Model explains rapid transition toward division of labor in biological evolution

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."


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Why Evolution Drives Some Cells to Altruism

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
Citation: Model explains rapid transition toward division of labor in biological evolution (2010, June 10) retrieved 23 July 2019 from https://phys.org/news/2010-06-rapid-transition-division-labor-biological.html
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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.

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.

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).

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.

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.

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.

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

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.

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.

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

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

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

Jun 15, 2010
to argue only two of us is pointless..
You mean 3 of us.

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.

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.

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.

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.

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.

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.

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

Jul 16, 2010
Psst:
Most nihilists are young. They haven't experienced enough life to realize why it's so valuable.
Beautiful. Assertion seconded!

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