Proof of Evolution: Logical Evidence

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In summary: Pilus thing to happen, the two bacteria need to be of the same species, and the pilus needs to be there. And even then, its not very common.In summary, while DNA can get into other bacteria, it usually doesn't result in anything happening between the two species. There is a chance for bacterial sex to occur, but its not very common.
  • #1
Another God
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Evolution not proven? here is its logical proof:

1. The current theory of evolution states that any system where there is hereditary information, slight alterations of that information, and a selection pressure for the best system of hereditary information, evolution will occur.

2. DNA is the hereditary code, passed down from generation to generation in an essentially static form.

3. Mutations occur irregularly in all forms of DNA, in a myriad of different ways.

4. In nature, at every level, more organisms are given birth to/replicated/produced, than are able to surive to sexual/replicable age.

Conclusion
5. Therefore, Evolution occurs.



While I believe this proof is unquestionable (prove me wrong), it doesn't address whether or not evolution explains the variety of life we can see. It just proves that Evolution is an unquestionable fact of life.
 
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  • #2
You know, this is a very important point (kudos, AG). Evolution has been proven to occur. I also really appreciate the mention (at the bottom of your post) of the fact that it does not account for the variety of life that we see around us.

In short: Evolution is an observable fact, but we can only formulate hypotheses (some even become theories) as to the variety of life that is currently to be found in the Earth.
 
  • #3
Isn't the fact that we are able to make children genetically composed of two people proof enough of evolution? Or say, the fact that we are able to breed certain strains of organisms in order to get new phenotypical characteristics?

And euhh, AG? Since when is DNA passed down from generation to generation in an essentially static form?? There are on average 40 cross-overs in our genome per meiosis. The process of meiosis essentially requires cross-overs to occur. I am not sure about the selection process after these 40 meiosis, how many can actually form a zygote..
 
  • #4
Are there records of different variations throughout relatively recent human history that imply evolution occurring?
 
  • #5
Well, I guess you can take the variation in skin colour or lung capacity etc across the human race as evidence for a drive towards diversity. The increased size of US people over past years, or earlier appearance of puberty is also evidence, though I don't think it is entirely genetic.
 
  • #6
I'm beginning to doubt genetics is the first thing that "causes"(so to speak) evolution.
 
  • #7
Huh? Whats to doubt? Evolution occurs through genetic mutations. Observable, testable, obvious fact.

That is an essential part of the proof above.

And:
The member formerly known as theOwl :

Perhaps essentially static sounds too strong, but I just couldn't think of a better adjective at the time.

Still, the idea remains I think, because even though there is so much crossing over in meiosis, the DNA which is crossing over is so damn similar (almost identical considering the bulk size of it) the change is negligable.

Besides, meisis is only a fraction of the evolutionary chain. A recent fraction.
 
  • #8
Bacterial sex is particularly interesting. It's as though those bacteria are throwing around code and using it to build entirely new bacteria. Oh wait, that's exactly what it is. Even crosses species bariers completely.
 
  • #9
Originally posted by CJames
Even crosses species bariers completely.
Well, I wouldn't say that exactly.

I asked a question just last week to one of my Microbial Genetics lecturers about that actually. One question we were asked in a test was about whether DNA could jump from species to species etc. And its not as obvious as it may seem.

Firstly, of course DNA is just DNA. Its the same in all species, so if it gets into any species genome, then its in there and it will be copied.

What needs to be considered though, is
1. How it gets in there
2. Whether it will do anything once it gets in there

For 1, naked DNA can get into Bacteria, but certain conditions need to be present for that to happen, so it is not frequent. Plus, once it gets into the bacteria, it still needs to get into the Chromosome. This is even harder, and not something which usually 'Just happens'.

The other way DNA can get into other bacteria is through Conjugation (this is probably the type of DNA u are referring to when u talk of Bacterial Sex). COnjugation occurs when a bacteria contains a series of genes which encode for this thing caleld 'The Sex Pilus'. When they have these genes (usually on a plasmid), a short lived bridge forms between it and a neighbouring bacteria, and a plasmid can pass from one to the other.

..

I could go into a lot of detail, but well, I don't think anyone is really that interested. Actually, you might be. If anyone is interested, raise your hands, and I will start a whole new topic.

But to get to the point of it, bacterial 'sex' as such, doesn't occur between different species very much at all. For the Sex Pilus to form, there are the usual sorts of recognition things which need to happen. If there are two different species, then they won't recognise each other.
 
  • #10
I raise my hand.

Anyway, no, I wasn't implying that it happens often, even though it sounds that way. But it is one of the big parts of bacterial evolution, is it not? Every once in a while a bacterium can pick up a stray plasmid. Am I right? I could just be having bad memory again.
 
  • #11
Well..um..i guess it could be.

I'm not really sure what has more influence on evolution, but I can tell you that plasmids are definitely an obvious phenomenon. They have a quick recognizable phenotypic effect when present, and are very convenient when it comes to genetic engineering stuff.

We are currently doing a lab in Microbial Genetics which is using a plasmid to mutate a E Coli bacteria (A very normal experiment really), and the plasmid which we are using has been almost completely engineered to do exactly what we want it to do. Its all so damn clever when u understand it.


For plasmids to have any sort of permanent effect on evolution though, they need to have a transposon on them, or some method of integrating themselves into the chromosome permanently.

So yeah, when this happens, i guess it could very easily be beneficial to the evolution of bacteria.
 
  • #12
g'day!

that is an interesting proof of evolution, however it doesn't consider other reasons for evolution, i am thinking of the non biological ones. evolution is always assiociated with natural selection, the fitter have more babies etc. but there are other forces promting evolution that have nothing to do with the 'selection pressure for the best system of hereditary information' as you rightly put it. physical forces like thermodynamics also have an effect on evolution.

The universe 'prefers' systems that turn collected energy into difuse energy, in this way systems like individual species or ecosystems will tend towards greater energy consumption for no apparent survival reason. the only evidence I've heard for this argument is that systems that have more time to evolve are the biggest energy wasters, just look at humanity!

cheers!
 
  • #13
I know it is related, but I can't manage to get my head around exactly how this affect evolution.

Sure, laws of thermodynamics affect everything, but, what explicitly are u getting at which can't be assumed as 'Evolution works as explained in the proof, under the laws present in our universe.'?
 
  • #14
because your proof is based on the importance of the transmission of genetic information, ie the ability of a species to live long, prosper and reproduce. the difference with the thermodynamic theroy is the cause of this transmission, both theories admit the ability of a trait to be passed on to the next generation (this is the 'how'), but with 'classical' evolution the reason for evolution (the 'why') is this exact ability to pass on traits as much as possible, where as with this 'other' evolution the 'why' has nothing to do with the 'how'.

at least that's how i understand it... crazy huh?

trust the physicists to complicate things! :wink:
 
  • #15
oh yeah... I'm confused.
 
  • #16
oh yeah... I'm confused.
Heh. I'll join you. We'll start a club.

While I believe this proof is unquestionable (prove me wrong), it doesn't address whether or not evolution explains the variety of life we can see.
I'm not seeing that. Like mitosis, or nuclear fission, evolution is a geometric progresson. If mutations occur enough that you have ANY new species evolving, your world should quickly fill up with MILLIONS of different species. That appears to be exactly what happened.
 
  • #17
I'm afraid I didn't see where this apparent confusion started. What is it that confused everyone?
 
  • #18
Originally posted by Another God
While I believe this proof is unquestionable (prove me wrong), it doesn't address whether or not evolution explains the variety of life we can see. It just proves that Evolution is an unquestionable fact of life.

This proof explains evolution in terms of a particular ecological niche or adapative landscape. Given there are a miriad of ecological niches and that adaptive lanscapes are constantly changing, an similar number of species will result.
 
  • #19
I think the big issue in this type of discussion is to separate evolution from creationalism.. evolution is proven, but the fuzzy part is how an a photoreceptor evolved into an eye, not how how a gliding squirrel got to its skin flaps to glide (probably the route by which birds evolved wings).

Mutations happen, ever seen the deformeties that are encountered in fetuses/embryo's? Mutations happen, diseases are genetic, aggregation of mutations in a certain direction will lead to evolution. The major factor influencing evolution is environmental pressure. The squirrel with the larger skin flaps is able to make it to the next tree without crashing into the ground, if selective pressure is high enough, the trait will be passed down.

How about comparing genomes? Only 1% of the genes in the mouse have no homologues in humans..

To address MajinVegeta's original question about human evolution.. how about Africans being long and lean and Eskimo's being short and chubby? How about sickel cell anemia being prevalent in Malaria-infested regions? Skin color? All these things have evolved for a reason.
 
  • #20
I'm afraid I didn't see where this apparent confusion started. What is it that confused everyone?
Steppenwolf's posts. They don't make any sense.
 
  • #21
You know, this is a very important point (kudos, AG). Evolution has been proven to occur. I also really appreciate the mention (at the bottom of your post) of the fact that it does not account for the variety of life that we see around us. In short: Evolution is an observable fact, but we can only formulate hypotheses (some even become theories) as to the variety of life that is currently to be found in the Earth.

I don't like this. He didn't say that evolution doesn't account for the biodiversity we see around us, simply that the question of whether it does is unresolved. Evolution is still the only credible scientific theory we have to explain Earth's biodiversity.
 
  • #22
ACTUALLY, natural selection is not THE way evolution entirely works; natural selection is one of several factors that cause evolution to happen, the others being sexual selection, genetic drift, gene flow, and mutation.
 
  • #23
Originally posted by GlamGein
ACTUALLY, natural selection is not THE way evolution entirely works; natural selection is one of several factors that cause evolution to happen, the others being sexual selection, genetic drift, gene flow, and mutation.

I don't think anyone here has said otherwise.
 
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  • #24
well, Pauly, I agree that I was a little quick on the uptake of replying to a message that was certainly not at the end of the thread, but as a matter of fact, I don't think anyone here really understands evolution very well. My point being, that there is no point in debating a matter if you don't understand the fundamentals.
But thanks for the succinct comment.
 
  • #25
Originally posted by zk4586
I don't like this. He didn't say that evolution doesn't account for the biodiversity we see around us, simply that the question of whether it does is unresolved. Evolution is still the only credible scientific theory we have to explain Earth's biodiversity.

This is what I meant, that it hasn't resolved the issue (yet?).
 
  • #26
Well, my comment about this proof saying nothing about whether or not Evolution actually HAS created the myriad of creatures around us is exactly what it seems. This proof doesn't say anything about that conclusion. This Proof only attempts, and it would seem (if public ocncensus is anything to go off) that it has suceeded in doing so.

So we all seem to agree, evolution must occur. Evolution is a mathematically proven fact.

Now, accepting that premise, whether evolution is accountable for the life around us or not is something which needs to be argued for from some completely different perspective. Generally, I have confidence that it is the explanation for the life around us, based on a logical connection of Fossil Record showing progression, billions of years of time, relatedness between organisms, and occams razor.

In other words, considering the evidence presented showing the slow progression of related organisms throughout time, and the fact that we know some process factually exists which can explain this (and there seems to be only one), it is an obvious conclusion to fit that explanation to the evidence.

This, unfortunately, is not a 'proof' as my initial post was, but it is quite rational none the less.
 
  • #27
Originally posted by GlamGein
I don't think anyone here really understands evolution very well.

I'm not going to stick up for everyone, but I will say that there are many people contributing to this thread that understand evolution very well. If you find something wrong with their comments I'd say it is due to a lack of clarity, not knowledge.
 
  • #28
Originally posted by Another God
Conclusion
5. Therefore, Evolution occurs.
And?
 
  • #29


Originally posted by Lifegazer
And?

What else is there to say? Evolution occurs.
 
  • #30
Evolution proven? Yeah, right.

Children receive half of their genetic information from the male parent and the other half from the female parent. No new information coming into existence = no evolution. For example, let's say we hypothetically go to Japan and reproductively isolate those who look asian (black hair, epicanthic fold above the eyes). If they only breed among themselves, their children will also look asian, and their children will look asian, and so on and so on...forever. This hypothetical population (and the human population in general) represents a closed system with no possibility of evolution ever occurring.
 
  • #31
That's where mutation comes in.
And even if the characteristic is not immediately visible, it can still exist according to genetics as an recessive allele among minorities of the population. But narrowing down the gene pool by restricting reproduction and cross-overs does indeed slow down adaptability. A recent example is the vulnerability of the banana plant to certain plant diseases due to centuries of asexual breeding by humans.
 
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  • #32
Never heard of Recombination?

Thank you O Great One for challenging one of the premises of my argument. But as FZ has already mentioned, your counter argument isn't correct, simply because it is not the case that no new genetic information comes into the system.

When those two halves of the parents combine to make the children, Recombination occurs, and 'Cross Over Events' can cause the DNA to be moved around in unpredicatable ways. Thse changes can disrupt genes, or just change something which has some sort of effect.

As well as that form of mutation, there are point mutations (where a single base is changed), there are deletions (where sections of bases are deleted), there are insertions (opposite of deletion), duplications (the same section of DNA ss copied and reinserted again) and a variety of other mutation events which can change subtle things, which may have no effect, negligable effect, drastic effects, or subtle effects which aren't noticed until several other mutations have added up on top of them.

I am sure that I did mention mutations in my original argument for evolution occurring, if you do not now understand what mutation is, how it works, or why it is important to evolution, then please, keep asking.

.

Evolution Occurs.
 
  • #33
And this ability for mutation (which proves that Evolution happens) can account for the variety of life that we see around us today, but it doesn't have to.
 
  • #34


Originally posted by O Great One
Children receive half of their genetic information from the male parent and the other half from the female parent. No new information coming into existence = no evolution. For example, let's say we hypothetically go to Japan and reproductively isolate those who look asian (black hair, epicanthic fold above the eyes). If they only breed among themselves, their children will also look asian, and their children will look asian, and so on and so on...forever. This hypothetical population (and the human population in general) represents a closed system with no possibility of evolution ever occurring.

Just to add to what FZ+ and A.G. said...

There are many examples of reproductively isolated human populations and each has distinctive traits (e.g., Australian aborigine vs. Pacific islander vs. S. Am. rainforest tribe vs. Inuit, etc.). Note that each variety of human is believed to be tied back to a common ancestor in Africa. I.E., that original population spread out across the world, became isolated from the original population for many, many generations, and then changes in the separated gene pools added up to give us our current variety (races).

IIRC, there are genetic differences in some groups that are not present in other groups. There is some effort to use these genetic markers to trace the past patterns of human migration around the planet.
 
  • #35
excuse me!what is the definition of mutation and one more:as far as i know mutations cause diseases...has there ever been proved any beneficial mutation?if evolution choses the strongest why do we still have bacteria...if they got adopted why didn't they do that since the beginning. i don't believe the evolution theory,let me say the truth...too many gaps and too many "probably"...and all is based on mutation and statistics...well,the statistic doesn't prove this theory either as far as i have read...not even for a 100 piece protein...
in every evolution program i have seen they say "it trasformed..."gosh,every one knows that to use that word u include billion of operations inside...and when we talk about genetics we know that a single nucleotide mutation might be mortal...every one of u knows the frame shift mutations and their problems...and all of u know about cystic fibrosis and how it is caused...and a lot of other mutations...did u know that te splicing mecchanism cut the hnRNA of a Blc gene in 2 zones...one of them activates a gene for the apoptosis...the other is a protective one from apoptosis...and many other examples...and just a last question...has anyone of u seen any function inside the cell that seems useless?what about the bacteria or the other animals?they seem just perfect...too much perfect to say that they have been formed due to random mutations...these are the points that make me think that evolution isn't the right one to explain the biodiversity!

p.s:sorry for the mistakes i may have made becouse english is not my mother language!
 

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