A question about evolution

[Hespera]

Yes, about the adhesive properties found in choanoflagellates, and various proteins?

But the article also states, about choanoflagellates:


So why evolve? I mean, it would mean more food and longer living, but were they "happy" as they were? If they could flourish why would they evolve, I was under the impression an organism evolves out of necessity? It can't cope with this, a mutation helps, it survives. Unless multicellular development was a random mutation that proved not necessary, but extremely beneficial?

Oh, you can cope with this just fine. I understand the idea of "why evolve if you are happy as you are?". But its not like that.

You could say, well why did civilization arise, if there are people who are happy in the jungle?

The answer has to do with different circumstances.

Lets say that you have a species that has a mainland population, and an island population. The island population got there from the mainland, who knows how, but there are different ways it can happen.

Take an example from when I was in Belize. On the island, there have boa constrictors. On the mainland, they get like 12 feet long. On the island, they only get about 3 ft long. Even if you feed it a lot, it wont get big like on the mainland.

Well, the island is pretty small (different islands each have their own population, each a little different looking). The ones that can reach sexual maturity while still quite small will reproduce, the ones that need to get like 8 ft long first probably wont ever make it, there just isnt the supply of food for a population of big snakes. Reproductive success is what counts in the long run.

See how it works? Not ALL boas over their huge range changed in lock step, how could they? But an isolated population, specific circumstances, and they adapt to fit.

As for the main population, if what they are doing works, and there isnt a competitor who is better at it to push them out, well, no reason they should not last more or less forever unchanged. Like stone age man was doing ok till the ones with iron came around.

Anyway... does this make sense?


....becoming multicellular is the product of a great deal of time and a lot of mutations, not just one.....

 

[70x7]

The main reason why I think he did not distinguish between molecules and organisms is that there is no hard distinction.

The very first self-replicators would have been single molecules, probably small strands of RNA. Since these small strands of RNA were capable of imperfect replication, they could evolve. But were they alive? Well, that depends upon who you talk to. They were single molecules, after all. And they could only self replicate in an environment where they were continually heated and cooled within a bath with lots of nucleotides (such as a hydrothermal vent).

Eventually, as these little RNA molecules evolved, they'd add more and more functionality. Over time, they added enough to be called "alive" by everybody. But at what point did that happen? Was it the addition of this sort of protein or that? Was it the transition from RNA-based storage to DNA-based storage? Well, the exact transition point is pretty much arbitrary. So that's why it makes little sense to draw much of a distinction between life and self-replicating molecules. One is just more simple. That is all.

Anyway, if you want to know more about what scientists are doing to fill in the gap between primitive self-replicators and what most people call life, look up abiogenesis some time. There's a lot of info out there.

So I spent some time reading but I still fail to see where or how the creation of life occured. I read alot of theories by alot of scientists that do not all agree with each other. I think it is allowable to conclude from that there is no "answer" to how this happened, but mere faith in one or so of these ideas.
I do see alot of keywords like "could have formed" and "life appeared" and the like, so is it fair to say that there is no answer, but merely based off of assumption?

 

[MoonLancer]

If all life began with a single cell, what where the environmental conditions that would cause that cell to evolve into a multicelled organism?
And that multicelled organism into more complex organisms?

the reason people may be alittle short with you is that life did not start with a single cell. their were lots of stages even just to the first cell.

 

[Hespera]

So I spent some time reading but I still fail to see where or how the creation of life occured. I read alot of theories by alot of scientists that do not all agree with each other. I think it is allowable to conclude from that there is no "answer" to how this happened, but mere faith in one or so of these ideas.
I do see alot of keywords like "could have formed" and "life appeared" and the like, so is it fair to say that there is no answer, but merely based off of assumption?

well one thing, you are kind of expecting too much. You know, at the time of the American revolution people still thought that there must be a huge undiscovered continent in the south pacific! Germs are a way more recent discovery. You know, we are just people using our limited ability to try to figure out a very mysterious world. There probably are some things we wont ever know!

Nobody has at this time any way of knowing how life started. Its good sport for those interested, to try to figure it out. There are different ideas.
Nobody knows! So of course they say things like "could have" and people wont all wont be on the same page. It is all speculation (not assumption) , for those who are interested. Nobody has any "faith" in any of the theories.

Life appears to have started a very long time a go under conditions that are very very different form today. How do you find out what those conditions were? Pretty tough.... probably impossible. So how do you figure out how life started in unknown conditions? You cant, but people like to try anyway.

"Faith" in an idea is the Christian approach, and maybe they are right.


Not knowing how life originated does not invalidate the observation that AFTER it started, it proceeded to evolve into the forms we have now.

 

[Chalnoth]

So why evolve? I mean, it would mean more food and longer living, but were they "happy" as they were? If they could flourish why would they evolve, I was under the impression an organism evolves out of necessity?

Well, no. A species evolves no matter what. It may remain largely similar to its ancestors if it manages to fill a successful niche, but that doesn't mean it's stopped evolving. The very reason why we still have choanoflagellates around is that they fill a successful niche.

So, why might an organism evolve into something else even if it fills a successful niche? Well, most likely, it will diverge: part of the population will remain in the niche, because it is so successful. Another part of the population may happen upon a new way of surviving that makes it so it no longer has to compete with those in the very successful niche. For example, it may start migrating outward, away from the previously-successful niche, allowing it to survive in an area that its ancestors could not. There are other ways in which this can happen, of course, but geographical separation is a big one.

With sponges and choanoflagellates, as an example, just look at the differences: choanoflagellates are free-floating organisms. Sponges are anchored. By giving up their free-floating lifestyle, they were able to better filter the water and thus multiply better. But since they can't anchor anywhere, the free-floating choanoflagellates still had a successful niche to fill.

It can't cope with this, a mutation helps, it survives. Unless multicellular development was a random mutation that proved not necessary, but extremely beneficial?

Well, right, this is the way that most evolution is going to occur. After all, if it absolutely needs a mutation to survive, there's a possibility it may just go extinct instead.

 

[MaxP]

Thanks hespera, chalnoth, I have a basic idea know. I'll go get some books.

 

[Chalnoth]

So I spent some time reading but I still fail to see where or how the creation of life occured. I read alot of theories by alot of scientists that do not all agree with each other. I think it is allowable to conclude from that there is no "answer" to how this happened, but mere faith in one or so of these ideas.

There is no faith either. So far, the correct answer is that we don't know the precise details of how life formed. This doesn't mean we know nothing. Just that the evidence isn't definitive yet. The work is ongoing.

One thing that we do know, however, is that the formation of life was not instantaneous. It happened by small degrees over a great span of time.

I do see alot of keywords like "could have formed" and "life appeared" and the like, so is it fair to say that there is no answer, but merely based off of assumption?

There is no definitive answer, but it isn't based off of assumption. Right now the evidence isn't entirely clear, so we just don't know a lot of the details. Remember, "I don't know," is not an assumption. It's being honest.

 

[Hespera]

Thanks hespera, chalnoth, I have a basic idea know. I'll go get some books.

Any time! I hope you will do that.

To me, the earth and the living things on it is just so incredibly fascinating, I HAVE to know about what things are, how they work! Imagine how much you lose if you look at things and have no idea what they really are, and how they relate to eachother. A person who knows no biology or geology goes outside, he doesnt really know any more about it than a pigeon knows about what a city really is about. That is how i see it.

Im stuck in the midwest right now but I hope hope hope i some day can also spend some time on the ocean, and learn about that. You know, a sailor can read the waves and the rest of us just see water. i want to know how to do that too!

Well good luck with your reading, and i hope you too will start to see the world in new ways.

 

[70x7]

One thing that we do know, however, is that the formation of life was not instantaneous. It happened by small degrees over a great span of time.

And how do you know that being that you said this....

There is no definitive answer, but it isn't based off of assumption. Right now the evidence isn't entirely clear, so we just don't know a lot of the details. Remember, "I don't know," is not an assumption. It's being honest.

edit..

One more question, if the "evidence isn't entirely clear" then do you suppose God COULD have done it?

 

[Hespera]

And how do you know that being that you said this....



edit..

One more question, if the "evidence isn't entirely clear" then do you suppose God COULD have done it?

Far as i am concerned, god could have done it. if there is a god...!

After life started, if began evolving. Simple.

Evolution is about how life developed and changed. If people could get past the idea that for god to be real, evolution cant be, and vice versa for that matter, there would be very little to argue about.

And I think that those who dont want to see evolution as real would find they have been wasting a lot of energy fighting against seeing one of the most interesting things there is.

 

[Split Rock]

So I spent some time reading but I still fail to see where or how the creation of life occured. I read alot of theories by alot of scientists that do not all agree with each other. I think it is allowable to conclude from that there is no "answer" to how this happened, but mere faith in one or so of these ideas.
I do see alot of keywords like "could have formed" and "life appeared" and the like, so is it fair to say that there is no answer, but merely based off of assumption?

The main thing to understand about Abiogenesis, is that there is no Abiogenesis Theory. Just some plausible hypotheses.

 

[Split Rock]

One more question, if the "evidence isn't entirely clear" then do you suppose God COULD have done it?

I suppose so. But that would not be a scientific answer we can test.

 

[MaxP]

I suppose so. But that would not be a scientific answer we can test.

I personally don't think we can test the origin of the universe from within the bounds of the universe.

 

[Hespera]

The main thing to understand about Abiogenesis, is that there is no Abiogenesis Theory. Just some plausible hypotheses.

Its also not like Descartes saying "I think therefore I am", then basing everything else on that.

Or the Bible saying "In the beginning God made ..."

If either of those premises is wrong then nothing that follows is going to be right either.

Big Bang is a maybe, the best that science can come up with for now. If the premise of "big bang" turns out to be wrong, well, that doesnt collapse all of astrophysics. Just means it started some other way.

Abiogensis of SOME kind had to have happened, whether supernatural or otherwise.

Any notion of how it happened is a maybe. One of the ideas might be right, but however that goes, it doesnt collapse anything about the nature of evolution.

 

[Chalnoth]

And how do you know that being that you said this....

Well, just because we don't know some things doesn't mean that we know nothing. For example, we know that all of the building blocks of life would have formed naturally in a variety of locations in the early Earth. We know that those building blocks can spontaneously combine to make larger, more complex molecules. We know that some of those molecules can self replicate. And we know that self-replicating molecules, if errors are allowed in their reproduction, will lead to evolution.

Now, we don't know precisely how this occurred. We don't know what sort of self-replicating molecules were the first, for instance. We don't know how the transition was made from this simple self-replicating molecule to the now nearly ubiquitous DNA-based life. We don't know how the various additional mechanisms like those related to metabolism were added.

So there are some things that we do know, and a lot of details that we do not know.

One more question, if the "evidence isn't entirely clear" then do you suppose God COULD have done it?

Obscenely unlikely. I see no more reason to attribute the origin of life to a deity than I see to attribute lightning to one. Just because I am not personally aware of the details of the formation of life in no way means that I should attribute it to a supernatural cause. From what little I understand about life, it's just chemistry. Very complex, very amazing, very beautiful chemistry. But chemistry nonetheless.

 

[Chalnoth]

I personally don't think we can test the origin of the universe from within the bounds of the universe.

Yes, that may turn out to be very, very difficult, if not impossible. The primary problem is that we can't even see the whole of the universe: the rate of expansion of the universe over time hides both the distant past and things that are far away. I sincerely hope that we'll be able to determine it somehow, but I recognize that it may not actually be possible.

 

[70x7]

Just so I understand...

Just because we cannot scientifically prove something does not mean that it does not exist right?
We all have the ability to love but can science prove it? Scientific method seems to not work here, so does love exist? But, we KNOW it exists because we can feel it if we choose to. Hmm....I hope you can see where I am going with that.

Evolution. Are we talking the definition meaning simply "change within species" or are we talking "changing into other species".
No doubt that mutation occurs and natural selection happens, but I have yet to see any subject of one kind "evolve" into another.

 

[Chalnoth]

Just so I understand...

Just because we cannot scientifically prove something does not mean that it does not exist right?

No, but it does mean that we have no reason to believe it exists.

We all have the ability to love but can science prove it?

Easily.

Scientific method seems to not work here, so does love exist?

Why shouldn't it? All you have to do is define specifically what is meant by "love", and the rest is a relatively straightforward exercise.

Evolution. Are we talking the definition meaning simply "change within species" or are we talking "changing into other species".

The only difference between the two is time.

No doubt that mutation occurs and natural selection happens, but I have yet to see any subject of one kind "evolve" into another.

Just because you haven't doesn't mean scientists looking carefully at the world have not. Here's a good example that was observed recently:
http://www.physorg.com/news127667797.html

They took some lizards and transplanted them on a new island. Islands are known to accelerate evolution due to their isolation. We then waited 30 years, and went back. What did we find? Well, the lizards that had been transplanted were now largely herbivores (their ancestors were insectivores). Their jaws got bigger and more powerful to better aid in chewing tougher plant matter, and they developed cecal valves in their digestive tracts for the fermentation of plant matter, complete with symbiotic parasites to do the fermenting.

This is just a superb example of macroevolution in progress: first we have significant change in body shape and in behavior (insectivore to herbivore), second we have the development of a new sort of body structure. It's everything you could ask for in an observed speciation event!

 

[Hespera]

Just so I understand...

Just because we cannot scientifically prove something does not mean that it does not exist right?
We all have the ability to love but can science prove it? Scientific method seems to not work here, so does love exist? But, we KNOW it exists because we can feel it if we choose to. Hmm....I hope you can see where I am going with that.

Evolution. Are we talking the definition meaning simply "change within species" or are we talking "changing into other species".
No doubt that mutation occurs and natural selection happens, but I have yet to see any subject of one kind "evolve" into another.

No, its impossible, as has been pointed out SO many times, to prove something does not exist.

Lets see... first you say that lack of evidence is no reason not to believe something. Then you ask for impossible evidence (that you personally see one species evolve to another) before you will believe something.

No fair.

I have a feeling you dont really know what the word "species " means.
A cow and a buffalo are different species. But they are closely related, and can breed. What is or isnt a "species" is a judgment call. I saw a book that identified several different species of grizzly bears just in yellowstone park. Well, there are no doubt several color variations. Now only one species is recognized. The there are 'subspecies", even less of a bright line distinciton.

If the various breeds of cows or dogs or chickens etc had occurried due to natural forces, like there was the Isle of The Holestein and on the mainland its all Herefords... then the Holestein would get classified as a seperate species.

Surely you do not doubt that natural selection will create seperate species? Related animals, they can still interbreed,but have differnt physical characteristics?

(oh... did you SEE the basic auroch turn into all the breeds of modern cows? do you doubt that it happened? do you think only people can affect animals in such ways?)

Small scale physical adaptations in such things as color, fur density, physical size, leg length etc etc are just so obvoius and so common that
to deny it is to live outside of reality.

That leaves the problem of... how far can this go? I see creationsists like to say ok "micro" but not "macro" evoluiton. But... why not? You just keep on making little changes little changes and after a while you have something way different.

But here is what non biologists REALLY dont get, is the commonalities among all living things. (we will stick to vertebrates here tho)

When you study the structure of the vertebrates,you see how we are all related. The reptile is not so differnt from an amphibian... look how the skeleton, the muslces, the circulatory system, the nervous system, they all match up. The bird is not so different from the reptile. People have a lot in common with, yes, fish.

If you actually ever really do look at comparative anatomy and the fossil record, and think about it, you will see that there is just a long continuous series of little changes. It isnt like one animal suddenly turns into something totally different. Heck, the wolf didnt suddenly turn into the beagle. Even if it had, they are far from totally different. Mammals are not totally different from reptiles either.

I understand the problem you have, that you nor anybody sees one animals change into another.

You are just looking for the wrong thing. When you see that, you will understand the whole process way bettter.

 

[Split Rock]

Just so I understand...

Just because we cannot scientifically prove something does not mean that it does not exist right?
We all have the ability to love but can science prove it? Scientific method seems to not work here, so does love exist? But, we KNOW it exists because we can feel it if we choose to. Hmm....I hope you can see where I am going with that.

Actually, we can to some extent measure love. We know what hormones are associated with love and what hormones are released during both sexual activity and non-sexual affection (such as hugging, etc.). We know there are different brain chemistries associated with different emotions.

Evolution. Are we talking the definition meaning simply "change within species" or are we talking "changing into other species".
No doubt that mutation occurs and natural selection happens, but I have yet to see any subject of one kind "evolve" into another.

Speciation has been observed both in nature and in the lab. As far as one "kind" evolving into another "kind," you will have to give us an explanation of what a "kind" is. Good luck with that.