Nitefly's Guide to Evolution

Arcade Fire · 3 Jul 2007 at 11:19

Nitefly said:
As far as our understanding has allowed and the model is concerned, it is 100% the end of the story or it wouldn't be a scientific theory. New evidence may allow us to improve our knowledge of evolution, or perhaps disprove it entirely!

I don't think that's true - if it were, the evolutionists would be out of a job! All scientific theories have problems which are yet to be overcome. Just look at general relativity and quantum mechanics (I'm choosing examples from physics because that's the field I'm most familiar with). We know that they're wrong, but that doesn't stop us using them. Rather than saying that evolution is 100% right, we should say that it's the 'most right' of all the theories we know.

A scientific theory should aim to make accurate predictions within its realm of applicability. It should not (and cannot) aim for absolute truth.

Nitefly · 3 Jul 2007 at 11:23

Arcade Fire said:
I don't think that's true - if it were, the evolutionists would be out of a job! All scientific theories have problems which are yet to be overcome. Just look at general relativity and quantum mechanics (I'm choosing examples from physics because that's the field I'm most familiar with). We know that they're wrong, but that doesn't stop us using them. Rather than saying that evolution is 100% right, we should say that it's the 'most right' of all the theories we know.

A scientific theory should aim to make accurate predictions within its realm of applicability. It should not (and cannot) aim for absolute truth.

Oh of course there is likely to be more discoveries to be made, my mistake in my misleading wording. I was merely stating that as far as we are aware, what is known about the model of evolution is 100% certain - to the extent of what we know. Your post is entirely correct

I told you I am not very good at wording such things

Duff-Man · 3 Jul 2007 at 11:24

Excellent post

It's good to see someone going to the effort of explaining a scientific subject properly.

A quick comment at Arcade Fire:

Quantum Mechanics and General Relativity are two (mutually incompatible) quantitative scientific theories. They describe *explicitly* the fundamental relationships that govern the universe we live in. They are (like Newtonian mechanics before them) merely approximations to a larger underlying principle. No physicist will argue with this.

However, evolution is not a quantitative scientific theory - it provides a qualitative explanation to the development we see around us. I take your point that it will always be an "incomplete" theory which will become better understoof with time, further experimental study (and most importantly in my view, large scale computer simulations of molecular and physiological evolution). However, comparing it to QM and GR is really comparing apples and oranges. They are about as far apart on the scientific scale as it is possible to be.

Nitefly · 3 Jul 2007 at 11:38

Duff-Man said:
Excellent post It's good to see someone going to the effort of explaining a scientific subject properly.

A quick comment at Arcade Fire:

Quantum Mechanics and General Relativity are two (mutually incompatible) quantitative scientific theories. They describe *explicitly* the fundamental relationships that govern the universe we live in. They are (like Newtonian mechanics before them) merely approximations to a larger underlying principle. No physicist will argue with this.

However, evolution is not a quantitative scientific theory - it provides a qualitative explanation to the development we see around us. I take your point that it will always be an "incomplete" theory which will become better understoof with time, further experimental study (and most importantly in my view, large scale computer simulations of molecular and physiological evolution). However, comparing it to QM and GR is really comparing apples and oranges. They are about as far apart on the scientific scale as it is possible to be.

Intriguing, thanks for your contributions, both of you

I will probably add something on this topic to the OP(s) in the next few days as clearly it is hard to word either what one is trying to say and pinpoint down this interesting point. I will consult my superiors and get back to you

p4radox · 3 Jul 2007 at 11:44

Absolutely fantastic post. 5* from me just for effort.

I'll read it later...

footman · 3 Jul 2007 at 12:01

A Magnum Opus !!
It will take all this evening to read it but I'm sure I'll learn a great deal...thanks

SteveOBHave · 3 Jul 2007 at 12:04

Nitefly said:
I told you I am not very good at wording such things

Well at least you don't come out with -"I think you're wrong and a dumbass to boot"

Trust me I'm flying the same flag and have a pretty in depth understanding of the Theory of Evolution and was likely as big a fan of dinosaurs as you were as a kid.

In no way am I trying to belittle your work - like I said in my last comment great stuff - but the greatest mistake we can possibly make as scientists/explorers/biologists etc is to say - "hey that's it - problem solved, theory complete". That's the point where we sit down and stop striving for knowledge - and if you ain't trying you're dying.

Duff-Man · 3 Jul 2007 at 12:07

Nitefly said:
Intriguing, thanks for your contributions, both of you

I will probably add something on this topic to the OP(s) in the next few days as clearly it is hard to word either what one is trying to say and pinpoint down this interesting point. I will consult my superiors and get back to you

I don't think what I wrote detracts in any way from your original post. I was just trying to highlight the difference between evolutionary theory and QM/GR. They're actually pretty interesting examples to compare and constrast, since they're effectively at opposite ends of the scientific spectrum.

For example: I can state explicitly that Schroedinger's equation is ******, or that the gravitational metric is ******. I can also say with certainty that these are good approximations to a larger underlying theory when applied in certain lengthscales and gravitational strengths (I can also say with equal certainty that they both fail when huge gravitational field strengths and small length scales coincide, such as close to black holes, but that's another matter entirely). The point is, I can use these quantitative relationships to predict with very high precision how a physical system will progress.

Evolution, on the other hand, is describing the development of a massively complex, nonlinear, chaotic system. We can use it to explain qualitatively how organisms evolved from simple bacteria to the creatures we see today. However, we cannot use it to predict the exact form a creature will take in the future. Even if we knew all the evolutionary pressures that would be placed on a species we would still not be able to accurately asses it's future evolution, any more than we could predict the final shape of a ********* from knowing the conditions in which it develops. This fact will not change, no matter how well developed evolutionary theory becomes.

Anyway my point is really that this isn't a failing of the theory, just an unavoidable consequence of dealing with chaotic systems. For the most part, theoretical physicists don't have to deal with this problem when constructing their theories

Nitefly · 3 Jul 2007 at 12:15

SteveOBHave said:
Well at least you don't come out with -"I think you're wrong and a dumbass to boot" Trust me I'm flying the same flag and have a pretty in depth understanding of the Theory of Evolution and was likely as big a fan of dinosaurs as you were as a kid.

In no way am I trying to belittle your work - like I said in my last comment great stuff - but the greatest mistake we can possibly make as scientists/explorers/biologists etc is to say - "hey that's it - problem solved, theory complete". That's the point where we sit down and stop striving for knowledge - and if you ain't trying you're dying.

That wasn't what I was trying to say at all, but I can very easily understand how it could have come across, my wording was very poor.

In the lab last week I was doing some fascinating work on molecular evidence. We visited Sand Bay (Near Weston-Super-Mare) and collected some plant samples and using their rDNA for sequencing we created our very own phylogenetic tree of our samples! Whilst this probably sounds a bit dull to non sciency types, it was incredible to actually take a living organism and see its DNA sequence on the computer infront of you! I still struggle to get my head around how much of an incredible piece of equipment modern DNA sequencers are (we had a megaBACE 1000).

My point is that the team is working to fine tune phylogenetic trees using molecular evidence. Many phylogenetic trees are incorrect or are misleading, and that fact that the same species are sometimes described twice with different names really doesn't help.

There is lots still for us to discover and understand in more detail in applied evolution

SteveOBHave · 3 Jul 2007 at 12:16

Duff-Man said:
Anyway my point is really that this isn't a failing of the theory, just an unavoidable consequence of dealing with chaotic systems. For the most part, theoretical physicists don't have to deal with this problem when constructing their theories

Indeed not. From what I understand the Theory of Evolution is designed to explain how we got here as opposed to where we are going.

Wouldn't it be intriguing to be actually able to postulate where human evolution is going (assuming we live long enough).

Nitefly · 3 Jul 2007 at 12:19

Duff-Man said:
I don't think what I wrote detracts in any way from your original post. I was just trying to highlight the difference between evolutionary theory and QM/GR. They're actually pretty interesting examples to compare and constrast, since they're effectively at opposite ends of the scientific spectrum.

Actually I was admiring you post, and this one was even better

I will be consulting my superiors about the content of these posts and I would like to add them to the OP(s) because I think it is very interesting and worthwhile knowledge.

Thank you

Duff-Man · 3 Jul 2007 at 12:21

A question for you if you don't mind, Nitefly...

What has been done in terms of studying the development of simple organic molecules into complex cellular structures? The reason I ask is everything I've read on evolution has always focussed in some way on the development of cellular organisms. I've never seen much on what happened to take 'primordial soup' to that stage

I've always been fond of the idea that the first bacteria arrived on our planet attached to a meteor giving us some kind of extra-terrestrial origin, although I'd be the first to admit this is pure fantasy and not based on anything concrete

Nitefly · 3 Jul 2007 at 12:25

SteveOBHave said:
Wouldn't it be intriguing to be actually able to postulate where human evolution is going (assuming we live long enough).

I would assume human evolution would be dependant on the lack of selection that is occuring, and the increasing rates of genetic drift that will be innevitable.

For example, people having glasses means eye sight is no longer selected for, whereas thousands of years ago, it may have been selected for due to increasing the hunting ability of an individual.

People who are limbless still have children, when in previous times before society probably will not have.

As such, humans will probably become a more vulnerable species. This is merely speculation, but it does lead to an interesting discussion

SunaseIPs · 3 Jul 2007 at 12:31

I actually wonder if women selecting men eg dark hair etc and darker skin is to do with global climate change and thus some evolutionary aspect? (maybe though I don't fully understand it all) of us is coming into play by selecting darker skin for our genes to survive as darker skin is stronger against the sun and its rays etc.

I probably am not making myself clear but I did try.

Nitefly · 3 Jul 2007 at 12:34

Duff-Man said:
What has been done in terms of studying the development of simple organic molecules into complex cellular structures? The reason I ask is everything I've read on evolution has always focussed in some way on the development of cellular organisms. I've never seen much on what happened to take 'primordial soup' to that stage

I've always been fond of the idea that the first bacteria arrived on our planet attached to a meteor giving us some kind of extra-terrestrial origin, although I'd be the first to admit this is pure fantasy and not based on anything concrete

No, there is evidence to suggest life might have arrived on the planet from an external source, but its far from conclusive and doesn't really prove anything. These topics are very briefly discussed at the very end of the OP(s), do a quick page search for 'Panspermia'.

As for how life evolved, we don't really know and can only form a hypothesis. Something which may interest you is the miller-urey experiment which created organic molecules from scratch, but this is highly controversial because it is believed it didn't represent the Earth's environment billions of years ago. Some content of this is found in OP(s), do a quick page search for 'oparin'.

Also, here is the Miller-Urey experiment in a little more detail.
Click!

If you want more info, my tutor is head of cell and developmental biology, so I could probably investigate for you

SteveOBHave · 3 Jul 2007 at 12:37

Nitefly said:
As such, humans will probably become a more vulnerable species. This is merely speculation, but it does lead to an interesting discussion

What about the possibility of the 'Stonger Better Faster' branching. As a race we are taller, certainly more physically developed than we used to be. Sooo we genetically dilute our senses with blindness and hearing difficulties but are gaining in size. Makes for a potentially interesting human doesn't it. Not forgetting that they'll all be red heads

SunaseIPs · 3 Jul 2007 at 12:41

SteveOBHave said:
What about the possibility of the 'Stonger Better Faster' branching. As a race we are taller, certainly more physically developed than we used to be. Sooo we genetically dilute our senses with blindness and hearing difficulties but are gaining in size. Makes for a potentially interesting human doesn't it. Not forgetting that they'll all be red heads

Humans are vulernable, we are more dependant on non natural methods to cure things, we can't slog it out. Ashthma, hayfever are physical signs of weakness I think.

While we create drugs to kill lurgies we make them stronger and our bodies weaker.

Oh and its the end of world soon, doom doom doom.

Nitefly · 3 Jul 2007 at 12:50

SunaseIPs said:
Humans are vulernable, we are more dependant on non natural methods to cure things, we can't slog it out.

Why?

Medical science is improving at an exponential rate. Still, it is impossible to speculate what the future will bring. A monster bird flue-esque virus which has antigenic variation (A method by which trypanosomes, a member of the protozoa, uses to avoid the immune system) could be the end of the human race.

Thankfully, the chance of that happening is completely unforseen and almost impossibly unlikely. But you never know

Combat squirrel · 3 Jul 2007 at 12:55

That dude is AWESOME ! THANKYOU !

-HOPEFULLY- people will understand better now ! 1st with honors !

Duff-Man · 3 Jul 2007 at 12:56

Nitefly said:
No, there is evidence to suggest life might have arrived on the planet from an external source, but its far from conclusive and doesn't really prove anything. These topics are very briefly discussed at the very end of the OP(s), do a quick page search for 'Panspermia'.

As for how life evolved, we don't really know and can only form a hypothesis. Something which may interest you is the miller-urey experiment which created organic molecules from scratch, but this is highly controversial because it is believed it didn't represent the Earth's environment billions of years ago. Some content of this is found in OP(s), do a quick page search for 'oparin'.

Also, here is the Miller-Urey experiment in a little more detail.
Click!

Oops, missed your final section

I suppose the 'panspermia' hypothesis allows a wider range of synthesis conditions than were present in primordial earth, perhaps increasing the probability of producing self-replicating organic molecules.

Thanks for the links

As for the human evolution issue: I've always thought that sentience and the formation of communities somehow 'breaks' evolution, removing the vast majority of traditional evolutionary pressures. However, in a way we now intelligently direct our own evolution - for example creating drugs to combat disease rather than waiting thousands of years for a natural immunity to develop through random processes.

In my eyes, the formation of sentience is kind of like a new plateu for evolution - I feel that we are 'evolving' much more rapidly than any previous species, albeit in a very different way.