Evolution — information increase and entropy

[artis]

Not sure whether this is the right category but bear with me.I've seen graphics where the information increase with time of evolution is projected like the one in the link below from Carl Sagan's book
https://www.researchgate.net/figure/Page-from-the-book-of-Carl-Sagan-21_fig2_322153131

Now I do understand this is a projection but apart from being a projection is there any real proof of this information increase ?
I understand that it is taken as proof when looked upon from the fact that humans for example have more neurons than chimpanzees.
But if we take any single species like humans or other mammals as an example, do we then have any evidence that within certain species the amount of information has increased with each following generation , like for example a human living 50 000 years ago might have X amount of total equivalent of information and we now have more?

I am asking this partly because unlike computers where we can interact and measure the amount of information stored in binary form in humans we could only theoretically measure the amount of heat produced by added information say in the lifetime of a human but as far as I know this heat is so small due to the efficiency of the brain that it is completely lost on the background heat of the organism so I suppose there is no way of determining any change in entropy of the organism when it is learning versus when it is not.

 

[russ_watters]

Now I do understand this is a projection but apart from being a projection is there any real proof of this information increase ?
I understand that it is taken as proof when looked upon from the fact that humans for example have more neurons than chimpanzees.

Yes, your answer is correct.

But if we take any single species like humans or other mammals as an example, do we then have any evidence that within certain species the amount of information has increased with each following generation , like for example a human living 50 000 years ago might have X amount of total equivalent of information and we now have more?

Probably a little, but that would be hard to measure unless we can measure, for example, changes in brain cavity size over time.

I am asking this partly because unlike computers where we can interact and measure the amount of information stored in binary form in humans we could only theoretically measure the amount of heat produced by added information say in the lifetime of a human but as far as I know this heat is so small due to the efficiency of the brain that it is completely lost on the background heat of the organism so I suppose there is no way of determining any change in entropy of the organism when it is learning versus when it is not.

I'm having trouble parsing what you are saying/asking here. A person is an open system -- like a jet engine (so is a computer). I'm not sure the idea "entropy of a person" makes any sense or what it would mean/what you could do with it. The only time I've heard the concept of entropy tied to evolution is for the common creationist misinformation claim that evolution contradicts the second law of thermodynamics. Could you clarify what your question/point is here?

 

[256bits]

But if we take any single species like humans or other mammals as an example, do we then have any evidence that within certain species the amount of information has increased with each following generation , like for example a human living 50 000 years ago might have X amount of total equivalent of information and we now have more?

there are two types of biological information storage
1. that within the genetic code of the organism, which is the solid line curve in the diagram.
those organism with more DNA in the nucleotide have more of this information and the curve roughly follows along with more or less from virus to human
2. that which can be stored in the biological memory of the organism, which would be storage in the nervous system, including the brain. Organisms with a larger brain should have more of this potential information storage available to them.

A comparison two humans from different time periods is not reflected in the graph. They are both humans, and the extrapolation between generations of individuals is unjustified.

 

[artis]

@256bits can you please elaborate of which particular extrapolation being unjustified you meant?

@russ_watters well I was thinking along the lines of if we could measure the information increase in the life of a human we could then approximately measure the amount of information handed over by the dna and the amount of newly created information during a persons lifetime, if we could say somehow measure the information increase for a person during a certain task which the person learns from zero. Much like we can measure the amount of "learned" information for a neural network learning to play chess from scratch.As for evolution here I have a question, so when we compare the neurons between different species we see a difference, but in terms of the genetic information encoded within our DNA , have there been any clear evidence that a human tose same 50k years ago had say less neurons or less genetic encoded information than ones living today?
My point here is this that depending on the answer to this question I could argue that the total increase in knowledge is simply due to the fact that more and more knowledge is stored in books, hard drives etc and more and more people are born which can use that already processed and stored knowledge but that this does not necessarily mean that the modern human is somehow more capable intellectually on average than a human who lived many k years ago.

PS. my reasoning has nothing to do with creationism I'm just trying to understand this subject and define some concepts.

 

[256bits]

@256bits can you please elaborate of which particular extrapolation being unjustified you meant?

As for evolution here I have a question, so when we compare the neurons between different species we see a difference, but in terms of the genetic information encoded within our DNA , have there been any clear evidence that a human tose same 50k years ago had say less neurons or less genetic encoded information than ones living today?

Are you asking about the different sub-species of humans, which would have had different genetic encoding and different neurological capacity? where would those points lie on the graph? The human species to which you and I belong is Homo Sapiens Sapiens, as far as I know is the only member of the genus living today. A Homo sapiens sapiens living 50,00 years ago is 'assumed' to of the same type, otherwise they would be classified differently. The phenotype is the outwards observable traits of the individual. Contributions come from the genotype and environmental factors. Call me out if incorrect but a human 50000 years ago would have basically the same genotype as one today.

Having said that, 'about 2 percent of the DNA in the genomes of modern-day people with Eurasian ancestry is Neanderthal in origin', and quite possibly some Neanderthral DNA does exist in humans in other continenents.
https://www.the-scientist.com/features/neanderthal-dna-in-modern-human-genomes-is-not-silent-66299
Whether that has shifted the featured graph slightly to the left or the right for the point called humans if there had not been any Neanderthral DNA infusion is indeterminate.

 

[artis]

Well to make a long story short my friend is working on a information theory approach to evolution, he is retired and has free time on his hands, he told me about it and I was intrigued.

The idea here is rather simple, apart from the "missing links" or the clear examples of transformational fossils there is one other way to approach evolution and that is to see how the amount of information has changed within each species over the years. Now since humans are the most developed and complex species in terms of how much information we operate with , we also have the most neurons of any species.
The question is whether we always had such a number of neurons while we were the same species as we currently are?

It would be interesting to know whether there is any possible method even in theory by which once could estimate the amount of information passed on to each next generation to understand whether the total amount of encoded information is increasing or not.
In the absence of better proof to me it now seems that there is no clear way to determine the amount of increase/decrease of information within an organism and it's species both biological/genetic information and acquired information which is learned within one organisms life and then passed on as a talent to the offspring or otherwise.

correct me if I'm wrong

 

[DrStupid]

But if we take any single species like humans or other mammals as an example, do we then have any evidence that within certain species the amount of information has increased with each following generation , like for example a human living 50 000 years ago might have X amount of total equivalent of information and we now have more?

Evolution maximizes the fitness of the species and I do not see a reason for a strong correlation between fitness and the amount of information. Thus I do not expect a general increase of the amount of information for every single species. In some cases it might be the other way around, e.g. by specialization into an ecological niche.

 

[A.T.]

Evolution maximizes the fitness of the species and I do not see a reason for a strong correlation between fitness and the amount of information.

As far as I know (not a geneticist) not all of the information stored in the DNA is actively used, and it's also not optimized to storage capacity. So the first hurdle would be to define/quantify the amount of information.

 

[DrStupid]

As far as I know (not a geneticist) not all of the information stored in the DNA is actively used, and it's also not optimized to storage capacity.

Information that is not required can get lost without consequences other than saving energy (because it doesn't need to be replicated anymore). That doesn't result in an optimization to storagage capacity because there is also new junk RNA produced. But there is at least no uncontrolled grow of useless information. In the long term I would expect some kind of steady state with a stable amount of trash.

So the first hurdle would be to define/quantify the amount of information.

The total length of the DNA should be a good indicator. Another possibility is the length of the coding DNA. The diversity of DNA within a species should also be considered.

 

[artis]

So basically apart from the average neuron count difference between species the only other way by which one could interpret the increase in information stored/complexity is by studying the DNA of a certain species to see the difference , say for example taking a fossil from a human that lived 100k years ago versus one that died recently?Because we cannot see changes in real time both due to their tiny amount and also because of measurement errors so we can see them through DNA over longer periods of time and then extrapolate?
I wonder about one thing , since DNA analysis is a very recent field , how did we find scientific proof for evolution within given species before that? Was it solely down to studying the culture artefacts found nearby the fossil and by visual comparison of the fossil with other known fossils in order to spot certain differences and then determine that change had happened?
If what I say is right , seems like without DNA determination of evolutionary change within one species is rather crude, aka down to secondary evidence like approximate age of fossil vs how it compares to other fossils vs in what Earth layer and place it was found?

 

[anorlunda]

I wonder about one thing , since DNA analysis is a very recent field , how did we find scientific proof for evolution within given species before that?

https://en.wikipedia.org/wiki/On_the_Origin_of_Species

 

[russ_watters]

So basically apart from the average neuron count difference between species the only other way by which one could interpret the increase in information stored/complexity is by studying the DNA of a certain species to see the difference , say for example taking a fossil from a human that lived 100k years ago versus one that died recently?Because we cannot see changes in real time both due to their tiny amount and also because of measurement errors so we can see them through DNA over longer periods of time and then extrapolate?

It seems like you are mixing together two different things. Information we learn (memories) is not stored in our DNA.

I wonder about one thing , since DNA analysis is a very recent field , how did we find scientific proof for evolution within given species before that? Was it solely down to studying the culture artefacts found nearby the fossil and by visual comparison of the fossil with other known fossils in order to spot certain differences and then determine that change had happened?

Evolution isn't about culture, nor is culture stored in DNA, so I'm not sure what you are asking. Evolution is tracked back in time by examining the remains of organisms. Period. That may include ancient DNA that is recovered from well preserved remains.

If what I say is right , seems like without DNA determination of evolutionary change within one species is rather crude, aka down to secondary evidence like approximate age of fossil vs how it compares to other fossils vs in what Earth layer and place it was found?

I'm not sure if "crude" is the right word for it, but the more you zoom in on a timeline, the more granular/noisy the view gets.

Human evolution:
https://en.wikipedia.org/wiki/Human_evolution

 

[artis]

@russ_watters no I am not implying, although it might seem so, that our lifelong memories are part of the information that gets coded into our DNA.
That being said some forms of information that we gather throughout our life have to pass down through genes over many many generations, don't they?
I mean if we shared a common ancestor with apes then there is a reason why we don't walk like apes I suppose and this change in our physical appearance and the way we move came about gradually so new information was added eventually to the DNA.

@anorlunda I have read those entries before , but going over them just tells me what I think I know already that basically Darwin founded his theory mostly on belief and appearance because back in his day we did not have radiocarbon dating nor we had any understanding of DNA. I think the most sophisticated instrument we had back then was the optical microscope. So he had to rely on a lot of observation and interpretation.
This is somewhat what I was reflecting in my previous entry @russ_watters , I do agree I mixed the phrase culture in there and that was wrong.

 

[russ_watters]

That being said some forms of information that we gather throughout our life have to pass down through genes over many many generations, don't they?

No, how/why would it? What sort of information are you thinking, and how would it be "pass[ed] down through genes" if not encoded into DNA?

I mean if we shared a common ancestor with apes then there is a reason why we don't walk like apes I suppose and this change in our physical appearance and the way we move came about gradually so new information was added eventually to the DNA.

Does a distinction between "new" and "different" matter here?

Human genetic evolution:
https://en.m.wikipedia.org/wiki/Hum...ow,and forensic implications and applications.

 

[artis]

@russ_watters hmm ok, well I'll admit I'm partly confused myself here so let me ask a question,

I was thinking say examples like talents etc.
Very often children in families where their parents have been musicians they pick up music from an early age, sure one can say it's environmental but let's be honest here without musical hearing and other traits it's almost impossible to do.
Then there are the extreme examples like Mocart who basically learned to write and play operas before he learned to run etc, I don't think something like that can be environmental given at how early an age the prodigy achieves such a level.

But talking about things like our posture and body size etc those definitely I think are coded into the DNA so they must have come about gradually , the question then is how? Did they come about as random changes throughout generations of ancient humans or did they come about as lifestyle adaptations or both ?

I have the feeling that DNA research can tell the basics about how DNA programs certain body functions and parts down to hair color but can't exactly tell the more subtle details like what sort of predisposition for what talent etc one might have is that true?

One thing is clear i have to read about this a lot more.

 

[DrStupid]

What sort of information are you thinking, and how would it be "pass[ed] down through genes" if not encoded into DNA?

Information gathered throughout our life can be passed down through genes over many generations by DNA methylation. It might not be the information that artis is thinking about but it has been confirmed by animal experiments.

 

[artis]

Ok so let me then ask, do we have the capability already to be able to take dns samples from same species individuals that have lived with some time difference , say 10k years and determine based on their genetic information the differences that have happened between those samples which would amount to the change of genetic information in that species over the said 10k period?

 

[jbriggs444]

Ok so let me then ask, do we have the capability already to be able to take dns samples

Unfortunately not. It appears that the marketeers got there first...

Non-authoritative answer:
Name: elk.com
Address: 69.172.201.208

> set type=soa
> elk.com
Non-authoritative answer:
elk.com
primary name server = ns1.uniregistrymarket.link
responsible mail addr = hostmaster.hostingnet.com
serial = 1555555555
refresh = 10800 (3 hours)
retry = 3600 (1 hour)
expire = 604800 (7 days)
default TTL = 86400 (1 day)

[On the plus side, one could easily come up with some objective measures for the information content of a DNS zone file and track its evolution over time]

 

[artis]

well nice pun right there @jbriggs444 I made a mistake since DNS is how I say it in my native language but DNA would have been the right choice.
So is there still an answer to my question then?

 

[jbriggs444]

well nice pun right there @jbriggs444 I made a mistake since DNS is how I say it in my native language but DNA would have been the right choice.
So is there still an answer to my question then?

Short answer is "I do not know".

However, I am skeptical that we can find enough ancient DNA to analyze. Skeptical that the DNA will be complete enough to determine the total DNA length. Skeptical that total DNA length is good proxy for species genetic information content. Skeptical that the sample size is enough to allow a conclusion to be drawn. And skeptical about the truth of the thesis that genetic information content must increase over time.

 

[artis]

@jbriggs444 ok but if that information content does not increase then how does evolution happen in the first place?
I suppose that humans did not get more neurons in their brains by accident as compared to chimpanzees but rather there was a change gradual supposedly over time in the genetic code that led to the real physical changes in the body?

 

[jbriggs444]

@jbriggs444 ok but if that information content does not increase then how does evolution happen in the first place?
I suppose that humans did not get more neurons in their brains by accident as compared to chimpanzees but rather there was a change gradual supposedly over time in the genetic code that led to the real physical changes in the body?

The fact that an organism is more fit for a purpose does not require that the organism be more complex. [Though it is definitely the easy path forward -- layering additional complexity on top rather than going for a re-design].

 

[DrStupid]

I suppose that humans did not get more neurons in their brains by accident as compared to chimpanzees

No they don't and domestic cats didn't got less neurons in their brains by accident as compared to wild cats. As already mentioned above, evolution maximizes fittness but not necessarily complexity.

 

[sophiecentaur]

It seems like you are mixing together two different things. Information we learn (memories) is not stored in our DNA.

Perhaps there's more to it than that.
The theories of Lamarckism were discredited largely, at the time of the rise of Darwinism. But there are now suggestions that it may have been dismissed prematurely. Mendalism may not explain it all. There is far more information on our genome than has actually be tabulated and associated with all characteristics. Lamarckism is one of those things that cannot be 'disproved'; it can only be 'unconfirmed'. It doesn't actually compete with conventional genetics and it could be a viable idea that the (male) gamete could be modified during the life of an individual. The female gamete couldn't be modified during the life of the mother (eggs already formed in the embryo) but a generational delay would be possible.
I'm only reporting what I've heard on radio broadcasts and I have no references. Metagenetics is a big field of study these days and provides a link between living conditions and characteristics in later generations.

 

[Drakkith]

ok but if that information content does not increase then how does evolution happen in the first place?

Evolution is, in general, a change in a population of organisms over time. That change does not have to be the result of additional 'information'. For example, the deletion and subsequent loss of a gene that is vital to eyesight is not detrimental to a spider species that lives solely in dark caves where there is no light. Hence why we commonly find blind animals inside of dark caves. The loss of their eyesight is still evolution.

I suppose that humans did not get more neurons in their brains by accident as compared to chimpanzees but rather there was a change gradual supposedly over time in the genetic code that led to the real physical changes in the body?

It was both accidental and not accidental. The mutations in the DNA were accidental, but natural selection is not. Given some change in a population of organisms or a change in their environment, natural selection will tend to drive that population to be better fit in their environment. But natural selection has to work with what the random mutations give the population. If a population of blind spiders experience a cave-in that exposes them to the outside, natural selection can't select for better eyesight until the mutations in their DNA let it (either by a mutation undoing a previous mutation or by mutating an entirely new gene that replaces the function of the old one).

One way for a species to go extinct is for it to fail to acquire the mutations to sufficiently adapt to its environment and outcompete (or at least keep up with) predation and competition.

 

[Drakkith]

I have the feeling that DNA research can tell the basics about how DNA programs certain body functions and parts down to hair color but can't exactly tell the more subtle details like what sort of predisposition for what talent etc one might have is that true?

That's the status of things now, but we'll have to wait to see what the future holds. Generally, the more complex something is, the longer it takes to understand fully. And the human body is extraordinarily complex. The development of the human body involves thousands of different proteins and other molecules, each interacting with each other in different ways, and the genes that control growth and development are numerous and interact with each other, along with other genes, in different ways at different times and at different strengths.

Not only that, but genes that control something in one cell type can contribute to something entirely different in another cell type or even something different in the same cell type at different life stages. Or a cell can use a single gene in multiple ways via different signaling pathways or structural components. Heck, two different people with the same mutation in the same gene can sometimes experience totally different things because of it. That's why genetic diseases often present with a range of symptoms that varies from person to person.

The human body is staggeringly complex, and understanding it fully won't happen for a very long time.

 

[sophiecentaur]

The human body is staggeringly complex, and understanding it fully won't happen for a very long time.

I guess there's an argument that our comprehension of the process may be limited by our finite brain size (or even combined brain size). It's the same old problem of making a map of an area which has to include the map itself, which includes a map of a map, and a map of the map of the map - so on to infinitum.

How natural is the 'natural' in 'natural selection'? Trying to associate the entropy of life with conventional thermodynamic entropy is very problematical. Perhaps there is no paradox if the 'laws' about entropy are just not relevant in some circumstances. After all, it's only Maths and self-consistent Maths doesn't always deliver relevant answers.

 

[artis]

@jbriggs444 I am not implying that a better suited or more fit organism has to be more complex nevertheless a change in the organism is represented by change in genetic information which is what I'm after.

the same goes to @DrStupid , I sure get what you say but still the change in genetic material across multiple generations must be there even if we cannot "read it" now or ever?@Drakkith I get what your saying , no doubt there have been/are cases where a decrease in information has happened although if we look at the whole picture from the first cell that supposedly assembled itself long long ago to the "king of the modern jungle" aka human then we can no doubt say that genetic information has mostly increased in size and complexity, I'd say the general trend of evolution is to or have been to make more complex organisms/add information.

@sophiecentaur well I'm not implying thermodynamic entropy as such although whenever using our brain to learn something (which doesn't necessarily get's passed down but is of the environmental type of information) there is entropy involved because the addition of information results in real physical heat generated/energy expended although so small one can't measure it.
All in all I suppose also based on this discussion that the idea of the genetic information is very reasonable and maybe someday we will be able to really see the evolutionary timesteps because with only fossils and their dating the picture is not very complete.

 

[artis]

Given some change in a population of organisms or a change in their environment, natural selection will tend to drive that population to be better fit in their environment. But natural selection has to work with what the random mutations give the population.

Well I sort of knew this but from you saying it I sort of want to ask,
How come then evolution had the chance to move forward at all and produce so many different species, because sure natural selection selects the better fit species/individuals, sure that is simple but natural selection can only work with random mutations which is nicely put by you so if we go back to the early days of primitive organisms, of all the possible random mutations that could have happened what is the chance that just the right mutations came along in order for the species to survive?

Sure enough once you produce something as complicated as homo sapiens you are well off because as we can see our intellect has helped us build stuff in order to survive but much before this when you only got a primitive bunch of organisms I'd noramlly think their chances of survival in an unaided primitive environment are rather slim.
+ the mutations are not fast enough or should I say slow, so besides the slim chance of getting the right mutation one also has to wait a long time for it.

It would almost seem to me that evolution becomes problematic at the very start and soon after, along the way it;'s easy to apply the natural selection and mutation rules but at the very beginning is where I personally feel like we are not seeing the whole picture, how certain are with the the early facts ?

 

[Drakkith]

How come then evolution had the chance to move forward at all and produce so many different species, because sure natural selection selects the better fit species/individuals, sure that is simple but natural selection can only work with random mutations which is nicely put by you so if we go back to the early days of primitive organisms, of all the possible random mutations that could have happened what is the chance that just the right mutations came along in order for the species to survive?

Remember that every single time an organism reproduces it introduces a chance of a mutation, so there are a lot of chances and a lot of mutations that occur over time. The deleterious ones are selected against, and even if they make up 99% of the mutations (they don't, as neutral mutations are more common) they don't spread throughout the population very easily and are thus easily lost by a population.

Beneficial mutations, on the other hand, are selected for, and once one happens it is far more likely to spread throughout a population over time than a deleterious one (in general, as there are complicating factors here).

Also remember that there isn't likely to be just a single possible beneficial mutation for a given population in a given environment, there are many. And the number of possibilities for either type tends to increase as organisms get more complex, as there are more things to change in a complex organism.

Sure enough once you produce something as complicated as homo sapiens you are well off because as we can see our intellect has helped us build stuff in order to survive but much before this when you only got a primitive bunch of organisms I'd noramlly think their chances of survival in an unaided primitive environment are rather slim.

Well, you're right in the sense that survival rates are much, much higher now for us than they were 50,000+ years ago. But just look at the other great apes. They don't build complicated structures or tools, yet they survive just fine in their environment. Our key evolutionary advantage is our intellect, which has allowed us to overcome the limitations that evolution has placed on our bodies by letting make clothes, shelter, fire, grow food, etc.

+ the mutations are not fast enough or should I say slow, so besides the slim chance of getting the right mutation one also has to wait a long time for it.

Certainly. That's why evolution generally takes millions of years to substantially change a population of organisms.

One thing you might not be considering is that the very way we are built makes it actually quite easy for small changes in DNA to lead to large changes in form or function. Complex organisms are quite modular in the sense that they use a small number of building blocks to build up larger pieces, and these pieces are used to build larger components, which are used to build cells or to signal things. A mutation doesn't need to change the basic building block (and mutations which do so are often lethal), instead it can change the way these blocks or components are arranged, the order they are assembled, or the number of blocks or components used, which can result in substantial large-scale changes without much change in the basic blocks or components.

For example, a mutation in the regulatory region of DNA for the Antp Hox gene in flies can 'turn on' this gene in the head of a developing fly, converting its antennae into legs instead. The fly will literally have legs coming out of its head.

Similar mutations can occur in crustaceans, turning various appendages into different ones, and explaining how many closely related species can have very different types of appendages at the same points of their bodies.

It would almost seem to me that evolution becomes problematic at the very start and soon after, along the way it;'s easy to apply the natural selection and mutation rules but at the very beginning is where I personally feel like we are not seeing the whole picture, how certain are with the the early facts ?

Evolution worked on the precursors to cells just like it works on us now. The different types of molecules and protocells were selected for or against by virtue of how well they were able to survive and replicate. Instead of mutations in DNA, the 'mutations' would have initially been in the physical shape or the chemical makeup of the molecules, and as things grew more complex would have shifted over to DNA/RNA or their possible precursors.

Again, remember that even though the chances of something 'beneficial' happening at this stage is quite low, the huge numbers of these precursor molecules in the oceans and the vast time scales give an enormous number of chances for a beneficial mutation to occur.