we currently know (e.g. gravity) and everything will be torn apart, our very selves included.

Now do you like this idea?

Bruno

[Jwb52z]

Originally Posted by brunoparga

Well, the Universe does have a telos (this is the word by which the Ancient Greeks referred to the ultimate goal, end or point of something).

That'll be either:

(a) Crunching back via gravity to its original, all-energy-packed-in-a-ludicrously-small-space state;

or

(b) Expanding forever til such time when entropy finally distributes all of the energy in the Universe uniformly, which implies nothing can happen anymore except the perpetual expansion itself.

Oh, there's also this theory, which suggests the expansion of the Universe will eventually override all of the forces we currently know (e.g. gravity) and everything will be torn apart, our very selves included.

Now do you like this idea?

Bruno

No, actually, that doesn't make it any better for me. Honestly, that wasn't my idea when I used the word "point" or "goal". To me, an eventual happening is not a goal. Maybe I should have used the word "purpose" to get the idea across better. These words, as I understand them, have a connotation that nothing in science seems to have at all.

[jinydu]

Originally Posted by Jwb52z

I know you won't like my answer, but here it is anyway. I don't like the idea of a universe or existence without an absolute ultimate goal or point to it. To me, it makes everything a big pile of pointlessness. I believe in coincidences in daily life, but not for things that are part of life itself.

Well, perhaps you could ask yourself this question:

What is the difference between an "eventual happening" and a "purpose"? Or to rephrase the question more precisely: Given any system whose end-state is known to you, what criterion can you use to decide whether it is "purposeful" or not?

Originally Posted by Jwb52z

Why is the idea, for people who believe in macroevolution, that things just happen or that the universe just "became reality" or "started" any easier to accept than it had a purpose and a being started it? Is it really just a matter of "if I can't see it, I don't want it to be real"? By "see" I mean perceive in any way. It seems to me that people who believe in evolution, most of the time anyway, don't seem to be able to believe anything beyond the human senses unless someone shows them some kind of scientifically supported paper or something like this.

Because the hypothesis that the Universe "just started" only requires believing in something that we know exists (the Universe), while believing that God created the Universe requires believing in something that we are not sure exists (God).

Originally Posted by Jwb52z

I guess it's just me because I don't understand requiring proof for everything.

Because otherwise, you may end up believing in a lot of false things.

Originally Posted by Jwb52z

Also, some people have said, "such and such wouldn't require God". What I want to say is that just because science might have discovered that "it doesn't require God" that doesn't mean that it didn't involve God anyway. Lots of things can be done without a certain element being required, but sometimes it is anyway.

True, but science is just following Occam's Razor: If you don't need to invoke a certain assumption, then don't. Right now, the light in my room is on. I could believe that this is because the electrical system is working correctly; or I could believe that there is an invisible fairy making it run. I prefer the first explanation, although I cannot definitively disprove the second one.

[Jwb52z]

Originally Posted by jinydu

Well, perhaps you could ask yourself this question:

What is the difference between an "eventual happening" and a "purpose"? Or to rephrase the question more precisely: Given any system whose end-state is known to you, what criterion can you use to decide whether it is "purposeful" or not?

OK, this was my fault again, by "eventual happening" I didn't mean "I knew it was gonna happen". I meant something that simply occurred as an event, like, "it just happened" as a statement of fact. Some things, as you know, happen anyway no matter what. Purpose, on the other hand, would have a general plan and a reason and a direction behind it. Those things would require thought by "something intelligent" on some level.

Originally Posted by jinydu

Because otherwise, you may end up believing in a lot of false things.

So, basically, what this tells me is that scientific belief is just an effort to reduce the number of times a person is wrong? That's quite an idea if that's what it boils down to and it explains ALOT.

[brunoparga]

Originally Posted by Jwb52z

So, basically, what this tells me is that scientific belief is just an effort to reduce the number of times a person is wrong? That's quite an idea if that's what it boils down to and it explains ALOT.

I don't disagree with that, I'd just draw this picture in a larger scale.

First, I wouldn't use the expression "scientific belief". Think of a kid who wears a Superman uniform and jumps out of his window, believing he can fly. We know he cannot, and he'll fall down and suffer severe injury and perhaps die. It's just the same with other scientific areas, say, cosmology or evolution. The scientific evidence is there, and it remains there regardless of whether we believe it or not.

I know this wasn't probably your intention, but the way you mentioned "scientifically supported papers" in your first post seemed to me like science was a sort of a secret cult with secret knowledge. It is not; in principle, every piece of evidence used in every scientific paper is publicly available, and you could check it for yourself. Of course, it is actually a bit more complicated than that; a paper about a genome, for instance, might require that you know how to extract the DNA from a cell; a research on the pharaohs of ancient Egypt might require you to travel to Egypt.

Given those caveats, I'd say the scientific method allows not just one person to reduce the number of times they're wrong; it allows the entire society to advance our knowledge, and to make better decisions - for instance, knowing that human action has already made carbon dioxide levels in the atmosphere raise well above their natural, pre-human range might lead us to question the way we generate and use energy and our environmental resources, and ultimately provide us means of keeping the planet inhabitable for future generations.

Bruno

[Fusion_power]

I'll boil it down even further. There are people in this world who are comfortable with the unknown. There are other people who are not.

I'm still waiting on someone to give any reasonable answer why humans changed so drastically so fast. There was a severely limited population. The number of mutations that could occur was restricted by the population size. How on earth do you think that "evolution" was able to produce modern humans in a mere million or so years?

Look back at Xilman's post which points out that the great apes have not changed significantly in that million years. What happened that caused humans to change? I'll spell it out even better by saying that its impossible to justify the existence of modern humans based entirely on evolution. What happened? Why?

I am certain that as we compare the genomes of humans vs apes vs mammals we will in time come to understand the nature of the changes much better than we do today.

Fusion

[jinydu]

Originally Posted by jinydu

Well, perhaps you could ask yourself this question:

What is the difference between an "eventual happening" and a "purpose"? Or to rephrase the question more precisely: Given any system whose end-state is known to you, what criterion can you use to decide whether it is "purposeful" or not?

Originally Posted by Jwb52z

OK, this was my fault again, by "eventual happening" I didn't mean "I knew it was gonna happen". I meant something that simply occurred as an event, like, "it just happened" as a statement of fact. Some things, as you know, happen anyway no matter what. Purpose, on the other hand, would have a general plan and a reason and a direction behind it. Those things would require thought by "something intelligent" on some level.

What if I rephrase the question again, changing the word "criterion" to "test"?