Tribal war drove human evolution of aggression
September 9, 2008 By Lisa ZygaWars are costly in terms of lives and resources – so why have we fought them throughout human history? In modern times, states may fight wars for a number of complex reasons. But in the past, most tribal wars were fought for the most basic resources: goods, territory, and women.
These reproduction-enhancing resources prompted our ancestors to fight in order to pass down their family genes. With war as a driving force for survival, an interesting pattern occurred, according to a new study. People with certain warrior-like traits were more likely to engage in and win wars, and then passed their warrior genes down to their children, which – on an evolutionary timescale – made their tribe even more warrior-like. In short, humans seem to have become more aggressive over time due to war’s essential benefits.
In their study, Stanford University scientists Laurent Lehmann and Marcus Feldman have presented a model showing that aggressive traits in males may have evolved as an adaptation to limited reproductive resources. Because tribal war serves as a method for appropriating territory and women, war may have driven the evolution of these traits.
The scientists use the term “belligerence” to refer to a trait that increases the probability that the person’s tribe will attack another tribe. Likewise, “bravery” refers to a trait that increases the probability that the person’s tribe will win a war, whether they have attacked or are being attacked.
Lehmann and Feldman demonstrate in their model that belligerence and bravery continue to genetically evolve through the male line. When one tribe conquers another, males in the conquering group mate with females in the conquered group, and pass the warrior traits to their male offspring.
“Suppose that for some reason or another each individual in a population is committed through genetic or cultural influence to go to war with probability 0.5,” Lehmann told PhysOrg.com. “Now in one group, an individual appears that is willing to go to war with probability 0.6, which, statistically, will increase his group to go to war. The genes or cultural variants causing individuals to go to war with probability 0.6 may then invade the population (because their bearer and their group members will produce more offspring and send more genetic or cultural variants in the next generation than individuals expressing the probability 0.5 to go war, and on average they will transmit to their offspring the tendency 0.6 to go to war), but this will take several generations, especially if belligerence or bravery is genetically determined.
“Once the probability 0.6 is fixed in the population, a value of 0.7 is more likely to invade than a decrease to 0.5. So it is true that there is gradual, step-by-step evolutionary process causing the increment in the tendency to go to war, but this might take a long time. Our model is a bit less idealized than this, but it works approximately like that.”
However, as you might expect, there is a downside to belligerence and bravery. While both these traits offer advantages during war for a tribe, both traits are also considered high-risk social behaviors. An individual possessing the traits has a greater chance of dying, which means the tribe not only loses a warrior, but the death also opens a spot for another male to appropriate the first male’s reproduction-enhancing resources.
This trade-off leads to another question: if an individual himself does not benefit from belligerence and bravery, but only his tribe, why would humans evolve this altruistic trait? The scientists explain that the answer is kinship: a human will take the risk of dying for close relatives since they carry very similar genetic material, and will pass that genetic material on for him.
“The mathematical analysis in fact shows that the selective pressure on belligerence and bravery is substantially driven by the benefits of conquest that accrue on the relatives of the belligerent and/or brave males within their group, showing that kinship ties shape warfare in our model,” Lehmann said. “Evolutionary biologists refers to this as ‘indirect’ transmission of genes because the individual expressing the trait does not reproduce (it's in fact costly for him), but other individuals from the group who survive may indirectly benefit from the behavior of the possibly dead brave male.”
Lehmann added that the genetic relatedness concept stems from the late Bill Hamilton of Oxford University, one of the greatest evolutionary biologists of the 20th century. Prior to Hamilton, the British geneticist J. B. S Haldane also hit upon the idea in a famous anecdote. When asked by a friend at a pub whether he would risk his life to save a drowning man, Haldane scribbled some notes on a napkin and answered, “No, but I would do it for two brothers or eight cousins."
The same idea holds true for the altruistic traits of belligerence and bravery, but Lehmann and Feldman were surprised to find just how large a group could show the kinship connection.
“[The greatest significance of this study is] showing that the selective pressure on belligerence and bravery may remain substantial even in groups of large size (approximately 50 males and 50 females),” Lehmann said. “This is interesting because it is usually assumed that individually costly, altruistic traits (of which belligerence and bravery are only particular examples) would only be able to evolve in very small-sized groups, like the nuclear family or something only slightly bigger. The demographics behind warfare may explain the evolution of altruism in larger groups than have usually been assumed in more standard biological scenarios aimed at understanding the evolution of altruism.”
Among other interesting results of the model is the finding that bravery is even more highly desired than belligerence, since bravery has advantages when tribes are on both the offensive and defensive sides. On a different note, even though the model describes genetic inheritance, the scientists say that these traits could also be inherited culturally (through nurture rather than nature).
Today’s modern wars between large states, as opposed to tribal wars, don’t follow the same model. Rather, one of the most common explanations is that modern wars are fought when the benefits outweigh the costs, in a fairly rational way. But do the results of this study, showing that we are all offspring of conquerors, suggest an underlying primitive explanation for why we fight “rational” modern wars? Though it may be an intriguing idea, Lehmann doesn’t think so.
“I don't think that our study helps in one way or another to understand war between states, but there are many interesting and relevant theories for understanding such wars that have been developed by economists and political scientists,” he said.
More information: Lehmann, Laurent and Feldman, Marcus W. “War and the evolution of belligerence and bravery.” Proceedings of The Royal Society B. doi:10.1098/rspb.2008.0842.
Copyright 2008 PhysOrg.com.
All rights reserved. This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of PhysOrg.com.
Oct 21, 2009 |
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evolution of altruism? jajajaja jajejejeje
If you look at societies not much has changed, they've simply grown in size.
So instead of having a small tribe of my surname or the location we're from, I have a huge tribe of "Americans." So instead of tribalism you have nationalism. Same thing, larger group.
And as for your global warming, lol, prove it's man made before you say it's our fault.
Chimp Olympics! (Actually I don't think that chimps fight as much against one another.)
http://www.world-...rfrm.htm
Whoever can most efficiently consume energy is going to win. The key, of course (and this is where the wars are) is that to consume energy, you have to control it.
Does it really matter if its our fault or not? I think the consequences are enough reason for us to start taking action.
So the IPCC is a religious organization now.
I thought they were scientists, you know, the people who turn their hypothesis into a theory and then into a law through science.
And as for proving it isn't CO2 maximum entrapment is limited to 0.0038ppm which is far less than the 280 ppm we live in only 0.03% of which is man made.
Actually, the only species other than homo-sapiens that wages war against other groups of the same species is the chimp.
What do those numbers represent? Can you provide source?
Do the math. CO2 is at max absorption of IR within 10 meters of it's source at a concentration of 280 ppm.
The distance from the earth to the tropopause is 16km at the equator and about 8km at the poles.
Since CO2 has a logarithmic relationship you can double the amount of CO2 and it will only absorb 50% more IR per concentration. Conversely if you half the amount of CO2 it will travel twice the distance before being absorbed.
So for IR to be able to orginate at the earth and escape the troposphere without being absorbed, the concentration at the equator would have to be less than 0.0038 ppm. At the poles less than 0.0076ppm.
You get these numbers by dividing the amout of CO2 by 2 until you reach a distance of absorption of 16km at the equator or 8km at the poles. Since human kind can only be attributed with 0.3% of the total CO2 in the environment then removing the 0.3% will reduce absorption by about 3 dm, that's it.
That's not really true, most apes do it as well, some dogs, and some fish will also wage wars to some extent.
You said 'do the math'. Would you care to mention what exactly are the physical tehories and mathematical equations behind your assertion? I have hard time understanding what you mean, but that may well be because english is not my first language.
According to satellite observations of outgoing IR radiation, the greenhouse effect has intensified: http://archives.c...dex.html
As for this news, I would assume environmental conditions have a marked effect on how much the belligerence and bravery of an individual benefit a group. In a harsh environment war drains a lot more resources than in a favorable environment.
What exactly are the ape (non-chimp), dog and fish species/breeds that wage war? I would like to see descriptions of these wars in addition to receiving examples of the species.
Nature is incredibly vicious and HAS NO SENSE OF MORALITY. It doesn't make any judgements, or hold any war crimes trials, or care about genocide. It simply is what it is.
Gmurphy: CO2 levels in the 70's were 260ppm. CO2 levels now are 280ppm. That is not 1/3. Man made CO2 has a 1/3 of a percent contribution to the total atmostpheric co2. 99.7 % of CO2 is created by rotting plant matter, volcanic eruption, and other normal Earth processes.
Rute: The math above follows the laws of IR absorption as measured by the UN IPCC and confirmed by infrared spectometrists according to the laws of IR energy absorption lain out in Chemistry, Spectomotry, and Physics.
Also your article doesn't measure the whole equation. If the Earth's visible light albedo rose then you would see a marked decrease in IR due to the fact it is not being produced. You're also discounting the fact that CO2 doesn't absorb IR across all ranges, only across 3 small increments. So your article is not in-depth enough to prove anything as it doesn't find a cause for the lack of IR detected. It creates the supposition that it must be CO2 and it must be man-made with no underlying reason. That makes it opinion, not fact.
Rute again: Every territorial pack animal in existance wages war agaist it's competition. All predators do for the most part as long as the cost is not high enough to preclude the fight.
Fighting the CO2 global warming fight is a losing battle for you guys, the science doesn't support CO2 as the perpetrator of AGW.
Now do I believe that the planet is warming, yes I do. Do I believe humanity is responsible, no I don't. We're too small to make that great a change on an environment that has endured far greater stress and duress than the human race could create.
You don't seem to understand that all of the fossil CO2 humans produce is outside of the natural cycle, which means it is the only non-geological process which increases the CO2 in the biosphere. Yes, rotting plants exhale CO2, but without that process we wouldn't have practically any CO2 in the atmosphere, because all of the plant CO2 would form deposits in the ground.
Volcanos produce fossil CO2, but there haven't been enough large eruptions lately which would explain the steady cumulation of CO2 in the atmosphere. Actually there have been relatively few volcanic eruptions in the 20th century.
You haven't shown any math yet, just some separate numbers. Tell me about the mathematic formula of a theory which you base your assertions on.
That's not true. The article clearly states that the decrease of IR radiation has specifically been observed on the wavelengths which the anthropogenic greenhouse gases absorb it.
From the article: "An Imperial College of London team looked at readings of infrared light from the Earth's surface, specifically in the wavelengths absorbed by greenhouse gases such as carbon dioxide, methane and ozone."
I repeat my question: "What exactly are the ape (non-chimp), dog and fish species/breeds that wage war? I would like to see descriptions of these wars in addition to receiving examples of the species."
Considering past CO2 concentration levels were around 512ppm or greater in recorded history and Co2 levels have breached the 1000ppm mark with no ill effects to the environment, present CO2 levels don't alarm me what so ever.
You're joking right? http://www.infopl...388.html
Ok so I'll do the math for you then:
280 ppm = 10 m/absorption.
The relation ship between CO2 levels and absorption is logarithmic so as you double co2, it reduces distance by 50%. Conversely if you cut CO2 in half you double the distance of absorption saturation. So cut co2 in half
140ppm=20m
70ppm=40m
35ppm=80m
17.5ppm=160m
continue the trend until you reach 16km and that is the CO2ppm you need at the equator for IR to escape the tropopause without being absorbed.
Right, but it doesn't include past cloud cover, past landscape albedo, concentration increase, concentration increase of the supposed AGW components and the relationship to the IR.
They are observations without experimentation. Our atmosphere is far more complex that "Hey we see more IR it must be AGW."
Where did they measure it, from inside the atmosphere? From a satellite located on the exterior of the tropopause? What was the ionizing solar activity like during the measurements? There is no substance to their statement.
Austrailian Dingos: combat for territory. Lions: pack vss pack combat for territory and mating rights, Grey Wolves: kill all competition smaller than a bear cub when encountered and do not eat their enemies. Gorillas: mating rights and territory as well as food and water sources. All Betta species and subspecies, Oscars and other Cichilids, Catfish, All species of eel, how many more do you want?
http://www.infopl...388.html
and that's just the past decade or so.
You don't understand the issue, yes the level of CO2 is such that all IR radiation emitted on Earth's surface is absorbed by CO2 in the atmosphere before it reaches the space.
Thats true but that doesn't mean that increasing CO2 does not increase Earth's temperature.
The mechanism of greenhouse effect of CO2 is that increasing CO2 concentration leads to infrared energy (=heat, emitted by black body radiation of objects on Earth's surface) being absorbed closer to Earth's surface, and the closer absorption occurs the longer (more cycles of reemission and absorption) it will take that energy to escape into space.
The longer it takes, the less effective Earth's cooling and the higher its temperature.
Seriously if you want to debunk something make sure you first understand it, otherwise you only spread disinformation and theres too much of that already.
Here it is explained in more detail:
http://brneurosci.org/co2.html
Not true. From the Volcano Hazards Program of US Geological Survey:
"Scientists have calculated that volcanoes emit between about 130-230 million tonnes (145-255 million tons) of CO2 into the atmosphere every year (Gerlach, 1999, 1991). This estimate includes both subaerial and submarine volcanoes, about in equal amounts. Emissions of CO2 by human activities, including fossil fuel burning, cement production, and gas flaring, amount to about 27 billion tonnes per year (30 billion tons) [ ( Marland, et al., 2006) - The reference gives the amount of released carbon (C), rather than CO2, through 2003.]. Human activities release more than 130 times the amount of CO2 emitted by volcanoes--the equivalent of more than 8,000 additional volcanoes like Kilauea (Kilauea emits about 3.3 million tonnes/year)! (Gerlach et. al., 2002)"
http://volcanoes....ndex.php
Where was this measurement made? In your car's exhaust pipe?
No I'm not. As the US Geological Survey page points out, there would need to be about 8000 additional Kilauea volcanoes to produce the amount of CO2 humans do per year.
I repeat my question: what is the physical theory and exact formula that you use to make that assertion?
Are you saying that changes in ground use and cloud cover would produce similar changes in the wavelength of outgoing IR radiation as increased levels of CO2, methane and ozone?
That's not what they say at all. The peak IR absorption wavelengths of CO2 have been measured in laboratory.
War essentially means killing members of the same species in large amounts. Would you now give detailed examples (observations) of this happening with your aforementioned species?
http://volcanoes....ndex.php
(-> effects)
Do you think chimps make war on each other? If you do then your definition is flawed...they don't kill each other in large numbers with respect to us. This issue by it's very nature is relative, thus you're treading very closely to a strawman argument here.
[09:50] SR: so you're a proponent of intelligent design? ;-)
[09:50] VS: how would these fools' thesis is any way describe the tribe(?s) that have accurately mapped out a star we cannot see with our naked eye
[09:56] VS: even framing an argument in terms of intelligent design is a paradigm trap
[10:07] SR: perhaps you missed the emoticon?
[10:08] VS: ok...
[10:08] VS: still... this piece is being published by a website calling themselves PhysOrg??? blah.
Article: http://www.jhguid..._id=1551
That pretty much fits the definition I have of animal war, thanks. However, I haven't heard of dingos, fishes or gorillas behaving similarily (has to do with the original claim of Velanarris). That is not to claim they don't 'wage war', it's just that I'd like to see some documented cases of it.
Considering the main mechanism of heat loss for the planet is convection and precipitation, make sure you understand all aspects of the system before you speak on the subject.
Look up what the past CO2 levels were according to geology. They are considered the gold standard for actual CO2 measurement.
Now you're being silly. Chemistry and physics determine the saturation levels and Earth observation presents the distance.
Absolutely. If the sun's rays aren't able to contact the Earth then the "black body" radiation output will vary greatly. IR will have huge difference between winter and summer in areas that receive heavy cloud or snow cover.
Pertinence to my statement?
That's a poor definition.
War is classically defined as a contest of force between 2 or more groups. Typically over resources or territory. Two groups of 5 would constitute two tribes. If they engage in skirmishes to control territory or mating rights that is a war, which all of the listed species engage in regularly.
As for documented cases, flip on Animal Planet.
Haha! First rule of holes: If you are in one stop digging!
First it was you who brought the argument with IR radiation and absorption, I only pointed out that you misunderstood it.
Second, now you made even more obvious mistake - a planet can never lose heat by precipitation or convection! A planet is surrounded by vacuum and neither of this mechanisms operates in vacuum!
Precipitation and convection can only redistribute heat ON the planet.
http://en.wikiped...orology)
http://en.wikiped...nvection
The only means of transporting heat out of the planet is by radiation!
Stop arguing for the sake of arguing and before you invoke yet another phenomena at least google it first and read its wiki page - you can learn a lot.
Otherwise this is a very interesting article. Particularly for a professional warrior such as myself and the millions of past and present combat servicemen around the world. If this article somehow pisses you off, you probably spend much of your intellect rationalizing your intuitive values. So, get a life.
and you were incorrect. IR will escape at the same rate regardless of opacity due to a few factors.
One of which is, the heated gas will have to find a lower energy environment in order to re-radiate, which means it must rise through convection or being displaced by condensing water vapor, meaning....
As the gas rises and re-radiates the energy it will approach the tropopause meaning the excess energy will escape to the stratosphere and ionosphere where it will...
Highly charge the particles of the ionosphere to the point that they reach escape velocity or exchange energy with the low powered low weight particles left behind by solar wind collision.
Or mass displacement of ionized gas, which is ever present in the near earth atmosphere.
Because wikipedia is super accurate.
By the way, excess heat in the system would create more cloud cover and in turn lower the Earth's albedo in addition to completely crowding out CO2's absorption bands.
Even if that were true, the rest is not outside of the natural cycle!
The proportion of carbon isotopes 12C and 13C are rising in the atmosphere because of the fossil carbon emissions. Rotting leaves can't be responsible of that. Saprotrophs just recycle the carbon available in the biosphere. They are unable to add or substract carbon from the mantle and abiotic crust.
Look up what the past CO2 levels were according to geology. They are considered the gold standard for actual CO2 measurement.
There have not been 512 ppm concentrations globally in the recorded history. The prehistorical geological reconstructions of CO2 concentration are another matter.
That there means you have no clue of the physical formulae behind greenhouse effect.
To make the difference of the biological processes vs. fossil fuel burning clear: the former can NOT make CO2 concentration in the atmosphere go up, but the latter can and does so.
You are incredibly ignorant of the processes involved and are just spewing the AGW rhetoric you've been fed by the miscellaneous publications seeking financial gain for said publishing.
You realize during their night cycle plants release CO2 as well? Or that rotting plant matter releases c12 c13 and c14?
Or prefacing your statements that there have not been concentrations of CO2 at 512ppm or higher in recorded history, of course there haven't been "known" concentrations, we didn't start measuring it until the 60's. Which means we have 48 years of data, some of which is highly questionable. We don't know what is causing global warming, we don't know if it's man made, we don't know if this is part of the natural cycles we've seen documented in the past, and we certainly shouldn't be doing anything without a knowledge of whether we're helping or hurting the situation by interfering.
That you cannot deny logically.
I'm not basing my facts on "AGW rhetoric". I just happen to know some basic things of Earth science. As I already mentioned, the biological processes are unable to add or substract CO2 from the mantle and abiotic crust (nearly free of 14C). Are you denying that?
Yes, but the CO2 balance of plants is negative, that is, they take up more CO2 than they release into the atmosphere.
Of course, but rotting plant material is unable to change the relative amounts of the mentioned isotopes. You need CO2 which hasn't been a part of the biosphere for thousands of years to make the 12C/13C concentration rise relative to 14C as observed. That's because 14C, which is formed in the upper atmosphere, is an unstable isotope and decays over the course of thousands of years and is therefore not present in high amounts in the fossil fuel reserves and Earth's mantle.
Then why did you say there have been?
What kind of evidence would convince you that global warming is mostly man made?
Their results are bullshit.
One of the oldest surviving cultures on earth is the Kalahari Bushmen.
Theirs is a most non-aggressive culture.
Then you look at the stone age New Guinea natives. Some of these are still cannabalistic.
Most of their "wars" are more ritual than real.
They will put on a very noisy and showy performance and the most impressive wins the less impressive yields.
Occasionally a few are killed. If it was a real war as we "civilised" societies know war there would be hundreds of dead.
Their wars are more like the confrontations between animals for superiority. Rarely is an opponent seriously injured and even less often is an opponent killed.
The animal or what we term the uncivilised way relies more on posturing and or a show of force or power and far less on actual killing.
We do not appear to acquire the lust for killing until we become "civilised".
Leaving thousands or even millions dead is a measure of our degree of civilisation, the more we kill the more advanced we are.
These half-witted academics should stop making excuses for our barbarism.
In what we term as primitive societies and animal groupings we find that adults protect the young, yet we have to protect our young from our own species.
I think Lehmann and Feldman need to rethink their whole approach and to reassess their starting values.
Of course there are, as there always will be the odd exception to this norm, i.e. Siamese Fighting Fish and of course Modern Civilised Man, i.e. Pol Pot, Adolph Hitler, Churchill, Mugabe, Stalin, Mao, and the list goes on. Apart from the Siamese Fighting Fish all of these others seem to be us.
Hard data and research.
Patently false, Grey Wolf territorial wars leave the population down by 44% in yellowstone park. This population of wolves is perhaps the best studied in the world.
I challenge you to produce an example of modern human warfare where the end result was the death of 44% of the population of the opposing sides.
Obviously you've never heard the news of the violence in Africa, the Middle East, Imperial Japan (just one of many historical examples), or basically EVERY (including North America) place on Earth where there are people.