Historical Record Indicates a Significant Acceleration of Evolution

[dr.syntax]

The evolution of life on Earth of the simpler to the more comlplex organisms. A look at the timeline of evolution is a good place to start. A very good one is available at: http://www.absoluteastronomy.com/topics/Timeline_of_evolution .We can see from this timeline that life began with the prokaryotes 3.8 billion years ago.From then it took another 1.8 billion years to evolve the simplest eukaryotes. From then another 1 billion years before the simplest multi-cellular organisms. The first fish and proto-amphibians .5 billion years later. From then another .14 billion years for true amphibians to emerge. Reptiles appear .6 billion years later.Mammals emerge .1 billion yars later. The genus homo appears .002.5 billion years later. Humans looking very much as they do today appear on the scene .0003 billion years ago. That web link I provided gives a much more detailed breakdown of the historical record along with a lot of ineresting things about the different aspects of evolution. It`s worth mentioning that many of those earlier lifeforms are still with us today. Those prokaryotes for example. Some forms of them live in your intestines and are required for the digestion of food. There are many other examples including fungi, clams,snails,sharks,all coniferous trees,and many others. The reasons for this acceleration of evolution through time is that any attribute for an organism to more rapidly change in a way that aids in it`s survival will be selected for by natural selection. The most striking examples I can think of are sexual reproduction and the intra-species competition for mating rights. It is important to note that during that long 1.8 billion years of exclusively prokaryotic life, these prokaryotes developed the ability to exchange genetic information. One of the principles I am try to illustrate is that it was the gradual accumulation over time of traits amongst the different organisms that caused this acceleration of evolution.Bacteria evolved mechanisms for exchanging partial genetic information. The three known methods are 1. transformation 2. transduction 3. conjugation . This is not sexual reproduction. For more on this go to: http://www.britannica.com/EBchecked/topic/48203/bacterial/272363/exchange_of_genetic_information . Upon further reflection it appears to me that it is likely that the ability to exchange genetic information in a progressively more efficient manner is the basis for the acceleration of biologic evolution: from the simpler to the more complex. Even intra-species competetition for mating rights is a means of refining the process of genetic information exchange. It promotes the genetic information of the most fit and able within a paticular species. Not wasting evolutionary time on the less fit and degrading the gene pool with undesirable characteristics. This may seem cruel and uncaring to some people. It does to me. But that is the way evolution works. If it were not for the total indifference of evolution to the survival of any particular individual organism , or species the process would not work and we people along all the other species would not exist. ...Dr.Syntax

Edited September 24, 2009 by dr.syntax
mispellig,addition

[Mokele]

Learn to use paragraph breaks.

[Skye]

Or you could argue that evolution is slowing down. During the first two billion years three domains emerged, during the next two billion years no new domains emerged. It depends on which pretty arbitrary metric you use.

[Mr Skeptic]

May I suggest as the measure, the total amount of genetic information. By information I mean the sort of measure used by information theory, where two identical copies don't count as double the information of the first. Think the amount of data after applying a perfect compression algorithm.

[dr.syntax]

Or you could argue that evolution is slowing down. During the first two billion years three domains emerged, during the next two billion years no new domains emerged. It depends on which pretty arbitrary metric you use.

 

In my opening statement I said " The evolution of life on Earth of the simpler to the more complex organisms." The numbers of domains is not what I am trying to discuss. My intention is to explain how the process of simpler organisms have evolved into more complex organisms at an accelerating rate.The fact that archea emerged along with bacteria in the primorial oceans is not surprising. I have a question for you. Did all eukaryotes that are alive today evolve from bacteria ? ...Dr.Syntax

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May I suggest as the measure, the total amount of genetic information. By information I mean the sort of measure used by information theory, where two identical copies don't count as double the information of the first. Think the amount of data after applying a perfect compression algorithm.

 

The means by wich the simpler organisms are evolving into more complex organisms at an accelerating rate. The total amount of genetic information out there is not what I am concerned with and may often conflict with the overall complexity of the organisms. For example: those primorial oceans may or may not have contained a larger total amount of different genetic information. As time goes by natural selection decides just what genetic information is useful in sustaining the different life forms. And that most of what was out there was selected against for one reason or another. Just so much useless or even harmful crap that needs to be deleted from the overall gene pool. ...Dr.Syntax

[Skye]

In my opening statement I said " The evolution of life on Earth of the simpler to the more complex organisms." The numbers of domains is not what I am trying to discuss. My intention is to explain how the process of simpler organisms have evolved into more complex organisms at an accelerating rate.

The problem then is, what is complex?

 

You're assuming that we are complex, and in many ways we are, but in other we are simple. Metabolically, like I said in that other thread, for example. So you have to specify what you mean by complex. Is it the structure of the cell? Multi-cellular life? Behaviour? Senses?

 

As far as a mechanism of how complexity emerges, this has been studied and thought about a great deal. Stephen Jay Gould was good at explaining this sort of thing, here's an interview with him on the subject giving his view:

 

http://www.pbs.org/newshour/bb/science/gould_11-26.html

The fact that archea emerged along with bacteria in the primorial oceans is not surprising. I have a question for you. Did all eukaryotes that are alive today evolve from bacteria ? ...Dr.Syntax

Eukaryotes have features of both archaea (nuclear chromosomes) and the prokarya (cell membrane and plasmids, like mitochondria and chloroplasts). So there must have been some degree of mixed parentage, such as fusion, symbiosis or a sort of failed attempt to engulf and digest another cell. Also, genetic elements from viruses are common in the genomes of eukaryotes.

[dr.syntax]

The problem then is, what is complex?

 

You're assuming that we are complex, and in many ways we are, but in other we are simple. Metabolically, like I said in that other thread, for example. So you have to specify what you mean by complex. Is it the structure of the cell? Multi-cellular life? Behaviour? Senses?

 

As far as a mechanism of how complexity emerges, this has been studied and thought about a great deal. Stephen Jay Gould was good at explaining this sort of thing, here's an interview with him on the subject giving his view:

 

http://www.pbs.org/newshour/bb/science/gould_11-26.html

 

Eukaryotes have features of both archaea (nuclear chromosomes) and the prokarya (cell membrane and plasmids, like mitochondria and chloroplasts). So there must have been some degree of mixed parentage, such as fusion, symbiosis or a sort of failed attempt to engulf and digest another cell. Also, genetic elements from viruses are common in the genomes of eukaryotes.

 

I appreciate your informative answer to my question very much. The best definition I can come up with as to what it is about an organism I consider defining as a stardard to measure relative complexities by would be the: anatomical complexity of the nervous system and especially the brain. Such considerations as the size and complexity of the neocortex in particular. Most if not all of the lower structures are shared by at the very least all mammals. Nevertheless many of event these lower structures grow in size and complexity in the more highly evolved mammals. I do not assume we human beings are at the top of this list. Some porposes,whales, and elephants have comparatively equal or more complex and developed neocortexes. ...Dr.Syntax

Edited September 24, 2009 by dr.syntax
spelling

[Mokele]

That's a completely arbitrary and useless metric. Why not use the complexity of the musculo-skeletal system and locomotion? After all, all animals have that, and all lifeforms move (actively, passively, or by differential growth)? Or why not the complexity of the endocrine system?

 

Your post shows a high degree of "Scala Naturae" thinking, with humans at the top of the evolutionary ladder.

 

Now, there is a grain of truth - from time to time, "key innovations" pop up, allowing rapid diversification, such as multicelluar forms, the complex jaws of fish, insect flight, the plant vascular system, etc. But these are essentially randomly scattered through time, and also prone to being arbitrarily defined.

[Sisyphus]

Human genome: 2.9 billion base pairs.

Amoeba dubia genome: 670 billion base pairs.

 

Just thought I'd toss that in the mix.

[Ophiolite]

That's a completely arbitrary and useless metric. .

I'm not sure that I would call it useless - it may have some limited specific use - but it is certainly arbitary. Other metrics would show no change in pace of evolution, or fluctuating paces, or slowing down. The end result is meaningless. It might be interesting to see it applied in a systematic and quantitative manner alongside other metrics, but by itself it offers nothing new.

[Mr Skeptic]

The total amount of genetic information out there is not what I am concerned with and may often conflict with the overall complexity of the organisms. ... Just so much useless or even harmful crap that needs to be deleted from the overall gene pool.

 

I understand, but I simply suggested it as a clear, easy metric.

 

The best definition I can come up with as to what it is about an organism I consider defining as a stardard to measure relative complexities by would be the: anatomical complexity of the nervous system and especially the brain. Such considerations as the size and complexity of the neocortex in particular.

 

Isn't this extremely arbitrary though? There really is no reason nerves had to evolve, nor a brain, nor in particular the neocortex. Some organisms have none of these, so your metric would be useless to them. A more accurate metric than the one I suggested would consider the efficiency of various physiological processes, or adaptability, for example. These are less arbitrary and more widely applicable than just focusing on the nervous system.

[CharonY]

May I suggest as the measure, the total amount of genetic information.

 

While it may sound logical, it has several issues. One of them being that during evolution information can be gained as well as lost. As such it will be tricky to impossible to use that metric. Also, horizontal gene transfer is the single most effective way to gain large chunks of genetic information within and between species (and makes a big mess out of phylogenetic analyzes). This is incidentally also an argument against the assumption that higher multicellular eukaryotes may have a more efficient way of exchanging genetic information.

 

Edit: shouldn't this be in speculations?

Edited September 24, 2009 by CharonY

[bascule]

While it may sound logical, it has several issues. One of them being that during evolution information can be gained as well as lost. As such it will be tricky to impossible to use that metric. Also, horizontal gene transfer is the single most effective way to gain large chunks of genetic information within and between species (and makes a big mess out of phylogenetic analyzes). This is incidentally also an argument against the assumption that higher multicellular eukaryotes may have a more efficient way of exchanging genetic information.

 

Edit: shouldn't this be in speculations?

 

What if you included the total information included in a species' "extended" phenotype?

[CharonY]

If you mean it as Dawkins described it, it would not change much, would it? Gene loss is gene loss. Or am I misunderstanding you?

[Mokele]

Forget gene loss, what about polyploidy? Whole genome duplications aren't as rare as folks think - within genus Xenopus (clawed frogs, a common model species for endocrine and developmental work) there are individuals with 2N, 4N, 8N, and 12N chromosomes.

 

Is X. ruwenzoriensis really 6 times as advanced as the superficially identical X. tropicalis?

[CharonY]

Good point, but wouldn't it be under Skeptic's definition just count as zero change? Though of course polyploidy obviously does have effects, which in turn might be another argument against this as a metric.

But just to get back on track, a common metric to clock evolutionary changes is based on phylogenetic analyzes of certain genes and/or proteins. The precise intention of the analyzes defines the choice of suitable sets (e.g. whether one uses more or less conserved ones that is). My personal opinion is that in the near to mid-future there will be a switch to using whole genome information. Though the feasibility has to established first. Nonetheless a complete phylogenomic approach would take e.g. synteny as well as gene duplications better into account than other approaches. Also horizontal gene transfer could have a lower effect on the results as their influence may be diminished due to the influence of the remaining markers. Downsides are, among others, computational costs as well as properly anchoring the sequence in less related organisms. I do have seen a few papers addressing these issues, though.

[dr.syntax]

That's a completely arbitrary and useless metric. Why not use the complexity of the musculo-skeletal system and locomotion? After all, all animals have that, and all lifeforms move (actively, passively, or by differential growth)? Or why not the complexity of the endocrine system?

 

Your post shows a high degree of "Scala Naturae" thinking, with humans at the top of the evolutionary ladder.

 

Now, there is a grain of truth - from time to time, "key innovations" pop up, allowing rapid diversification, such as multicelluar forms, the complex jaws of fish, insect flight, the plant vascular system, etc. But these are essentially randomly scattered through time, and also prone to being arbitrarily defined.

 

REPLY: and I never said humans were at the top of this scale. Quite the contrary: I said " some porposes,whales, and elephants have comparatively equal or more developed neo-cortexes. There is nothing arbitrary about my choice of the complexity of the neo-cortex as the standard I chose to define what is the most complex. It is the latest of all the organs to have evolved in any large animal group and I consider it a very good choice. ...Dr.Syntax

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Human genome: 2.9 billion base pairs.

Amoeba dubia genome: 670 billion base pairs.

 

Just thought I'd toss that in the mix.

 

Sisyphus brought this up and I looked into and he is right. An onion has 12 times as much and a rasberry has 8% as much. It all seems very strange and unexpected ,by me any way. A short fun article about all this is at : http://www.news.harvard.edu/gazette/2000/02.10/onion.html . I would think that these facts would rule out any system of an rating an organism`s complexity based on the amount of genetic information it carried about a bit preposterous and unworkable. Some of the simpler organisms do have less DNA than we do. The fruitfly is another example that appears to be particularily effecient at deleting useless DNA compared to most orgaisms. I don`t know what to make of all that. It is not the amount of DNA any particular organisms carries about, but the amount of useful survival promoting DNA that becomes expressed as usefull traits that matters. Evidently some of the simplest organisms carry vast amounts of useless DNA about. I guess they did not develope an effecient delete function for junk DNA. And it is not always the simpler that have more DNA. Those rasberrys have 8% of the DNA of humans the onions 12 times as much as a human being. Oh well, ...Dr.Syntax

Edited September 26, 2009 by dr.syntax
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[Mokele]

REPLY: and I never said humans were at the top of this scale. Quite the contrary: I said " some porposes,whales, and elephants have comparatively equal or more developed neo-cortexes. There is nothing arbitrary about my choice of the complexity of the neo-cortex as the standard I chose to define what is the most complex. It is the latest of all the organs to have evolved in any animal and I consider it a very good choice. ...Dr.Syntax

 

Wrong. The neocortex is present in all mammals, therefore at least 150 million years old, possibly as old as 200 million years. This predates the entire snake adaptive radiation, flowering plants, eusocial insects, bird flight, echlocation in any form, and modern coral reefs.

 

By your logic, since snake venom glands evolved *after* the neocortex, they're a better metric of evolutionary rate. Or the ability to flower.

 

Can you give any scientific reason for using the nervous system as a metric rather than, say, the digestive system, or the muscular system? All are essential to life.

[dr.syntax]

I understand, but I simply suggested it as a clear, easy metric.

 

 

 

Isn't this extremely arbitrary though? There really is no reason nerves had to evolve, nor a brain, nor in particular the neocortex. Some organisms have none of these, so your metric would be useless to them. A more accurate metric than the one I suggested would consider the efficiency of various physiological processes, or adaptability, for example. These are less arbitrary and more widely applicable than just focusing on the nervous system.

 

REPLY: Hello Mr.Skeptic. My whole premise is that the less complex has been evolving to the more complex at an accelerating rate. I am looking at some of your suggetions like adaptability and see how I may wish to reword my original premise. For instance: adaptability in general changes organisms from the simpler to the more complex over time. Thanks Mr. Skeptic ...Dr.Syntax

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Wrong. The neocortex is present in all mammals, therefore at least 150 million years old, possibly as old as 200 million years. This predates the entire snake adaptive radiation, flowering plants, eusocial insects, bird flight, echlocation in any form, and modern coral reefs.

 

By your logic, since snake venom glands evolved *after* the neocortex, they're a better metric of evolutionary rate. Or the ability to flower.

 

Can you give any scientific reason for using the nervous system as a metric rather than, say, the digestive system, or the muscular system? All are essential to life.

 

REPLY: No plants so flowers don`t count. Do you think a daisy is more complex than a dog ?Pterosaurs appeared 228 million years ago so wings and flight is long after mammals. I may or may not check into the rest of them as I am getting tired spending so much time running down answers for you that are simply rejected for any reason you wish to imagine. Tired of all this. If you dislike me and my posts so much why not avoid them. I do yours except when they are responses to mine. ...Dr.Syntax

[JillSwift]

REPLY: No plants so flowers don`t count. Do you think a daisy is more complex than a dog ?Pterosaurs appeared 228 million years ago so wings and flight is long after mammals. I may or may not check into the rest of them as I am getting tired spending so much time running down answers for you that are simply rejected for any reason you wish to imagine. Tired of all this. If you dislike me and my posts so much why not avoid them. I do yours except when they are responses to mine. ...Dr.Syntax

That's unfair, Syntax. Science is about questioning everything, checking every little detail to make sure it all fits. It's not personal in the least, but it is rather brutal for ideas - and that is why it works so well.

 

Mokele isn't doing anything mean, he's just asking some good questions and pointing out some weak spots in your reasoning. I gently suggest that, if you really mean to go somewhere with this acceleration hypothesis, you need to take the time to get all your ducks in a row - meaning do the research and shore up your idea.

[dr.syntax]

The evolution of life on Earth of the simpler to the more comlplex organisms. A look at the timeline of evolution is a good place to start. A very good one is available at: http://www.absoluteastronomy.com/topics/Timeline_of_evolution .We can see from this timeline that life began with the prokaryotes 3.8 billion years ago.From then it took another 1.8 billion years to evolve the simplest eukaryotes. From then another 1 billion years before the simplest multi-cellular organisms. The first fish and proto-amphibians .5 billion years later. From then another .14 billion years for true amphibians to emerge. Reptiles appear .6 billion years later.Mammals emerge .1 billion yars later. The genus homo appears .002.5 billion years later. Humans looking very much as they do today appear on the scene .0003 billion years ago. That web link I provided gives a much more detailed breakdown of the historical record along with a lot of ineresting things about the different aspects of evolution. It`s worth mentioning that many of those earlier lifeforms are still with us today. Those prokaryotes for example. Some forms of them live in your intestines and are required for the digestion of food. There are many other examples including fungi, clams,snails,sharks,all coniferous trees,and many others. The reasons for this acceleration of evolution through time is that any attribute for an organism to more rapidly change in a way that aids in it`s survival will be selected for by natural selection. The most striking examples I can think of are sexual reproduction and the intra-species competition for mating rights. It is important to note that during that long 1.8 billion years of exclusively prokaryotic life, these prokaryotes developed the ability to exchange genetic information. One of the principles I am try to illustrate is that it was the gradual accumulation over time of traits amongst the different organisms that caused this acceleration of evolution.Bacteria evolved mechanisms for exchanging partial genetic information. The three known methods are 1. transformation 2. transduction 3. conjugation . This is not sexual reproduction. For more on this go to: http://www.britannica.com/EBchecked/topic/48203/bacterial/272363/exchange_of_genetic_information . Upon further reflection it appears to me that it is likely that the ability to exchange genetic information in a progressively more efficient manner is the basis for the acceleration of biologic evolution: from the simpler to the more complex. Even intra-species competetition for mating rights is a means of refining the process of genetic information exchange. It promotes the genetic information of the most fit and able within a paticular species. Not wasting evolutionary time on the less fit and degrading the gene pool with undesirable characteristics. This may seem cruel and uncaring to some people. It does to me. But that is the way evolution works. If it were not for the total indifference of evolution to the survival of any particular individual organism , or species the process would not work and we people along all the other species would not exist. ...Dr.Syntax

 

REPLY: I retract that part of my definition of complexity as the advent of the neocortex as an organ. It is the increasing complexity of the neocortex that applies to my attempts to come up with a workable definition. It was a stupid thing to say and I knew it when I said it. I was tired and getting lazy. I made a mistake. ...Dr.Syntax

[Mr Skeptic]

In any case, isn't complexity exactly what my suggestion of information content would measure? Complexity of course being related to information content but not to any measure of quality. In fact for some circumstances, complexity is considered a bad thing, all else being equal.

[dr.syntax]

Dear SKye, please explain to me how we are metablolicaly simple. We seem to me as metabolically complex as all the other animals. And being mammals we have to maintain a specific temperature wich makes metabolism a good bit more complex than for fish or reptiles.This is in reply to post # 6. ...Dr.Syntax

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In any case, isn't complexity exactly what my suggestion of information content would measure? Complexity of course being related to information content but not to any measure of quality. In fact for some circumstances, complexity is considered a bad thing, all else being equal.

 

RESPONSE: Are we in disagreement about anything ? Information content in and of itself doesn`t work. Amoebas have 200 times as much DNA as humans do. Onions have 4 timees as much. It seems quite clear many organisms carry around a lot of useless information called DNA. I guess Amoebas never developed a proper delete button or clean up temporary internet files and simply continue to pile up useless information as they evolve on through time. Fully 95% of the human genome is useless junk.I`ve been blogging around and the numbers don`t always totally agree but they aren`t all that different. I hope you noted I am working on your suggestion of " adaptation " into this concept of complexity. I think for most people it is easy to see how a mouse is more complex than a potato. Or that a dog is more complex than a mole or a mouse. The dog`s brain is more complex than a mouse`s. A dogs brain is more complex than a lizards. A mouse`s brain is likely to be more complex than a lizard`s and there are probablly some lizards that manage to catch and eat mice. Things like that. ...Dr.Syntax

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That's unfair, Syntax. Science is about questioning everything, checking every little detail to make sure it all fits. It's not personal in the least, but it is rather brutal for ideas - and that is why it works so well.

 

Mokele isn't doing anything mean, he's just asking some good questions and pointing out some weak spots in your reasoning. I gently suggest that, if you really mean to go somewhere with this acceleration hypothesis, you need to take the time to get all your ducks in a row - meaning do the research and shore up your idea.

 

Reply: It`s just about anything I say. I posted something about some concept a number of scientists from different fields are working on. It`s called THE LATE HEAVY BOMBARDMENT. I read about it at the Absolute Astronomy website. I told about a concept a number of these scientists were looking into. He claimed they didn`t say some of the things I said they did. I told him where they did say these things. Now he says I am supposed to come up with some proof. I pointed out how I HAVEN`T SUGGESTED ANYTHING,these other people have. He never never acknowledges any mistakes he makes. He rejects any research findings of other qualified scientists out of hand. Who does he think he is ? If you want to suck up with him because he is a moderator go ahead. I don`t. ...Dr.Syntax

Edited September 26, 2009 by dr.syntax
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[CharonY]

JillSwift is being nice. The bottom line, however, is that this forum is not a personal sandbox in which you can put in some random thoughts of yours.

Read this http://www.scienceforums.net/forum/announcement.php?f=59&a=13.

I have pointed to obvious flaws in your arguments and you resort to tantrums. I did choose to ignore you because evidently I am less patient than Mokele. Mokele (repeatedly) counterpoints your arguments and you start getting personal again. Please revisit your arguments and address his points, otherwise you are just stating personal opinions without any value.

[Mokele]

You want to know the problem?

 

You're the reason we say "A little knowledge is dangerous". You clearly don't have anywhere near the level of expertise or experience you think you do, yet you feel no compunction about making definitive proclamations which are based on shoddy science at best (this thread, your other one) or are outright wrong (like the time you moronically suggested that a poster try to copyright a hypothesis).

 

Your arguement skills are poor, your information is spotty, poorly-integrated, and usually gleaned straight from Wikipedia or blogs, and you respond to the minutiae of a post rather that considering the overall substance and underlying idea.

 

I'd be considerably better disposed towards you if I didn't have to spend time correcting the errors you post in just about every thread.

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Now, as to the actual substance of your post, you have still failed to provide any empirical justification why the nervous system (or even part of it) is a better metric for "complexity" than any other system such as endocrine or muscular. All you've done is make assertions.

 

 

Science is no assertions. Either you're prepared to back up your points, or you're wasting time.