ADRIAAN

Life and the Evolution of Sex

2008-10-08T11:56:00.017+02:00

Life is a replicating molecule. This replication is imperfect and sometimes errors in the copying of the replicator occur. The evolution of life is best understood as the replicator 'sliding down the hill of replication errors'.

See the diagram below, each red dot is a replicator that is still alive today. Every mutation that manages to crowd out the original or split off makes the replicator drop downhill. Uphill we find the least-mutated life forms still alive today. Towards the bottom of the hill we find the most-mutated forms still alive today. All life forms originate from the top, from the same replicating source, and have been alive for the same amount of time.

Nothing that happens downhill can serve as an explanation for anything uphill, because faulty replication is not a process that can look ahead in any way. Downhill, replication generally becomes more energy intensive and the replicator becomes more vulnerable to external disturbances due to the specialisation on specific energy sources. This vulnerability causes most life forms to die out as they slip further downhill.

Sexual reproduction.
A mutation to a replicator stumbles upon sexual reproduction. Now mutations that survive without fixating are allowed to build up among the sexually reproducing organisms. Sexual reproduction changes the single gene line into a gene pool of genetic diversity available to the replicator.

The introduction of a gene pool causes two important changes to life:

1. A replicator building its organisms from a gene pool gets an extra lease of life because it gains a resistance against external disturbances. It can adapt within the gene pool without further mutations (like the peppered moth being able to adapt to the colour of the trees) keeping the replicator alive for longer. The genetic diversity within the genepool acts as a buffer against external disturbances allowing the replicator code to stay alive through genetic recombination.

2. The sexually reproducing replicator becomes more vulnerable to mutations, causing increased complexity and speciation. A mutated gene can recombine in many more ways than before. This increases the chance of finding a combination that is capable of crowding out the original or splitting off, causing it to drop down the hill.

But these two effects can not be the cause of sex appearing in evolution. They occur downhill from where sexual reproduction first occurs, after the build-up of a gene pool by further mutations.

The cause of sexual reproduction is the increased energy efficiency offered by building in an error prevention and correction mechanism in the replication process, allowing the mutated replicator code to crowd out its original. Sexual reproduction prevents the replicator from wasting energy on building faulty organisms that won't make it to replication (see earlier posts). This lets the sexually replicating version achieve a higher growth rate on the available resources, crowding out the original.

Cause and effect of sexual reproduction.
This clear distinction between horizontal 'adaptation within the genepool' and vertical 'mutation downhill' can explain the cause and effects of sexual reproduction. The abundance of sexually reproducing life in today's world is due to the buffer a genepool provides against external disturbances and the increased vulnerability of the replicator to mutations that can take over or split off. Sexually reproducing life is caused by a mutation introducing an error check in replication which allowed it to crowd out the original.

Present theories on evolution lead to confusion because they clump together adaptation within the genepool and mutation 'downhill' into a general mechanism called adaptation/evolution. To understand the cause and effect of sexual reproduction, these two aspects of life need to be clearly separated, like the model of the 'hill of replication errors' does.

Adaptation happens only within the genepool (by my definition). It is a largely reversible, almost directed process. Life is bound to find the 'best' genetic combination, given enough time for genetic recombination. Adaptation is about organisms within one species outperforming each other. Adaptation can occur without changing the potentially available code to the replicator. Adaptation can be seen as the replicator moving horizontally on the hill.

Mutation downhill is a largely non-reversible, pure chance process. Due to its path dependent chaotic nature it is very hard to predict where it will go. Mutation is about permanent changes in the code available to the replicator, these are changes that affect the species in general. Mutations can open up long avenues of adaptation that life can take at great speed. This could give rise to 'sudden' large changes in a species phenotype. Mutations can be seen as the replicator slipping down the hill.

Both adaptation and mutation happen because changes in the organisms phenotype give it certain advantages over others within the same species. The difference is in whether it takes 'new code' or not.

I think the model of the 'replicator sliding down the hill of replication errors' may give more insight into the cause and effects of sexual reproduction. I would be happy with any comment.

Life and the Evolution of Sex.

2008-10-06T21:16:00.046+02:00

DRAFT

Life is a replicating molecule. This molecule can go on replicating until a copying error creates a mutation that either manages to crowd it out or split off.

This mutation is not necessarily an 'improvement' to the replicating molecule. The replicator often gets pushed into a corner where replication takes more energy, or where it is more vulnerable to external disturbances due to an increasing specialisation on specific sources of energy. So most replicators won't slide down the hill of replication errors very far before dying out.

The picture below shows life sliding downhill as it mutates. The least mutated life forms at the top, the most mutated life forms near the lower end. Every red dot is a life form that is still alive today. The ending black lines are life forms that have died out in the past.

Looking at the sliding slope of replication errors, nothing downhill can be used as an explanation for anything uphill. Replication with its errors is not a process that can 'look ahead' in any way.

At some point sexual reproduction transforms the single gene line into a gene pool as shown in the enlargement.

Sexual reproduction, cause and effect.
By a chance mutation the replicating molecule hits upon the mechanism of sexual reproduction. Reproducing sexually makes it possible for the code to achieve a higher growth rate out of existing resources, because it doesn't waste energy on building faulty organisms. It provides an error check, see earlier post. At every mutation further enhancing sexual reproduction, an extra error check got built in making the code more energy efficient in reproduction than its original.

Downhill, after further mutations have built up, the single gene line of the replicator becomes a wider gene pool. Mutations that are viable but that do not make it as the species standard create genetic diversity. From this genetic diversity, organisms can be built in slightly different varieties using genetic recombination.

Once the code replicates from a gene pool rather than a single gene line, two important changes in life happen:

First, life can adapt within the gene pool without further mutations, which gives it increased resistance against external disturbances. That is why sexually reproducing species manage to stay alive for longer. (The peppered moth can turn white or black depending on external circumstances, without needing any mutations. A recombination of existing genetic variation can be enough.)

Second, the gene pool makes it possible to recombine a mutated gene in many ways, increasing the chance of hitting upon a version that can crowd out the original, or split off. So sexually reproducing replicators are more instable, which explains the explosion of species reproducing sexually.

The protection against external disturbances and the increased speciation are the result of sexual reproduction. But not the cause. Simply because these effects only happen further downhill from the first appearance of sexual reproduction. Sexual reproduction could evolve because it offered a more energy efficient way of reproducing, that is why the code that uses it prevailed.

A better theory of life.
This model explains how sex could evolve (more energy efficient reproduction) and why there is so much of it around today. (Adaptation within the gene pool provides protection against external disturbances. Sexual reproduction increases vulnerability to mutations increasing speciation.)

Organisms can adapt within the gene pool. This is a reversible and not entirely random process. Adaptation is bound to find the 'white or black' version from existing genetic diversity if the benefit is large enough.

Life mutates downhill. This is an irreversible, pure chance and unpredictable process. Evolution downhill follows a path dependent direction making it hard to predict where it will go.

The model shows how earlier theories of evolution had to lead to confusion. They clumped together adaptation by genetic recombination within the gene pool and the separate evolution downhill by genetic mutation. To understand the cause and effect of sexual reproduction, these two mechanisms in life must be looked at separately.
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Life from the Perspective of the Single Genome per Species.

2008-10-01T15:32:00.013+02:00

Life is a replicating molecule called the genome. To understand every aspect of life, we only need to look at the effect it has on the replication of this single genome per species.

What makes life possible is replication. To a genome, the choice between change or no change is literally a no-brainer. Only those genomes that achieve a high degree of error-free replication manage to stay around, all others will have perished a long time ago.

The genome under perfect replication:
The genome has no number dimension.
Whether it codes for 100 or 100 million organisms, it is still the same genome in every organism. There is only ONE genome per species. It either exists, or it doesn't. The number of organisms is only relevant when there is safety in numbers, because whenever the organism count hits 0 the genome is gone.

The genome has no time dimension.
The genome codes for an organism that replicates itself, bringing the genome back to where it was before the life of the organism started. So while the organism lives and changes over time, the genome does not. To the genome, time makes a perfect circle every generation.

All the organisms the genome ever codes for have one use only, and that is the replication of this single genome per species. So the fortunes of all the organisms from the genome's perspective are interchangeable. A benefit the genome gets in replication from one organism can be covered by a cost to any other organism it codes for. Because there is no time or number dimension, cost and benefits in terms of replication can be collapsed over all generations and individuals, as long as the organism count always stays positive.

The genome with imperfect replication.
Life is all about replication of the single genome per species. The replication process is imperfect, so every now and then the genome encounters a change in an individual organism it codes for. This change usually stops the organism from replicating. Sometimes the mutation improves replication in the short run and the mutated genome in the single organism can spread and make it to become the species standard. This is evolution. Evolution happens when replication fails.

The circular cost-benefit analysis from the genome's perspective show the weaknesses in its replication. A mutation in the direction of a profit could overtake it. Mutations that benefit others at a loss to the organism can evolve if they can make it to the position where the organism also gets to be on the receiving end of the deal. A subsequent cheater may get a profit at first, but soon it will find itself surrounded by cheaters and it loses the benefit it was after. So the circular cost-benefit is the overriding constraint to possible change in the genome by failures in replication.

All aspects of life can be explained by looking at the perspective of the single genome per species.
The genome needs to do only one thing: stay alive and replicating in at least one organism. To look at the effect of specific behaviours of the organism the genome codes for, we must also remember that life from the genome's perspective is circular over all individuals and generations.

Parental care.
The genome can code for an organism to take care of its young at great cost, and recover the cost by having the organism taken care of when it is young. If the net benefit on replication is positive, this makes sense from the single genome's perspective. Family ties are common in the animal world because they are fairly easy to program in and reliably lead to a net benefit in reproduction of the single genome.

This means that from the genome's perspective, you do not take care of your children because they take 'your genes' into the future. You take care of your children because the genome that codes for it also makes your parents take care of you. And the net benefit in terms of replication is positive to the genome. The specific genetic combination that makes up an individual human gets shuffled up in the gene pool in no-time and is not a lasting entity.

Sexual reproduction.
Sexual reproduction is all about replication error prevention and correction.

The first stage of sexual reproduction is swapping individual pieces of code (genes) before reproducing while keeping both copies in the organism. When one gene fails in building the organism, it can fall back on the other. This increases the reliability in copying the entire genome and improves the security of reproducing the single genome per species. This improved copying is beneficial to the genome from the start and can increase right up to swapping 50% of the code in small functional pieces.

The second stage is male/female specialisation. This allows more distance between the fertilizing male and the reproducing female and lowers the chance of encountering the same errors in a code swap. This further increases the reliability in the copying of the genome and makes it more likely for the single genome per species to continue.

The third stage is male competition. The female side gets to select the least damaged code from the males. This can act as a circuit breaker stopping damaged pieces of code from continuing in the circle of life. Damaged genes will be present in both females and males, but they can be filtered out on the male side improving the integrity of the single genome and improving its long term chances.

Sexual reproduction is a copy control mechanism in the replication of the single genome per species. Because it allows for some males to out-reproduce others, it can accelerate the spread of a changed genome. But while sexual selection can speed up evolutionary change, its function is only to improve the reliability in the copying of the single genome per species.

The 'species genome' is the narrow band of genetic variation you find within a single species. Pulled apart by viable failures in replication(evolution) and pulled together by sexual reproduction. Sexual reproduction could evolve because at every step it provided a benefit in the error free copying of the genome. And since the vast majority of mutations hurt rather than help in replication, that is a tremendous advantage.

The difference between replication and evolution is a major cause of confusion. Replication is about keeping the single genome per species alive. Evolution is the change of the genome which can start with a single gene in a single organism out competing others and becoming the species standard. Evolution of life is about changes to the genome, life is about replication of the genome. 'Sexual selection' is a part of replication, 'natural selection' belongs to evolution.

Cooperation and competition in humans.
The single genome per species can improve on its replication by having the organism it codes for cooperate. Even though humans share practically 100% of the genome with each other, the genome has coded in a tolerance for diverging face structures. This is our individual signature that enables us to recognize each other and cooperate. Just like the cat genome uses differing scents and the bird genome uses differing vocal calls, the human genome uses variable face structure to improve its replication by enabling cooperation.

Humans are practically clones, they only differ for as much as it helps the single human genome to improve its replication by enabling humans to cooperate. You would never get your bike back if you couldn't tell who you gave it to.

Competition in humans comes from the sexual selection mechanism. For individual males to make it through it helps to outperform other males. Because of the high parental investment by both sides in humans, the mechanism of sexual selection to maintain gene quality can be used in both males and females by the single human genome.

Cainism among raptors.
Some birds have the elder chick throw the younger one from the nest. This makes sense from the single genome per species perspective because it increases the likelihood of the genome to make it into the next generation in at least one organism.

Short term view of evolution.
For a change in the genome to make it as the species standard, all it has to do is crowd out the alternative. So even though a single gene change can be beneficial in replication in the beginning, that says nothing about its effect in the long run. Language may have evolved in humans as a result of a changing muscle structure releasing the jaws and improving humans ability to speak and think. In the short run this changed genome managed to make it as the species standard. In the longer run it has led to humans exhausting their environment. So while the benefit to the reproduction of the genome is there, the cost is yet to come.

To a nomadic species like humans, exhausting the environment before moving on is a matter of efficiency. Only this time there is nowhere left to go.

Punctuated Equilibrium.
Life from the perspective of the single genome per species is entirely circular. This often causes balancing acts in life, such as for the level of parental care in animals. When parental care evolved this must have been beneficial to the replication of the genome. In humans, it could then evolve further by chance mutations over many generations to the level of almost two decades. So qualitative changes in the building plan of the organism can open up long avenues of further quantitative evolution.

Life falling apart.
Many people see life as building ever more complicated structures, somehow improving on complexity and diversity. But from the perspective of the single replicating genome, evolution is about breaking down. The genome was alive, brakes and is rescued by more complicated way of replicating. Every mutation leads to a more complicated way to hang on to life, while closing off the way back.

From the single genome's perspective, the evolutionary change in the organism it codes for is due to a succession of failures in replication. These changes usually make the genome more instable as can be seen by the accelerating speciation once a genome diverges from its simplest and safest form. It is pushed in an ever tighter corner and generally dies out due to the increased vulnerability. A mutation profit in the circular cost-benefit in terms of reproduction shows where the genome's weaknesses are.

Hamilton's rule.
Hamilton's rule states that the effort an organism spends on another organism can improve genetic fitness for as long as the cost is lower that the benefit adjusted by its degree of genetic relatedness. While this makes a difference for a gene that isn't the species standard, to a standard gene all organisms within the species are 100% related and Hamilton's rule is the same as the circular cost-benefit view from the perspective of the single genome per species.

The Circle of Life.

2008-09-24T23:16:00.024+02:00

Darwin's theory of evolution provides an elegant explanation for the diversity of life we see around us. The genes that code for every living organism sometimes encounter a mutation that proves viable and creates a slightly changed living organism. The accumulation of mutations and occasional speciation causes organisms to evolve and diverge in time, and this creates the great complexity and variety of life we see around us.

But gene mutations that change an organism are rare events compared to the lifespan of a single organism. Genes use very effective mechanisms to prevent and correct errors in the copying of the genome (1). Life seems to get on just fine in the time it spends in between mutations. So while the theory of the evolution of life may explain the great diversity of life, it does not explain life itself. The theory of the evolution of life relies on the mutations of the gene. A theory of life should rely only on the gene, because life does not need evolution to stay alive.

Life with sunscreen.

If we put mutations of the genes aside for a moment, organisms move through time business as usual. Humans are born as the children of their parents, live their life, have children of their own and pass away. But if we look at the genes present in humans, they can move from generation to generation completely unchanged. This means that these genes do not live 'in time' in the same way that we do, because they do not change over time. They either exist, or they don't.

The organism that carries the gene brings the gene back exactly to where it was before the organism's life started. So life, from the gene's perspective makes a perfect circle every generation and the gene gets to stay for as long as the organism it codes for manages to reproduce. It is this circle of life that makes the logic of the genes different from what we are used to. A single organism can spend energy in order to gain resources to live and when the net benefit is positive, this is behaviour that can help bring the organism closer towards reproduction. But in the circular gene-centred view, the fortunes of all the organisms it is a part of are interchangeable. A benefit in reproduction to one organism can be covered by a cost to any other organism it codes for. As long as the net result is positive, it makes sense from the gene's point of view.

In practical terms, a gene can code for an organism to take care of its children at great cost, and recover the cost by having the organism taken care of as a child. If the net effect on reproduction is positive, this is a good investment. This means that from the gene's perspective, you do not take care of your children because they carry 'your genes' into the future. You take care of your children because the gene that codes for it, also made your parents take care of you. And this was a good investment of effort, otherwise the gene would not have been able to exist.

The organism that takes care of its children, gets taken care of as a child. If the net effect of this investment in parental care is positive, it can increase right up to the point where the marginal return on extra parental effort reaches zero. For some species this means a couple of seconds, for humans this means almost two decades. Given the helplessness of a newborn child and the relative strength of the parents, the benefits of such an arrangement are obvious.

The cost to an organism carrying the gene can be recovered by a benefit to any other organism carrying the same gene. The essence of interactions of an organism with the outside world is not that the beneficiary is related or not. The essence is that the cost reliably leads to a benefit to an organism carrying the same gene. The benefits and costs can be spread out over multiple organisms and across generations, it is the statistical average profit in terms of reproduction that matters.

It is this reliability in getting a return on the investment that makes interactions with family such an attractive proposition in the animal world. It is fairly easy for the gene to point the organism to the right benefactor, so no effort is lost due to one organism receiving double the help and another getting nothing, this would not add up to the same average benefit in reproduction. Imagine the mother that could not tell its young apart. The effort the mother makes in parental care could end up with just one of its offspring, leaving the mother with one starving young and one overfed. The average reproduction of the three combined would plummet. Luckily, many animals can divide their efforts correctly over their young and parental care is a common investment as a result. Just like taking care of your child means you get taken care of as a child, taking care of your brothers means your brothers will look after you. And that can be a good investment in some species. It certainly is in humans.

Life with genetic mutations.

The gene centred view on life can be used to understand what mutations to the genes are viable. Because life from the genes perspective is circular, we can collapse the effect of the mutation on all organisms the gene codes for and consider only the average effect on the reproduction of the organisms that carry the mutation (2). New adaptations need to lead to an increase in the average reproduction to spread and become the new standard for the species. For genetic mutations that involve interactions within the species, the circular effect must be taken into account. Genetic mutations surround an organism much quicker than they can evolve further so the overriding constraint to a mutations viability is that it can make a profit from living among itself.

The complicated feedback an organism gets from being surrounded by other organisms carrying the same gene, often creates a balancing act within life. Take parental care. Any female with some surplus resources could have started this. And when parental care appeared ('this thing I just dropped is actually quite cute.'), it must have been a profitable investment of effort. Parental care could then increase by further chance mutations right up to the point where the marginal cost balances the benefit. But for parental care among humans to evolve all the way up to the present level of nearly two decades, it will have taken many generations of slow evolution.

So qualitative changes in an organism's building plan can open up long avenues of further quantitative evolution. We may have seen this following the recent appearance of language in humans and its subsequent effect on cooperation and thinking. It opened many new avenues of profitable evolution (in brain power, for example) towards a new balance. Whether it is a viable mutation remains to be seen. Looking at humanity's effect on its environment, it isn't looking all good.

Conclusion

Darwin's theory of evolution showed us how we could have evolved over a very long time from the simplest living organism, via a fish-, reptile- and apelike creature into what we are today. The downside of its success has been that it has made people see all of life as a continuous line from the past into the future.

But without the occasional mutations of the gene, life is better thought of as a perfect circle in the present. Like a blind investor, life puts energy into its surroundings in the quiet faith of a positive return. Family members are important in life not because they are related, but because they are reliable.

1. Sexual reproduction works as a copy control mechanism. It provides several lines of defence against errors propagating in the gene pool. First it lets organisms of the same species swap code in reproduction, keeping both copies. If the gene from one side is defective, it can still use the other. The second line of defence is the specialisation in a reproducing female and a fertilizing male. This limits the chance of encountering the same errors in a gene swap by allowing more distance between the sexes. The third line of defence is sexual competition among the males. The female side that takes care of the actual reproduction gets to choose the least damaged code from among the males. This acts as a circuit breaker preventing broken genes from continuing in the cycle.

2. To become the species standard it needs to make the organism it codes for outperform relative to those with the alternative gene, without making the organism count hit zero. A higher average reproduction will do that, but there are more ways.

From a gene's perspective, there is no such thing as a beneficial mutation. What we see as a beneficial mutation is just one that the gene couldn't stop, as much as it tried. The struggle for life from a single gene's perspective is only about staying the same. Evolution happens because the copying process is imperfect. Evolution is the continued and accelerating destruction of the replicating molecule, those lines that survive need ever more elaborate mechanism to hang on to life.

Hamilton's rule states that a gene can benefit from having the organism it codes for aiding another organism as long as the the cost in terms of reproduction is lower than the benefit adjusted by the degree of genetic relatedness. For genes that are the species standard, all other organism are 100% related and it comes back to the circular gene centred view of life.

Why sports and career can feel like matters of life and death.

2008-08-01T09:23:00.011+02:00

Why are men more interested in sports and a career then women? Sure, many women follow sports, but for men its seems sometimes they can't live without it. And while many women successfully pursue a career, it is the men that give it a higher priority in their life .

I believe it is our evolutionary background as hunter-gatherers that holds the key to explaining this behaviour. And once you see the goal of the effort people put into finishing first, you will also see why this same behaviour may be getting us into trouble in today’s world..

Humans evolved as hunter-gatherers over millions of years on the African savannah. The woman gathering and the men hunting, although those lines would not have been so black and white. We were shaped by the behaviours that helped us survive in that environment. And we still carry many of the motivations behind those behaviours with us today. Only recently did humans evolve language and did our brains stumble upon the power of 'parallel processing' together. We talked our way out of the savannah. And then writing, book printing and the internet catapulted us into the urban world we see around us today, where we can combine the thoughts of all the people around us and before us and act faster and more intelligent than ever.

What has gotten lost in the rush is the fact that the rest of our brain and body didn’t really evolve out of the savannah, it just walked out. We still think like the social apes that we are. The apes that were busy enough trying to secure food and find the best possible partner. The problem of finding a partner is still with us. But we solved the food problem. If we need it, we know where we can find it. Where women spent time gathering fruits and vegetables and where men went out on the hunt, now they can go to the supermarket around the corner and find more food then ever.

It is these methods we used to find food, that have shaped much of our social structure. Coalitions and hierarchies are based around how instrumental you are to others in them getting their food. Success in gathering fruits and vegetables depends on the quality of your information network, and on your ability to show it off. You rely on others telling you where the latest fruiting tree is. Female status is about who hears it first. Today’s women still show off the quality of their information network with signals like gossip and clothing. (See earlier post). For men, hunting was the way they brought in their share of the family’s food. And it is the requirements in hunting that have shaped the social structure among men.

Hunting is a team effort. Whether you drive the animals towards your fellow hunters, or whether you track and stone the bigger ones, you are much better off going with a few others. But while you need others to hunt successfully, you don’t want to bring anyone along that can’t pull his own weight. Why bother going out with the guy that slows you down in the running, or that is too dumb to understand when to be quiet. Nobody wants to share the meat and the glory with a slacker. For a male to do well in hunting, he needs to earn his place in the best team going out to hunt. That is what guarantees him and his family a regular supply of meat.

How do you get yourself on the best hunting team out there, and not the second or the third? Of course you make sure everybody notices you with yet another catch after every successful hunt. But any other physical contest you can do with other men in the group can serve to impress. Depending on the intended catch, there may be a place for a good runner, an experienced tracker, a thrower or a very strong guy. Even the weakest guy can still make a good addition to the team if he is very smart. So you have an incentive to compete in any playful contest there is, earning your place in the upper league. Make sure you get that trophy that shows you are a winner and that you could well be the ‘most valued player’ in the hunt next time around.

The diverse team nature of hunting is the reason why men are so eager to compete in any game whenever they can. And why it is so much about impressing other men. It is the other men that decide who comes along with them and who doesn’t. Sure, girls better take note of who brings in the meat and who doesn’t. But to them so many more things matter, like showing good health and appearing to make a faithful partner and a devoted father. The men couldn’t care less. They want to see you bleed. And when anyone else in your team takes part in a contest, support him because if he wins, your hunting party will attract the best young ones out there. Competing in games against neighbouring groups may be a good pasttime. But the population density throughout evolution has been too low to consider that the reason behind playing games as much as we do.

Your male brain pushes you to get into the best team you possibly can. Because the meat out there isn’t going to wait. So it drives you to take on any challenge until you are secure in your place. In a small group, there is an end to these displays of prowess. At some point it is clear where everybody stands and the displays become few and far between. Why would you go to the limit in head to head contests when it is clear that you are in the right spot. The next guy up really is better than you and the next guy down still has a lot to learn. The displays calm down when everybody knows where everybody stands.

What would happen if you made the group much bigger, like it has happened in our modern time? For men, changing the game hasn’t meant much. If your game is about making money, you show your trophies in the car park and you talk about your income in the bar. If it is about writing scientific papers, everybody can see the citations. Only now there is always a higher league to get into. And when you compare yourself to your peers, suddenly you can’t be so sure of your place any more. The next guy up and the next guy down seem awfully close in their winnings.

Even though our social circle isn’t that much bigger than it used to be, it has become much more homogeneous. The schooling system, the housing arrangements and our work floor have sorted us along the lines of our abilities. In your first school you knew exactly where everybody stood at the end of the year. Then the class got separated, and each pupil went on with others of his own level. And sometimes that happens to people several times until the people around them are practically indistinguishable in talent. That tells your brain to keep up the displays, else you may lose out on food in the hunt.

As social primates on the savannah, human males used every possible contest to sort out who gets to be in the best position for the hunt. Our determination to get to the highest team has determined our survival and is still with us today. But the mechanism is incompatible with our increased group size. The hunter has become stuck in his display behaviour, exhausting not only himself, but also his environment.

Why fashion and gossip can feel like matters of life and death.

2008-07-19T20:02:00.040+02:00

If you look at the magazine stands all over the world, you'll see that the women's section is dominated by fashion and gossip. Why do women find it more important then men to know about the latest fashion trends and rumours?

Maybe evolution can explain why women seem to care more about fashion and gossip than men. Find out why getting the latest handbag, dress, shoes and rumour really is a matter of life and death..

Humans evolved over millions of years as hunter-gatherers in an environment much like the African savannah. The people that we see around us today are those whose ancestors did well in that environment. The men going out hunting. The women taking care of the children and gathering fruits and vegetables. At first glance there doesn’t seem to be much skill involved in gathering. It is mostly a matter of time and luck. You walk and walk and every now and then you bump into that tree full of fruits or those plants with the roots just ripe to be eaten.

When you find something, you get your stomach and your arms full and go home. Sometimes you may find just enough for you and your family, but often there is quite a bit more than you need. So you walk home, not only with the fruits or vegetables, but also with some valuable information. The information that can let others know where they can find that fruiting tree or those ripe vegetables. In a world where the sugar of ripe fruits is at a premium, that really is valuable information.

But there is a time constraint on the value of that information. Many animals are after the sugars in the fruits, they could be gone in days or even hours. And even if they are not taken, the fruits will soon fall to the ground and rot. So if you want to make the most of that information, you need to move quickly, it won't last. When you come back to the group, who will you tell? Will you share it with everyone, just shout it out? In your best interest, you should give it to the person that will return the favour some other day. So that when they find something, they will let you know and you can go and get your share for your family another time.

So who should you let in on your little secret. How about that friendly, but somewhat lonely neighbour? As much as she tries, the neighbour isn’t more likely than you to find a valuable store of goods. Your best bet is the woman that always seems to be in on the latest finds. You want to maintain a close relationship with her. Telling her about your find will surely make her happy to know you. And she will be able to tell you when there is another great find some time later. But you cannot count on her always returning the favour unless you still seem to be of good use to her in the future. She will let you in on what she knows as long as she thinks you will be able to return the favour one day.

This is why it is important as a woman to show you are in on the latest finds. That you belong to the inner circle where news seems to arrive first. Anything you can show to signal this privileged position increases the likelihood that others will let you in on their next bit of hot information. It signals that you are worth sharing information with, because you will be able to return the favour some other time. That is what gets you that steady stream of valuable fruits and vegetables for yourself and your children, and prevents you from having to wander the fields forever.

The gathering of wild fruits and vegetables is a highly information intensive occupation. It requires a good information network and an ability to show it off. Gossip is one way to show you are quick to be informed. Fashion is a more recent signal between women showing who is an insider worthy of your secrets, and who is not. Of course there can be real value in clothes that make you look good, or a rumour that shows someone can't be trusted. But there is a separate female interest in being the first to spread the information. Like cars could not have been a status symbol between men before 1900, using clothes and accessories as a signal may only have become possible since the introduction of mass production. But the need to signal is there, how it is done depends on the most efficient method available.

When there is value in spreading the word about the latest finds, actually discovering them is a solution to compensate for the lack of information. So women of a lower social status may be seen shopping longer, in search of small treasures. When it comes to rumours, discoveries are made by constantly watching social interactions in search for novelties. The chewing gum alternative in today's world is watching soaps on television. Every little insight you gain gives a buzz, as if you've just secured some more credit in the information market. And if you can't find the latest, you can always make something up, but don't get caught!

Gathering isn't as simple as it seems, it takes a good social information network and the ability to show you have it. Gossip and fashion are signals used to show off the gatherer's position in the network. Women still dedicate a lot of effort to keeping up with the latest information, because once it really was a matter of life and death..

Why we laugh together and can't get enough of TV.

2008-07-10T12:01:00.056+02:00

Ever wondered why laughing is such a social activity? And why we watch so much TV, even when it doesn't seem to give us much in return?

Maybe it is our social brain that makes us do it. A brain that never expected to be fooled by electronics..

Imagine you are a solitary animal and you are turning into a social one. Now being nice to your kin is easy because that benefits your own genes. As long as the cost to your fitness is less than their benefit times the degree of relatedness, no problem.

But when it comes to living in a large, complex and less related group you need a different set of rules. There are a lot of prisoner dilemmas that need to be solved. You don't get to benefit from group living unless you are geared towards the optimal solution where you take the effect of your actions on your neighbours into consideration. Evolution solved that with social emotions, like shame, pride, envy, respect, indignity, embarrassment etc. They all work to get you to choose the seemingly suboptimal choice, but the one that in the long run works best for you in the group.

In every society, there are the unwritten rules that determine when you should be ashamed of yourself, or when you can take pride in your actions. The problem with these systems of social rules is that they can vary a lot in their absolute form. In some societies it is acceptable to kill the wife that betrays you and hack off the hands of a thief. In others, a murderer can get a slap on the wrist and thieves are just told off. There can be large differences over time and from group to group in the applicability of the social emotions we are all equipped with.

The thing to understand is that you can function just fine under all systems, as long as you are in tune with the going morals. So you can't be taken advantage of and you won't make costly social blunders. It is this staying in tune that takes constant calibration of your social sensitivities with those of the others. The brain's best mechanism to achieve this is to have you listen to stories about all kinds of social situations, while at the same time carefully taking into account your environment's reactions. Are people laughing out loud? Are they sounding outrage? Empathy? The kind and the strength of the reactions around you is the valuable information your brain needs to get you to behave in tune with your group.

So evolution has equipped you with a liking for these social narratives. Not because those stories are so special, but because your brain needs you to calibrate your moral sensitivities to those of your group. The others laugh? You feel like laughing. The others are upset? You start to feel upset. Slowly but surely the brain nudges your position closer to the others and the group's outbursts of approval and disapproval synchronize.

Stories with the kind of humor that manages to walk the fine line between funny and rude are valuable. The group's reactions let you know exactly where the social boundaries are. But you can see why watching sitcoms on TV without the included laughter doesn't work. Not only can't you laugh with the others, you actually get the message that what you are seeing shouldn't be deemed funny because nobody else is laughing.

Laughing, cheering and booing are all useful social signals, they wouldn't be so loud if they weren't. You don't send out deliberate signals if they don't benefit you in some way. They are used to get you in tune with the group, and the group in tune with you. Because when it comes to social morals, it doesn't pay to be different.

In the modern world we automated the stone-age storyteller in the middle of the group, into the TV-set we mostly watch on our own. People can spend hours watching almost the same storyline in soaps, comedy and drama again and again. It's their social brain that makes them do it. But without the ever changing vocal reactions of our group, it may have become a waste of time. The brain never anticipated being fooled by electronics.