Model explains rapid transition toward division of labor in biological evolution

Jun 10, 2010

The transition from colonies of individual cells to multicellular organisms can be achieved relatively rapidly, within one million generations, according to a new mathematical model, published June 10 in the open-access journal PLoS Computational Biology, that simplifies our understanding of this process.

Biological organisms are highly complex and are comprised of many different parts that function together to ensure the survival and reproduction of the whole. How and why complexity increases in the course of evolution is a question of great scientific and philosophical significance. Biologists have identified a number of major transitions in the evolution of complexity including the origin of , eukaryotes, , multicellular organisms, and social groups in insects. A crucial step in many of these transitions is the division of labor between components of the emerging higher-level evolutionary unit.

Understanding how the division of labor evolved in multicellular organisms is difficult because single cells are expected to act selfishly to protect their own existence instead of working cooperatively to achieve a more productive higher level of organization, explains author Sergey Gavrilets, Associate Director for Scientific Activities at the National Institute for Mathematical and Biological Synthesis and a professor at the University of Tennessee-Knoxville.

His new approach applies not only to cells within an organism but may be more broadly applied to the emergence of multiple cell types, complex organs, or even some insect societies. These findings help to answer many questions for evolutionary biologists working toward understanding the major transitions in the evolution of complexity.

Using and soma cells in volvocacean as an example, Gavrilets' describes the evolutionary emergence of the division of labor starting with a colony of undifferentiated individual cells and ending with completely differentiated multicellular organisms. It is the first model to show the evolution of complete germ-soma differentiation, where one part of the colony's cells (germ) eventually specializes in reproduction and the other part of the colony's cells (soma) specializes in survival..

In the model, the division of labor occurs through the of the ability to develop in a variety of ways (developmental plasticity), meaning that some gene regulation is required. The results show that division of labor can occur if two conditions are met: there must be strong genetic relatedness and fitness trade-offs preventing individual cells from performing multiple functions efficiently.

"This particular model provides a very straightforward path for division of labor," Gavrilets said. "The model helps train our intuition about other more complex evolutionary processes."

Explore further: Human sense of fairness evolved to favor long-term cooperation

More information: Gavrilets S (2010) Rapid Transition towards the Division of Labor via Evolution of Developmental Plasticity. PLoS Comput Biol 6(6): e1000805. doi:10.1371/journal.pcbi.1000805

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kevinrtrs
1 / 5 (4) Jun 11, 2010
How and why complexity increases in the course of evolution is a question of great scientific and philosophical significance

This is a very important question indeed. All we see in every random event is that things tend to move towards the lowest energy state. Just how on earth would any evolutionary movement summon and command an increase in energy that would result in greater organisation and complexity?

The very reason this question is there and will remain there is that it goes against the laws of physics as we know it.

Those evolutionary scientists have an insurmountable and definitely unenviable task ahead of them. Good luck to them.
I certainly hope that the model they develop has more than a passing connection with reality.
Djincs
1 / 5 (3) Jun 11, 2010
Yes actually it is strange, if you compare live to how it obbays the thermodinamics it gets really no sense, we store energy when we build our bodys and everything in this univers want to get rid of energy, to build an organism it is really oposit of the chaos, we somehow manage to overcome entropy, I am not saying it gets smoller as a whole, this is inposible, but still it is weird!!!
Skeptic_Heretic
3.7 / 5 (3) Jun 11, 2010
The very reason this question is there and will remain there is that it goes against the laws of physics as we know it.
What you both don't understand is that the statements of order and complexity only apply to a closed system.

Unless either of you have rigorous boundaries for the Universe/reality then you need to relearn what thermodynamics actually says.
Djincs
1 / 5 (3) Jun 11, 2010
"What you both don't understand is that the statements of order and complexity only apply to a closed system."
Actually it is the oposite, in a closed sistem the entropy increase constantly, if you have one thing in order(low entropy) then you have lots of thing out of order(high entropy), and at the end the entropy as a whole is higher, to find order you should look only at a part of this closed sistem.
I dont say it cant be exlaned by thermodinamics but still it is interesting how there is no a matter in the world that can be compared to living matter in terms of thermodinamics(and thermodynamic is a basic rule), and still we are made by the same molecules-02, N2, C, H2, S
taka
4.5 / 5 (2) Jun 11, 2010
Control is the thing that overcomes entropy, not necessarily biological control. Any decision-making that uses information can reverse entropy (in open system of course).
Djincs
1.5 / 5 (2) Jun 11, 2010
To be honest this can happen in sistem that dont use information, like in the cristalisation of lets say NaCl out of solution then the molecules arrange in order....but never the less my poin was life is amazing in terms of thermodynamics!
Skeptic_Heretic
3 / 5 (2) Jun 11, 2010
@DJ,
You have the concept wrong.

Entropy deals with equilibrium, or states at which no further change can occur without the impact of external forces. Closed systems will always strive to hit their most stable state.

Open systems will reach their highest informational state. Without defined boundaries it is an open system.

Taka, beyond control, open system entropy is the state at which no further information can be generated, or complete homogenity.
Djincs
1.5 / 5 (2) Jun 11, 2010
No you are wrong in open sistem you have no complete homogenity it is the oposit in open sistem you can find low entropy-unhomogenity(not always), the life is example for this, and there is no such thing like "no further information can be generated" if we are talking about thermodinamics,
What I wanted to say in a furst place was just plants accumulate energy-not the whole which they gets by the sun, but still they acumulate it(there are little examples of sistems which are doing this), then when you eat them you get this aminoacids, then you arrange them to obtain specific protein(low entropy), and to bind them you include energy when you create the chemical bond between them(you get the energy from plants too), this again is something that in non living nature it is hard to be seen, to have system which increase its energy and lowers its entropy, i thing I explained it better now!!!
Djincs
1 / 5 (1) Jun 11, 2010
Maybe you are super smart and dont thing this is big deal, but when i studyed this in the university it was strange to me!
Skeptic_Heretic
3 / 5 (2) Jun 12, 2010
Maybe you are super smart and dont thing this is big deal, but when i studyed this in the university it was strange to me!

The reason why it appears strange is because you aren't taking the entire system into account. It isn't about order or disorder, it's about the lowest energy state maintenance. The general statement of entropy is A system will strive to reach its most energy stable state. In a closed system this will result in greater chaos and homogenity, in an open system this will result in the highest informational state.

You're missing about 30 years of updated research on thermodynamic principle.
Djincs
1 / 5 (1) Jun 12, 2010
"it's about the lowest energy state" man I get this pretty well I have exlaned the same thing you dont read what i have written-"if you have one thing in order(low entropy) then you have lots of thing out of order(high entropy), and at the end the entropy as a whole is higher"!
No I take the entire open sistem, the organisum is open system and it is entyre, I am not missing anything you cant understand what I am trying to say, i will give you a food for thinking, name one open system which accumulate energy and lower its entropy(non living system open system- rock, lake, planet, everything in the univerce that you can thing of), and I will accept organisms arent amaizing in terms of thermodynamics!
Skeptic_Heretic
1 / 5 (1) Jun 12, 2010
DJ, an open system is boundless. You can't quantify the energy in an open system as you don't have a boundary by which to delineate an external or internal force.

Secondly, your examples are not open systems.
Djincs
1 / 5 (1) Jun 12, 2010
An open system is one whish exchange energy and matter!!!!I am sorry but you have to learn some things about thermodynamics.
Skeptic_Heretic
1 / 5 (1) Jun 12, 2010
An open system is one whish exchange energy and matter!!!!I am sorry but you have to learn some things about thermodynamics.

No, that's wrong.
Try again: http://en.wikiped...dynamics
Djincs
1 / 5 (1) Jun 12, 2010
Come on man drop this , you know what I ment but nerev in the world will say I have my point, and here you can see what is an open system!
http://en.wikiped...c_system

Open systems: exchanging energy (heat and work) and matter with their environment. A boundary allowing matter exchange is called permeable. The ocean would be an example of an open system.
Djincs
1 / 5 (1) Jun 12, 2010
And you can rank me 1 as long as you like, I wont, it is obvious we are arguing, whats the point of ranking!
Skeptic_Heretic
1 / 5 (1) Jun 12, 2010
You really have zero knowledge of what you speak.

A bound system or closed system has NO interaction with other systems, in thermodynamics this system is not acted upon by outside forces, and as such will settle to a state of homogenity. For example a body of water in a vacuum that starts at two differing temperatures will mix to the point where the total heat content is homogenous.

And Open system is a system that is acted upon by outside forces, otherwise known as unbound, or boundless. These systems do not follow entropic laws as due to frame of reference they are always acted upon by outside forces.

Learn to understand what you're talking about. The Earth is an open system, it is acted upon by the sun, gravity, electromagnetic reception, cosmic radiation, rotational vectoring, etc. Life does not violate entropy because it does not exist within a closed system.

For evidence to this effect read up on Pasteur's experiment disproving spontaneous generation.
Djincs
1 / 5 (1) Jun 12, 2010
Ohh man I am done with you! grow up...
there is the link that i gave you , ocean is open system human is open system.....end of story
Ethelred
5 / 5 (1) Jun 15, 2010
ocean is open system human is open system.


So why did you say that it was strange in your first post?

The Second Law of Thermodynamics only applies to closed systems. You implied that the law applied to life. It doesn't. Life depends on energy from OUTSIDE and therefor the Second Law is inapplicable to life.

Ethelred

Brevity is for soulless twits.
Djincs
1 / 5 (1) Jun 15, 2010
I am not talking about furst law second law and so on, where did you saw this?
If you have read our conversation with SH , you would see that I have explaned that with OUTSIDE!
still you can use thermodynamics to estimate what is the lowering of the entropy when you sintesize a protein consisting of 150 amino acids lets say, this is a thermodynamics isnt it?
And about the energy when a organism grows it acumulate energy isn't that right- I have never mentioned that life accumulate energy and it is isolated sistem do I?...
Now if you want name one open non living sistem which is doing these two things and I will accept live isnt amazing ok, maybe there is such a sistem but I am not aware of....
Ethelred
5 / 5 (1) Jun 15, 2010
I am not talking about furst law second law and so on, where did you saw this?

Your first post.
Yes actually it is strange, if you compare live to how it obbays the thermodinamics it gets really no sense

That was a reply to the first post.
this is a thermodynamics isnt it?
Yes, if you want to look at the energy transfers. Its also chemistry. What it isn't is 'strange'.
You do know that you seemed to to be agreeing with a Creationist, don't you? HE was talking about the Second Law which he does not understand. And you appeared to agree. Which is why SH argued with you.
Now if you want name one open non living sistem
Beaches. Sand is sorted by size and density thus lowering the entropy of the sand.
Crystals form and grow through self-assembly. Sometimes even by REMOVAL of heat such as with ice.
Planets form and stars ignite by by gravitational collapse and collisions.

However they don't undergo selection so the increase in complexity is rather limited.

Ethelred
Djincs
1 / 5 (1) Jun 15, 2010
First man, never in my posts mention that humans are closed sistems, I am not talking about that part of the thermodinamics..
Second I am not creationist at all....I just admire nature..
And I actually want two things here store energy not get rid of it(non living things get rid of the energy at the furst good oportunity), beeches ok where is the storing of energy, and this with cristals you have the oposit you cant find 1 cristal that cristalizate better in high temperature...
It is the oposit, it gets more low entropy but for the prise of less energy...
to form ice water get more low entropy and with less energy!
try again
Djincs
1 / 5 (1) Jun 15, 2010
"Crystals form and grow through self-assembly. Sometimes even by REMOVAL of heat such as with ice"
And i have mention this with cristalisation of NaCl, in every cristalisation it is the same...
And this REMOVAL is necesarry for low entropy to accur....this low entropy doesnt happen against removal(with the case of cristalization ofcource)...
i suppose you know sh#ts about thermodynamics....
Ethelred
5 / 5 (1) Jun 15, 2010
I am not talking about that part of the thermodinamics..
Actually you did. You agreed with someone that was doing that. Unintentionally apparently but still that was what your first post came out as.
, beeches ok where is the storing of energy,
Waves move large items up the beach and then strand them. Higher, therefor with more potential energy.
you cant find 1 cristal that cristalizate better in high temperature...
Creationist or not you have a similarity in one thing at least with them. An unwillingness to look for ways you might be wrong.

In other words SUGAR crystals form faster from a solution if the temperature is higher.
i suppose you know sh#ts about thermodynamics...
I suppose you know crap about chemistry and crystallization.

Shit is a high entropy result of life. Also a sign that you have a vocabulary problem.

Ethelred
Djincs
1 / 5 (1) Jun 15, 2010
Yes my english sux i admit, but that is another thing lets leave this.
My first comment I read it again and i dont see anything wrong..
And the beach example is really not a good example, furst i cant agree that the entropy is really low there, a really small order I see the fact that the slightly heavier are at the bottom, doesnt make it low entropy(the things that are in mess-lets say the different types of sands grains make it high entropy as a whole)(when in the ocean the wather is at the top and the sand is at the bottom is this a low entropy), and the accumulation of potential energy somehow sux(but never the less good logic i admit)...
and your example with the suger isnt right man I am sorry try to desolve suger in hot water and in cold water and you can see where it will be faster...
Djincs
1 / 5 (1) Jun 15, 2010
You just cant make a high energy molecule(moving faster)to join the cristal easyer...
Ethelred
5 / 5 (1) Jun 15, 2010
My first comment I read it again and i dont see anything wrong
That you thought the thermodynamics of life is strange is, if not wrong, then rather odd for a person engaged in rational thought. Life obeys the rules of the universe. Any appearance to the contrary is a misunderstanding.
And the beach example is really not a good example
For off the top of my head its OK.
doesnt make it low entropy
Not the point. It was a decrease in entropy due to the input of external energy.
I am sorry try to desolve suger in hot water and in cold water and you can see where it will be faster
Its the removal of water by evaporation that increases with heat. High rates of evaporation will decrease the crystal size. I am simply pointing out that self-assembly does occur.
You just cant make a high energy molecule(moving faster)to join the cristal easyer
True. But you can increase the density of the solute by heating the solution thus driving off water.

Ethelred
Djincs
1 / 5 (1) Jun 15, 2010
"True. But you can increase the density of the solute by heating the solution thus driving off water."
yes but this is another story man you are slippery too....
and this thing with the sand I dont know man, i thing just chaos is greater in the sand compared to some kind of order, I am pretty shure it is high entropy, but now I am sick with this....but maybe someone with more knowledge can solve the argument, to argue only two of us is pointless..
Skeptic_Heretic
1 / 5 (1) Jun 15, 2010
to argue only two of us is pointless..
You mean 3 of us.
Djincs
1 / 5 (1) Jun 15, 2010
Thats better, trolling is important thing somebody has to do it...
what if there are no creationists, i dont want to live in such a world!
Skeptic_Heretic
1 / 5 (1) Jun 15, 2010
Thats better, trolling is important thing somebody has to do it...
what if there are no creationists, i dont want to live in such a world!
Mind if I ask why?

If the world wasn't created by magic, and there isn't a personal god that controls your daily actions and thoughts, wouldn't you feel more free? I feel empowered by realizing that yes, man can do anything they set out to do.

Tossing off the yoke of metaphysical slavery is not a bad thing.
Djincs
not rated yet Jun 15, 2010
No man i am talking that here and in other places the god thing is really comon argument-is there one or there isnt, but if there are no people to argue with on this theme, well it will be much boring, everybody to beleve in the same things, this will lead to low entropy(homogenity) and low energy = boredom so to speack...
I dont beleave in any god like powers dont get me wrong...
thats why on every topic you can find people with different opinion, and we are 99,9% alike, a bit of trolling is responsible i beleave
Skeptic_Heretic
3.7 / 5 (3) Jun 15, 2010
but if there are no people to argue with on this theme, well it will be much boring, everybody to beleve in the same things, this will lead to low entropy(homogenity) and low energy = boredom so to speack...
I don't necessarily see that as a bad thing. There are a great many other topics we can argue about as a species, primarily centered around "How do we make life better for everyone?"

I'd rather have conversations about making the planet better for everyone than have conversations about how to get into some fantasy idyllic place that doesn't exist and no one has proof of while those same people suffer and die around me due to the conversation.
Djincs
1 / 5 (1) Jun 15, 2010
See some people got to bileave in something like that. Not everybody can cope with the nihilism(the poinles of everything) that sciense shows us, it tells us that we have common origin with the kockroach, some people cant even accept the monkey, now you and Ethelred are trying to convince me that we are not much different from a bunch of sand.....
the science allso tells us everything will be gone some day.
chek the theory-entropy of the univerce, there will be a point in the time that no energy will be available, and game over....all the great things that evolution has created and all we have created will be gone...
i wish i didnt knew that man, i wish to beleave in something magical and that everything got its purpous, it is much easyer.....
Skeptic_Heretic
3 / 5 (2) Jun 15, 2010
Not everybody can cope with the nihilism(the poinles of everything) that sciense shows us,
Whoa, when did science lead to nihilism? Only comming from a deeply religious framework can one state that without religion man has nothing.
it tells us that we have common origin with the kockroach, some people cant even accept the monkey, now you and Ethelred are trying to convince me that we are not much different from a bunch of sand.....
No, no. We are different from a bunch of sand, VERY different, but, the same mechanics that govern sand, govern us. This adds an incomprehensible beauty to all forms of life as they wander through reality as long chain chemical reactions.
the science allso tells us everything will be gone some day.
Not possible. You can't turn something into nothing.
i wish i didnt knew that man, i wish to beleave in something magical and that everything got its purpous, it is much easyer
Easier isn't always better. And we can always escape.
Djincs
not rated yet Jun 15, 2010
"Not possible. You can't turn something into nothing."
I feel like i am teling you there is no santa:

Entropy and cosmology

Main articles: Heat death of the universe and Black hole thermodynamics

Since a finite universe is an isolated system then, by the Second Law of Thermodynamics, its total entropy is constantly increasing. It has been speculated, since the 19th century, that the universe is fated to a heat death in which all the energy ends up as a homogeneous distribution of thermal energy, so that no more work can be extracted from any source.

this is copy pasted it is not my work, you can be shure because there is no gramatic mistakes in it i suppose.
this is the nihilistic part of the science, and science dont answere a big question whats the point of existance?
Skeptic_Heretic
3 / 5 (2) Jun 15, 2010
I'm not disagreing with what you've posted, but at no point in time does that mean the universe will become nothing.

Conservation of energy states that energy cannot be created or destroyed. The statement of thermodynamics in an open system is that energy will become ever more diffuse. Effectively you cannot have an efficiency of 1, there must always be a loss (through diffusion). Again, the universe won't die a heat death, it will simply become so diffuse as to be alien to what we think we can account for within our current physical framework.

This is the reasoning for the term "Heat death" as energy will become so diffuse as to be unable for matter to form as energy density will be so low. Now, there's a lot of interesting things poking at us from behind theory. It appears that the Universe may indeed go through state changes, and if that's the case, who knows. Perhaps dark matter will "cool" to become baryonic, or perhaps vice versa. It's too early in our understanding.
Djincs
not rated yet Jun 15, 2010
What I see in a state of heat death, there is no humans no nature , nothing happens-this is depresing man thats what i ment about science-nihilism thing, I wish it is not true but the theory is really good this is what happen in any isolated system...there is no escaping, and science tells you that we are just coincidense we are not ment to be , nobody care that this is going to happen, there is no force to come and save us....see i have learned to beleave in science 100% and not to beleave what i want to beleave because it is good for me - this cuts my hopes
and whats the point of existance anyway?
Javinator
5 / 5 (1) Jun 15, 2010
I have a feeling you'll die well before the universe becomes homogeneous.

If you choose to take the information science gives you and you want to become a nihilst that's your choice. It doesn't mean science forces nihilism on people. A good number of scientists and scientific folk are not nihilistic and have decided to find purpose in their lives in their own ways.
Djincs
not rated yet Jun 15, 2010
i eat healty food who nows?
I am not a nihilist... yet, i am too young to be one....And i thing it is not a matter of wanting, who wants to be!
I just wants to answer the guestion of purpous troug science and it gets nowhere, dead end...
The goal of life is to create more life, its seams to me that the bacteria and human have the same meaning in life- to reproduse and then again and then again, and then a little bit of changings(evolution)and thats it, somehow it is not cool.
A good purpous would be to find way to over come the heat death but you cant....
Skeptic_Heretic
3 / 5 (2) Jun 15, 2010
I am not a nihilist... yet, i am too young to be one....And i thing it is not a matter of wanting, who wants to be!
Most nihilists are young. They haven't experienced enough life to realize why it's so valuable.
Ethelred
5 / 5 (1) Jun 16, 2010
Not everybody can cope with the nihilism(the poinles of everything) that sciense shows us,
What is the point for other animals? They don't seem to be into nihilism. Existence doesn't need a point as there couldn't be any kind of point at all without existence. Of course nothing would have noticed existence if life hadn't arisen and then evolved intelligence. At which point the Point became continued existence since the alternative was to become extinct.
now you and Ethelred are trying to convince me that we are not much different from a bunch of sand
Quite different. Sand can't reproduce and therefor isn't subject to Natural Selection which is the source the increasing complexity of life over time.
science allso tells us everything will be gone some day.
I promise you that Math will still exist. There might not be anything to notice or to explore it.
it is much easyer.
No one said that accepting reality was easy. But it isn't boring.

Ethelred
Djincs
not rated yet Jun 16, 2010
Actually I like that you mentioned animals, i do beleave that we are not so different after all.
but you see I was saying the reasons for lots of people not to axept science logic and to beleave in something more "cool"(i know there arent such things). Some people axept the evolution but stil they thing that in order for life to understand its own existance there must to be something behind that....lots of physicists and other scientists beleave that something more exist, they just dont want this reproduction all over again to be the point, I am not saying it is boring, maybe depresing and not inspiaring, or simply not cool and flat.the religions are really oldfasion, now another forms of not scientific forms of beleafs are appearing(even dummer but the problem for so many people to be so naive is that biology and chemistry are underestimated in scool from the magority of the children), it wont be long before someone finds out how to make money from that.
hylozoic
not rated yet Jul 16, 2010
Psst:
Most nihilists are young. They haven't experienced enough life to realize why it's so valuable.
Beautiful. Assertion seconded!
marjon
not rated yet Jul 16, 2010
In economics it is called comparative advantage.