|
|
| Line 1: |
Line 1: |
| [[File:Todd Huffman - Lattice (by).jpg|thumb|upright=1.3|The co-operative behaviour of [[social insects]] like the honey bee can be explained by kin selection.]]
| | == each division has its own heavy fire spirit == |
| '''Kin selection''' is the [[evolution]]ary strategy that favours the reproductive success of an organism's relatives, even at a cost to the organism's own survival and reproduction. '''Kin altruism''' is [[Altruism in animals|altruistic behaviour]] whose evolution is driven by kin selection. Kin selection is an instance of [[inclusive fitness]], which combines the number of offspring produced with the number an individual can produce by supporting others, such as siblings.
| |
|
| |
|
| Charles Darwin discussed the concept of kin selection in his 1859 book, ''[[The Origin of Species]]'', where he reflected on the puzzle of sterile social insects, such as [[honey bees]], which leave reproduction to their sisters, arguing that a selection benefit to related organisms (the same "stock") would allow the evolution of a trait that confers the benefit but destroys an individual at the same time. [[R.A. Fisher]] in 1930 and [[J.B.S. Haldane]] in 1932 set out the mathematics of kin selection, with Haldane famously joking that he would willingly die for two brothers or eight cousins. In 1964, [[W.D. Hamilton]] popularized the concept and the major advance in the mathematical treatment of the phenomenon by [[George R. Price]] which has become known as "Hamilton's rule". In the same year [[John Maynard Smith]] used the actual term kin selection for the first time.
| | On that side of the bones, 一枚 white 'color' is satisfied that every now and then the sky, fall into their hands, flexor of a bomb, a roll of pale 'color' of the [http://www.ispsc.edu.ph/nav/japandi/casio-rakuten-6.html 腕時計 メンズ casio] reel is present in its front, above the reel, drawing some Quintana beast birds braved flames.<br><br>'This is the year of the famous old [http://www.ispsc.edu.ph/nav/japandi/casio-rakuten-3.html カシオ gps 時計] lady fighting skills,' five from the Fire, 'Oh, that's fighting skills are also some wrong, it should be said that the law must [http://www.ispsc.edu.ph/nav/japandi/casio-rakuten-10.html casio 腕時計 データバンク] control the fire.' Venerable Skyfire will then reel [http://www.ispsc.edu.ph/nav/japandi/casio-rakuten-8.html カシオ 掛け時計] thrown Xiao Yan, said: 'As long as you can help the old lady, then this thing will be yours, if you doubt the sincerity of the old lady, you can take the reel, was found to be no problem, then help me to repair the soul too late.'<br><br>cautiously took the reel, Xiao Yan hesitated a moment, just cautious gradually spread.<br><br>'five from Fire, fire control method formula, France is divided into five weight, according to the zoomorphic and identified, wolves, leopards, lions, tigers, Jiao, each division has its own heavy [http://www.ispsc.edu.ph/nav/japandi/casio-rakuten-13.html 時計 カシオ] fire spirit, France tactic Dacheng, five animals gathered , |
| | 相关的主题文章： |
| | <ul> |
| | |
| | <li>[http://www.nnzqm.com/forum.php?mod=viewthread&tid=686610 http://www.nnzqm.com/forum.php?mod=viewthread&tid=686610]</li> |
| | |
| | <li>[http://www.pyjiazhuang.cn/forum.php?mod=viewthread&tid=44024 http://www.pyjiazhuang.cn/forum.php?mod=viewthread&tid=44024]</li> |
| | |
| | <li>[http://www.nwcommunities.org/author-diana-leafe-christian-to-present-talk-at-east-west-bookshop-tea-garden-august-21-2013/comment-page-/#comment- http://www.nwcommunities.org/author-diana-leafe-christian-to-present-talk-at-east-west-bookshop-tea-garden-august-21-2013/comment-page-/#comment-]</li> |
| | |
| | </ul> |
|
| |
|
| According to Hamilton's rule, kin selection causes genes to increase in frequency when the genetic relatedness of a recipient to an actor multiplied by the benefit to the recipient is greater than the reproductive cost to the actor. The rule is difficult to test but was verified experimentally in 2010 by observing adoption of orphans by surrogate mothers in a wild [[Tamiasciurus hudsonicus|red squirrel]] population. Hamilton proposed two mechanisms for kin selection: [[kin recognition]], where individuals are able to identify their relatives, and viscous populations, where dispersal is rare enough for populations to be closely related. The viscous population mechanism makes kin selection and social cooperation possible in the absence of kin recognition. [[Nurture kinship]], the treatment of individuals as kin when they live together, is sufficient for kin selection, given reasonable assumptions about dispersal rates. Kin selection is not the same thing as [[group selection]], where [[natural selection]] acts on the group as a whole.
| | == his eyes also promised some more excitement' color. ' == |
|
| |
|
| In humans, altruism is more likely and on a larger scale with kin than with unrelated individuals; for example, humans give presents according to how closely related they are to the recipient. In other species, [[vervet monkey]]s use [[allomothering]], where related females such as older sisters or grandmothers often care for young, according to their relatedness. The social shrimp ''[[Synalpheus regalis]]'' protects juveniles within highly related colonies.
| | Thing! 'Words to the end, on the face of the emergence of a large Presbyterian touch ruddy, his eyes also [http://www.ispsc.edu.ph/nav/japandi/casio-rakuten-12.html カシオ 腕時計 ソーラー] promised some more excitement' color. '<br><br>hear this big elders has not been determined, Xiao Yan and Medusa are a heavy sigh of relief, perhaps this is [http://www.ispsc.edu.ph/nav/japandi/casio-rakuten-14.html カシオ腕時計 メンズ] just an accident<br><br>'Whether this is true, you have to remember, perhaps later to be extra careful to wait a period of time, that is, your body is able to determine what the reason.' Qiaode It looks like Medusa, a large Presbyterian brow wrinkled, Chen Sheng said.<br><br>'this time is how long?' Xiao Yan stem asked with a smile.<br><br>'snake Terran Unlike humans, especially blood or Medusa, if indeed pregnant, time will not short, three to five years is the normal things.' great elders faint.<br><br>Wen Yan, Xiao Yan mind [http://www.ispsc.edu.ph/nav/japandi/casio-rakuten-15.html カシオ ソーラー 腕時計] again relieved, okay, if this two-month [http://www.ispsc.edu.ph/nav/japandi/casio-rakuten-4.html カシオ 腕時計 バンド] period to [http://www.ispsc.edu.ph/nav/japandi/casio-rakuten-14.html カシオ 腕時計 ソーラー 電波] determine the case, then he really jumped from the wall |
| | 相关的主题文章： |
| | <ul> |
| | |
| | <li>[http://www.xinzhinang.com.cn/plus/feedback.php?aid=167 http://www.xinzhinang.com.cn/plus/feedback.php?aid=167]</li> |
| | |
| | <li>[http://commonnet.no-ip.biz/mediawiki/index.php/User:Xvydprnbiw#after_a_moment http://commonnet.no-ip.biz/mediawiki/index.php/User:Xvydprnbiw#after_a_moment]</li> |
| | |
| | <li>[http://jirostyle.com/bbs/index.cgi http://jirostyle.com/bbs/index.cgi]</li> |
| | |
| | </ul> |
|
| |
|
| ==Historical overview== | | == vague hoarse voice == |
|
| |
|
| [[Charles Darwin]] was the first to discuss the concept of kin selection. In ''The Origin of Species'', he wrote clearly about the conundrum represented by [[altruistic]] sterile [[social insects]] that | | Under its frustration when it will exit so state, that is about to dissipate depleted grain dust pregnant spirit within my mind, but it is suddenly a burst of intense light, etc. In this [http://www.ispsc.edu.ph/nav/japandi/casio-rakuten-0.html カシオ電波ソーラー腕時計] light, even even Xiao Yan soul are all feeling a sharp pain in the emergence.<br><br>pain gradually fade, [http://www.ispsc.edu.ph/nav/japandi/casio-rakuten-7.html カシオソーラー時計] in some panic among Xiao Yan, at the outbreak of that light, [http://www.ispsc.edu.ph/nav/japandi/casio-rakuten-8.html casio 腕時計 スタンダード] it was a faint sound came between extremely low blurred the old 'Yin'<br><br>'very soul [http://www.ispsc.edu.ph/nav/japandi/casio-rakuten-2.html カシオの時計] of ... close ... Carolina Ling Ling Shou days forging Soul'<br><br>vague hoarse voice, whispering in XiaoYan minds back to 'swing', like Fine resounded like to make people kind of get a [http://www.ispsc.edu.ph/nav/japandi/casio-rakuten-14.html casio 腕時計 phys] sense of trance.<br>Trance does not make sense<br>Xiao Yan therefore absence, and that the sound of the minds of old, although vague, but it is possible he jotted down a lot, and this old sound, in retrospect it three times After that is thoroughly dissipated away<br><br>room |
| | 相关的主题文章： |
| | <ul> |
| | |
| | <li>[http://skwlkr.s18.23dns.net/forum/forum.php?mod=viewthread&tid=594324 http://skwlkr.s18.23dns.net/forum/forum.php?mod=viewthread&tid=594324]</li> |
| | |
| | <li>[http://www.aiyingfang.cn/bbs/showtopic-904878.aspx http://www.aiyingfang.cn/bbs/showtopic-904878.aspx]</li> |
| | |
| | <li>[http://www.webngardha.blogdehi.com/shockwave/download/download.cgi http://www.webngardha.blogdehi.com/shockwave/download/download.cgi]</li> |
| | |
| | </ul> |
|
| |
|
| {{quote|This difficulty, though appearing insuperable, is lessened, or, as I believe, disappears, when it is remembered that selection may be applied to the family, as well as to the individual, and may thus gain the desired end. Breeders of cattle wish the flesh and fat to be well marbled together. An animal thus characterized has been slaughtered, but the breeder has gone with confidence to the same stock and has succeeded.|Darwin<ref>{{cite news |url= http://www.classicreader.com/book/107/59/}}</ref>}}
| | == wooden box open == |
|
| |
|
| In this passage "the family" and "stock" stand for a kin group. These passages and others by Darwin about "kin selection" are highlighted in [[Douglas J. Futuyma|D.J. Futuyma's]] textbook of reference ''Evolutionary Biology''<ref>{{cite book |title=Evolutionary Biology 3rd Ed |last=Futuyma |first=Douglas J. |authorlink= |coauthors= |year=1998 |publisher=Sinauer Associates Inc |location=Sunderland, Massachusetts USA |isbn=0-87893-189-9 |page=595|pages= |url= }}</ref> and in[[ E. O. Wilson]]'s ''[[Sociobiology: The New Synthesis|Sociobiology]]''.<ref>{{cite book |title=Sociobiology: The New Synthesis 25th Ed |last=Wilson |first=Edward E. |authorlink= |coauthors= |year=2000 |publisher=The Belknap Press of Harvard University Press |location=Cambridge, Massachusetts USA |isbn= 978-0-674-00089-6 |page=|pages=117–118 |url= }}</ref>
| | Smile, the two boxes, open simultaneously.<br><br>wooden box open, 'Lucy,' one [http://www.ispsc.edu.ph/nav/japandi/casio-rakuten-0.html カシオ電波ソーラー腕時計] of the two items, one is a fist-sized red 'color' round beads, the second is a gray brown 'color' of unusual bamboo.<br><br>Hsiao go far people's eyes, first brought together the egg on top of red beads, they can feel it being quite violent and contains an enormous fire is 'sexual' energy.<br><br>'This is a magic nucleus?' Xiao Yan eyes firmly fixed on the red beads While [http://www.ispsc.edu.ph/nav/japandi/casio-rakuten-8.html カシオ レディース 電波ソーラー腕時計] some less certain way, so a high level of magic nucleus, but the first time I saw him.<br><br>'ah, is indeed a magic nuclear grade, but not low, but still kind of afraid of the higher-order form of Warcraft, or difficult to have such a' color [http://www.ispsc.edu.ph/nav/japandi/casio-rakuten-13.html カシオ 腕時計 ソーラー 電波] 'and energy.'<br><br>Soviet [http://www.ispsc.edu.ph/nav/japandi/casio-rakuten-7.html casio 腕時計 説明書] Union thousands stroking his beard, his eyes passing touch alarmed, said: 'This is magic nucleus, as I guess [http://www.ispsc.edu.ph/nav/japandi/casio-rakuten-3.html 電波時計 カシオ] it should be a seven-order fire is' sexual 'magic nucleus, no |
| | | 相关的主题文章： |
| The earliest mathematically formal treatments of kin selection were by [[R.A. Fisher]] in 1930 <ref>{{cite book |title=The Genetical Theory of Natural Selection |last=Fisher |first=R. A. |authorlink= |coauthors= |year=1930 |publisher=Clarendon Press |location=Oxford |isbn= |page=159|pages= |url= }}</ref> and [[J.B.S. Haldane]] in 1932 <ref>{{cite book |title= The Causes of Evolution |last=Haldane |first=J.B.S. |authorlink= |coauthors= |year=1932 |publisher= Longmans, Green & Co |location= London |isbn= |page= |pages= |url= }}</ref> and 1955.<ref>{{cite journal |last=Haldane |first=J. B. S. |authorlink= |coauthors= |year=1955 |month= |title=Population Genetics |journal=New Biology |volume=18 |issue= |pages=34–51 |id= |url= |accessdate= |quote= }}</ref> J.B.S. Haldane fully grasped the basic quantities and considerations in kin selection, famously writing "I would lay down my life for two brothers or eight [[Cousin chart|cousins]]".<ref name="quote">{{cite book | year = 1999 | title = Psychologically Speaking: A Book of Quotations | chapter = Altruism | editor = Kevin Connolly and Margaret Martlew | pages = 10 | publisher = BPS Books | isbn = 1-85433-302-X}} (see also: [[:wikiquote:J. B. S. Haldane|Haldane's Wikiquote entry]])</ref> Haldane's remark alluded to the fact that if an individual loses its life to save two siblings, four nephews, or eight cousins, it is a "fair deal" in evolutionary terms, as siblings are on average 50% identical by descent, nephews 25%, and cousins 12.5% (in a [[diploid]] population that is randomly mating and previously [[inbred|outbred]]). But Haldane also joked that he would truly die only to save more than a single identical twin of his or more than two full siblings. In 1955 he clarified:
| | <ul> |
| | | |
| <blockquote>Let us suppose that you carry a rare gene that affects your behavior so that you jump into a flooded river and save a child, but you have one chance in ten of being drowned, while I do not possess the gene, and stand on the bank and watch the child drown. If the child's your own child or your brother or sister, there is an even chance that this child will also have this gene, so five genes will be saved in children for one lost in an adult. If you save a grandchild or a nephew, the advantage is only two and a half to one. If you only save a first cousin, the effect is very slight. If you try to save your first cousin once removed the population is more likely to lose this valuable gene than to gain it. … It is clear that genes making for conduct of this kind would only have a chance of spreading in rather small populations when most of the children were fairly near relatives of the man who risked his life.<ref>{{cite journal | last1 = Haldane | first1 = J.B.S. | authorlink = | year = 1955 | title = Population genetics | url = | journal = New Biology | volume = 18 | issue = | pages = 34–51 }}</ref></blockquote>
| | <li>[http://co.ctbu.edu.cn/forum.php?mod=viewthread&tid=892593 http://co.ctbu.edu.cn/forum.php?mod=viewthread&tid=892593]</li> |
| | | |
| [[W. D. Hamilton]], in 1963<ref>{{cite journal |last=Hamilton |first=W. D. |authorlink= |coauthors= |year=1963 |month= |title=The evolution of altruistic behavior |journal=[[American Naturalist]] |volume=97 |issue= 896|pages=354–356 |id= |url= |accessdate= |quote= |doi=10.1086/497114 }}</ref> and especially in 1964,<ref name="Hamilton 1964 1–16">{{cite journal |last=Hamilton |first=W. D. |authorlink= |coauthors= |year=1964 |month= |title=[[The Genetical Evolution of Social Behavior]] |journal=Journal of Theoretical Biology |volume=7 |issue=1 |pages=1–16 |id= |url= |accessdate= |quote= |doi=10.1016/0022-5193(64)90038-4 |pmid=5875341}}</ref> popularized the concept and the more thorough mathematical treatment given to it by [[George R. Price|George Price]].
| | <li>[http://chadayamangalam.com/cgi-bin/guestbook.cgi http://chadayamangalam.com/cgi-bin/guestbook.cgi]</li> |
| | | |
| [[John Maynard Smith]] may have coined the actual term "kin selection" in 1964:
| | <li>[http://www.otis.ne.jp/97tokiwa-topics/diary.cgi http://www.otis.ne.jp/97tokiwa-topics/diary.cgi]</li> |
| | | |
| <blockquote>These processes I will call kin selection and group selection respectively. Kin selection has been discussed by Haldane and by Hamilton. … By kin selection I mean the evolution of characteristics which favour the survival of close relatives of the affected individual, by processes which do not require any discontinuities in the population breeding structure.<ref>{{cite journal |last=Smith |first=J. M. |authorlink= |coauthors= |year=1964 |month= |title=Group Selection and Kin Selection |journal=Nature |volume=201 |issue=4924 |pages=1145–1147 |doi=10.1038/2011145a0 |url= |accessdate= |quote= }}</ref> </blockquote>
| | </ul> |
| | |
| Kin selection causes changes in [[gene]] frequency across generations, driven by interactions between related individuals. This dynamic forms the conceptual basis of the theory of [[social evolution]]. Some cases of [[evolution]] by [[natural selection]] can only be understood by considering how biological relatives influence each other's [[Fitness (biology)|fitness]]. Under natural selection, a gene encoding a [[Trait (biological)|trait]] that enhances the fitness of each individual carrying it should increase in frequency within the [[population]]; and conversely, a gene that lowers the individual fitness of its carriers should be eliminated. However, a hypothetical gene that prompts behaviour which enhances the fitness of relatives but lowers that of the individual displaying the behavior, may nonetheless increase in frequency, because relatives often carry the same gene. According to this principle, the enhanced fitness of relatives can at times more than compensate for the fitness loss incurred by the individuals displaying the behaviour, making kin selection possible. This is a special case of a more general model, "[[inclusive fitness]]". This analysis has been challenged,<ref name= NTW>[[Martin Nowak]], Corina Tarnita & [[EO Wilson]] "The evolution of eusociality" ''Nature'' '''466''' 1057–1062(26 August 2010) {{doi|10.1038/nature09205}}</ref> Wilson writing that "the foundations of the general theory of inclusive fitness based on the theory of kin selection have crumbled" <ref>{{cite book |last=Wilson |first=E.O. |year=2012 |title=The Social Conquest of Earth}}</ref> and that he now relies instead on the theory of [[eusociality]] and "gene-culture co-evolution" for the underlying mechanics of [[sociobiology]].
| |
| | |
| "Kin selection" should not be confused with "[[group selection]]" according to which a genetic trait can become prevalent within a group because it benefits the group as a whole, regardless of any benefit to individual organisms. All known forms of group selection conform to the principle that an individual behaviour can be evolutionarily successful only if the genes responsible for this behaviour conform to Hamilton's Rule, and hence, on balance and in the aggregate, benefit from the behaviour.
| |
| | |
| ==Hamilton's rule==
| |
| Formally, genes should increase in frequency when
| |
| | |
| <math>rB > C </math>
| |
| | |
| where
| |
| :''r'' = the genetic relatedness of the recipient to the actor, often defined as the probability that a gene picked randomly from each at the same [[locus (genetics)|locus]] is identical by descent.
| |
| :''B'' = the additional reproductive benefit gained by the recipient of the [[altruistic]] act,
| |
| :''C'' = the reproductive cost to the individual performing the act.
| |
| | |
| This inequality is known as '''Hamilton's rule''' after W. D. Hamilton who in 1964 published the first formal quantitative treatment of kin selection.
| |
| | |
| The [[relatedness]] parameter (r) in Hamilton's rule was introduced in 1922 by [[Sewall Wright]] as a [[coefficient of relationship]] that gives the [[probability]] that at a random [[locus (genetics)|locus]], the [[allele]]s there will be [[identical by descent]].<ref>{{cite journal | last1 = Wright | first1 = Sewall | authorlink = Sewall Wright | year = 1922 | title = Coefficients of inbreeding and relationship | url = | journal = [[American Naturalist]] | volume = 56 | issue = 645| pages = 330–338 | doi = 10.1086/279872 }}</ref> Subsequent authors, including Hamilton, sometimes reformulate this with a [[Regression analysis|regression]], which, unlike probabilities, can be negative. A regression analysis producing statistically significant negative relationships indicates that two individuals are less genetically alike than two random ones (Hamilton 1970, Nature & Grafen 1985 Oxford Surveys in Evolutionary Biology). This has been invoked to explain the evolution of [[spite]]ful behaviour consisting of acts that result in harm, or loss of fitness, to both the actor and the recipient.
| |
| | |
| There has been little empirical support for Hamilton's rule in wild animals, as it is hard to quantify the costs and benefits of different behaviours. The first study to test Hamilton's rule successfully was in 2010, involving a wild population of [[Tamiasciurus hudsonicus|red squirrels]] in Yukon, Canada. The researchers found that surrogate mothers would adopt related orphaned squirrel pups but not unrelated orphans. The researchers calculated the cost of adoption by measuring a decrease in the survival probability of the entire litter after increasing the litter by one pup, while benefit was measured as the increased chance of survival of the orphan. The degree of relatedness of the orphan and surrogate mother for adoption to occur depended on the number of pups the surrogate mother already had in her nest, as this affected the cost of adoption. The study showed that females always adopted orphans when rB > C, but never adopted when rB < C, providing strong support for Hamilton's rule.<ref>{{cite journal |last=Gorrell J.C., McAdam A.G., Coltman D.W., Humphries M.M., Boutin S. |authorlink= |date=June 2010 |title=Adopting kin enhances inclusive fi tness in asocial red squirrels |journal=Nature Communications |volume=1 |issue=22 |pages= 1|doi=10.1038/ncomms1022 |url= |accessdate= |quote= |first1=Jamieson C. |first2=Andrew G. |first3=David W. |first4=Murray M. |first5=Stan }}</ref>
| |
| | |
| ==Mechanisms==
| |
| [[Altruism]] occurs where the instigating individual suffers a fitness loss while the receiving individual experiences a fitness gain. The sacrifice of one individual to help another is an example.
| |
| | |
| Hamilton (1964) outlined two ways in which kin selection altruism could be favoured:
| |
| | |
| {{quote|The selective advantage which makes behaviour conditional in the right sense on the discrimination of factors which correlate with the relationship of the individual concerned is therefore obvious. It may be, for instance, that in respect of a certain social action performed towards neighbours indiscriminately, an individual is only just breaking even in terms of inclusive fitness. If he could learn to recognise those of his neighbours who really were close relatives and could devote his beneficial actions to them alone an advantage to [[inclusive fitness]] would at once appear. Thus a mutation causing such discriminatory behaviour itself benefits inclusive fitness and would be selected. In fact, the individual may not need to perform any discrimination so sophisticated as we suggest here; a difference in the generosity of his behaviour according to whether the situations evoking it were encountered near to, or far from, his own home might occasion an advantage of a similar kind." (1996 [1964], 51)<ref name="Hamilton 1964 1–16"/>}}
| |
| | |
| '''Kin recognition''': First, if individuals have the [[kin recognition|capacity to recognize kin]] and to discriminate (positively) on the basis of [[kinship]], then the average relatedness of the recipients of altruism could be high enough for kin selection. Because of the facultative nature of this mechanism, kin recognition and discrimination are expected to be unimportant except among 'higher' forms of life such as the fish [[Neolamprologus pulcher]] (although there is some evidence for it among [[protozoa]]). Note also that kin recognition may be selected for inbreeding avoidance, and little evidence indicates that 'innate' kin recognition plays a role in mediating altruism. A thought experiment on the kin recognition/discrimination distinction is the hypothetical '[[Green-beard effect|green beard']], where a gene for social behaviour is imagined also to cause a distinctive phenotype that can be recognised by other carriers of the gene. Due to conflicting genetic similarity in the rest of the genome, there would be selection pressure for green-beard altruistic sacrifices to be suppressed, making common ancestry the most likely form of inclusive fitness.
| |
| | |
| '''Viscous populations''': Secondly, even indiscriminate altruism may be favoured in "viscous" populations with low rates or short ranges of dispersal. Here, social partners are typically genealogically close kin, and so altruism can flourish even in the absence of kin recognition and kin discrimination faculties — spatial proximity and circumstantial cues serving as a rudimentary form of discrimination. This suggests a rather general explanation for altruism. Directional selection always favours those with higher rates of fecundity within a certain population. Social individuals can often enhance the survival of their own kin by participating in and following the rules of their own group.
| |
| | |
| Hamilton later modified his thinking to suggest that an innate ability to recognise actual genetic relatedness was unlikely to be the dominant mediating mechanism for kin altruism:
| |
| | |
| {{quote|But once again, we do not expect anything describable as an innate kin recognition adaptation, used for social behaviour other than mating, for the reasons already given in the hypothetical case of the trees.(Hamilton 1987, 425)<ref name="H1987">Hamilton, W.D. (1987) ''Discriminating nepotism: expectable, common and overlooked''. In ''Kin recognition in animals'', edited by D. J. C. Fletcher and C. D. Michener. New York: Wiley.</ref>}}
| |
| | |
| Hamilton's later clarifications often go unnoticed, and because of the long standing assumption that kin selection requires innate powers of kin recognition, some theorists have tried to clarify the position in recent work:
| |
| | |
| {{quote|In his original papers on inclusive fitness theory, Hamilton pointed out a sufficiently high relatedness to favour altruistic behaviours could accrue in two ways — kin discrimination or limited dispersal ( Hamilton, 1964, 1971,1972, 1975). There is a huge theoretical literature on the possible role of limited dispersal reviewed by Platt & Bever (2009) and West et al. (2002a), as well as experimental evolution tests of these models (Diggle et al., 2007; Griffin et al., 2004; Kümmerli et al., 2009 ). However, despite this, it is still sometimes claimed that kin selection requires kin discrimination (Oates & Wilson, 2001; Silk, 2002 ). Furthermore, a large number of authors appear to have implicitly or explicitly assumed that kin discrimination is the only mechanism by which altruistic behaviours can be directed towards relatives... [T]here is a huge industry of papers reinventing limited dispersal as an explanation for cooperation. The mistakes in these areas seem to stem from the incorrect assumption that kin selection or indirect fitness benefits require kin discrimination (misconception 5), despite the fact that Hamilton pointed out the potential role of limited dispersal in his earliest papers on inclusive fitness theory (Hamilton, 1964; Hamilton, 1971; Hamilton, 1972; Hamilton, 1975). (West et al. 2010, p.243 and supplement)<ref name="W2010">West et al. 2011. Sixteen common misconceptions about the evolution of cooperation in humans. Evolution and Social Behaviour 32 (2011) 231-262</ref>}}
| |
| | |
| The assumption that kin recognition must be innate, and that cue-based mediation of social cooperation based on limited dispersal and shared developmental context are not sufficient, has obscured significant progress made in applying kin selection and inclusive fitness theory to a wide variety of species, including humans,<ref name="SBNK">[http://papers.ssrn.com/sol3/papers.cfm?abstract_id=1791365 Holland, Maximilian. (2004) ''Social Bonding and Nurture Kinship: Compatibility between Cultural and Biological Approaches''. London School of Economics, PhD Thesis]</ref> on the basis of cue-based mediation of social bonding and social behaviours.
| |
| | |
| ==Kin selection and human social patterns==
| |
| [[File:Coloured-family.jpg|thumb|[[Family|Families]] are important in human behaviour, but kin selection may be based on closeness and other cues.]]
| |
| {{See also|Darwinian anthropology|Nurture kinship}}
| |
| | |
| [[Evolutionary psychology|Evolutionary psychologists]], following [[Darwinian anthropology|Darwinian anthropologists']] interpretation<ref name="D&W1999">Daly, M. and Wilson, M.I. (1999) ''An evolutionary psychological perspective on homicide''. In ''Homicide Studies: A Sourcebook of Social Research'', edited by D. Smith and M. Zahn. Thousand Oaks: Sage Publications</ref> of kin selection theory initially attempted to explain human altruistic behaviour through kin selection by stating that "behaviors that help a genetic relative are favored by natural selection." However, most Evolutionary psychologists recognize that this common shorthand formulation is inaccurate;
| |
| | |
| {{quote|[M]any misunderstandings persist. In many cases, they result from conflating "coefficient of relatedness" and "proportion of shared genes," which is a short step from the intuitively appealing—but incorrect—interpretation that "animals tend to be altruistic toward those with whom they share a lot of genes." These misunderstandings don’t just crop up occasionally; they are repeated in many writings, including undergraduate psychology textbooks—most of them in the field of social psychology, within sections describing evolutionary approaches to altruism. (Park 2007, p860)<ref name="P2007">Park, J.H. (2007) ''Persistent Misunderstandings of Inclusive Fitness and Kin Selection: Their Ubiquitous Appearance in Social Psychology Textbooks''. Evolutionary Psychology 5(4): 860-873.</ref>}}
| |
| | |
| As with the earlier sociobiological forays into the cross-cultural data, typical approaches are not able to find explanatory fit with the findings of ethnographers insofar that human kinship patterns are not necessarily built upon blood-ties. However, as Hamilton's later refinements of his theory make clear, it does not simply predict that genetically related individuals will inevitably recognise and engage in positive social behaviours with genetic relatives: rather, indirect context-based mechanisms may have evolved, which in historical environments have met the inclusive fitness criterion (see above section). Consideration of the demographics of the typical evolutionary environment of any species is crucial to understanding the evolution of social behaviours. As Hamilton himself puts it, "Altruistic or selfish acts are only possible when a suitable social object is available. In this sense behaviours are conditional from the start." (Hamilton 1987, 420).<ref name="H1987" />
| |
| | |
| Under this perspective, and noting the necessity of a reliable context of interaction being available, the data on how altruism is mediated in social mammals is readily made sense of. In social mammals, primates and humans, altruistic acts that meet the kin selection criterion are typically mediated by circumstantial cues such as shared developmental environment, familiarity and social bonding.<ref name="S1997">Sherman et al (1997) ''Recognition Systems''. In ''Behavioural Ecology'', edited by J. R. Krebs and N. B. Davies. Oxford: Blackwell Scientific.</ref> That is, it is the context that mediates the development of the bonding process and the expression of the altruistic behaviours, not genetic relatedness ''per se''. This interpretation thus is compatible with the cross-cultural ethnographic data<ref name="SBNK"/> and has been called [[nurture kinship]].
| |
| | |
| ==Examples==
| |
| [[File:Kin selection.JPG|thumb|320|Experiment about kin selection]]
| |
| | |
| [[Eusociality]] (true sociality) is used to describe social systems with three characteristics: one is an overlap in generations between parents and their offspring, two is cooperative brood care, and the third characteristic is specialized castes of nonreproductive individuals.<ref name="Freeman2007">{{cite book |title=Evolutionary Analysis |last=Freeman |first=Scott |authorlink= |coauthors=Herron, Jon C. |year=2007 |edition=4th |publisher=Pearson, Prentice Hall |location=Upper Saddle River, NJ |isbn=0-13-227584-8 |page=460 |pages= |url= }}</ref> The social insects provide good examples of organisms with what appear to be kin selected traits. The workers of some species are sterile, a trait that would not occur if individual selection was the only process at work. The relatedness coefficient ''r'' is abnormally high between the worker sisters in a colony of [[Hymenoptera]] due to [[Haplodiploid sex-determination system|haplodiploidy]]. Hamilton's rule is presumed to be satisfied because the benefits in [[fitness (biology)|fitness]] for the workers are believed to exceed the costs in terms of lost reproductive opportunity, though this has never been demonstrated empirically. There are competing hypotheses, as well, which may also explain the evolution of social behavior in such organisms.<ref name=NTW/>
| |
| | |
| Another example is preference among individuals in [[sun-tailed monkey]] communities. A study showed that maternal kin (kin related to by mothers) favoured each other, but that with relatives more distant than half-siblings, this bias dropped significantly.<ref name=Charpentier2008>{{cite journal | url = http://www.cefe.cnrs.fr/coev/pdf/charpentier/Charpentier%20et%20al%2008%20Int%20J%20Primatol.pdf | doi = 10.1007/s10764-008-9246-9 | author = Charpentier, Marie | journal = International Journal of Primatology | volume = 29 | issue = 2 | pages = 487–495 | year = 2008 | title = Relatedness and Social Behaviors in Cercopithecus solatus | accessdate = 2011-07-28 | publisher = Springer Link | first2 = Delphine | first3 = Patricia}}</ref>
| |
| | |
| Alarm calls in ground squirrels are another example. While they may alert others of the same species to danger, they draw attention to the caller and expose it to increased risk of predation. Paul Sherman studied the alarm calls of ground squirrels, observing that the calls occurred most frequently when the caller had relatives nearby.<ref name=Milius1998>{{cite journal
| |
| | url = http://findarticles.com/p/articles/mi_m1200/is_n11_v154/ai_21156998 | doi = 10.2307/4010761 | author = Milius, Susan | journal = Science News | volume = 154 | issue = 11 | pages = 174–175 | year = 1998 | title = The Science of Eeeeek! | accessdate = 2008-07-02 | jstor = 4010761 | publisher = Science News, Vol. 154, No. 11}}</ref> In a similar study, John Hoogland followed individual males through different stages of life. Male prairie dogs modified their rate of calling when closer to kin. These behaviours show that self-sacrifice is directed towards close relatives, and that there is an indirect fitness gain.<ref name="Freeman2007" />
| |
| | |
| Alan Krakauer of [[University of California, Berkeley]] has studied kin selection in the courtship behavior of wild turkeys. Like a teenager helping her older sister prepare for a party, a subordinate turkey may help his dominant brother put on an impressive team display that is only of direct benefit to the dominant member.<ref>[http://www.berkeley.edu/news/media/releases/2005/03/02_turkeys.shtml In the mating game, male wild turkeys benefit even when they do not get the girl], Robert Sanders</ref>
| |
| | |
| Recent studies provide evidence that even certain plants can recognize and respond to kinship ties. Using [[sea rocket]] for her experiments, Susan Dudley at [[McMaster University]] in [[Canada]] compared the growth patterns of unrelated plants sharing a pot to plants from the same clone. She found that unrelated plants competed for soil nutrients by aggressive root growth. This did not occur with sibling plants.<ref name=Smith2007>{{cite journal | url = http://www.k8science.org/news/news.cfm?art=3379 | doi = 10.1038/news070611-4 | title = Plants can tell who's who | year = 2007 | author = Smith, Kerri | journal = Nature News}}</ref>
| |
| | |
| In the [[wood mouse]] (''{{lang|la|Apodemus sylvaticus}}''), aggregates of spermatozoa form mobile trains, some of the spermatozoa undergo premature acrosome reactions that correlate to improved mobility of the mobile trains towards the female egg for fertilization. This association is thought to proceed as a result of a "green beard effect" in which the spermatozoa perform a kin-selective altruistic act after identifying genetic similarity with the surrounding spermatozoa.<ref>{{cite journal |last=Moore |first=Harry |authorlink= |year=2002 |month= |title=Exceptional sperm cooperation in the wood mouse |journal=Nature |volume=418 |issue=6894 |pages=174–177 |doi=10.1038/nature00832 |url= |accessdate= |quote= |pmid=12110888 |display-authors=1 |last2=Dvoráková |first2=Katerina |last3=Jenkins |first3=Nicholas |last4=Breed |first4=William }}</ref>
| |
| | |
| ==Human examples==
| |
| Whether or not [[Hamilton's rule]] always applies, studies have demonstrated that relatedness is often important for human altruism in that humans are inclined to behave more altruistically toward kin than toward unrelated individuals.<ref name=Cartwright>Cartwright, J. (2000). ''Evolution and human behavior: Darwinian perspectives on human nature.'' Massachusetts: MIT Press.</ref> Many people choose to live near relatives, exchange sizable gifts with relatives, and favour relatives in wills in proportion to their relatedness.<ref name=Cartwright/>
| |
| | |
| ===Experimental studies, interviews, and surveys===
| |
| A study interviewed several hundred women in Los Angeles to study patterns of helping between kin versus non-kin. While non-kin friends were willing to help one another, their assistance was far more likely to be reciprocal. The largest amounts of non-reciprocal help, however, were reportedly provided by kin. Additionally, more closely related kin were considered more likely sources of assistance than distant kin.<ref>{{cite journal | author = Essock-Vitale S.M., McQuire M.T. | year = 1985 | title = Women's lives viewed from an evolutionary perspective. II. Patterns in helping | url = | journal = Ethology and Sociobiology | volume = 6 | issue = 3| pages = 155–173 | doi = 10.1016/0162-3095(85)90028-7 }}</ref> Similarly, several surveys of American college students found that individuals were more likely to incur the cost of assisting kin when a high probability that relatedness and benefit would be greater than cost existed. Participants’ feelings of helpfulness were stronger toward family members than non-kin. Additionally, participants were found to be most willing to help those individuals most closely related to them. Interpersonal relationships between kin in general were more supportive and less Machiavellian than those between non-kin.<ref>{{cite journal | author = Barber N | year = 1994 | title = Machiavellianism and altruism: Effects of relatedness of target person on Machiavellian and helping attitudes | url = | journal = Psychological Report | volume = 75 | issue = | pages = 403–22 | doi = 10.2466/pr0.1994.75.1.403 }}</ref>
| |
| | |
| In one experiment, the longer participants (from both the UK and the South African Zulus) held a painful skiing position, the more money or food was presented to a given relative. Participants repeated the experiment for individuals of different relatedness (parents and siblings at r = .5, grandparents, nieces, and nephews at r = .25, etc.). The results showed that participants held the position for longer intervals the greater the degree of relatedness between themselves and those receiving the reward.<ref>{{cite journal | author = Madsen E.A. | year = 2007 | title = Kinship and altruism: A cross-cultural experimental study | url = | journal = British Journal of Psychology | volume = 98 | issue = Pt 2| pages = 339–359 | doi = 10.1348/000712606X129213 | pmid = 17456276 | author-separator = , | author2 = Tunney R.J. | author3 = Fieldman G. | display-authors = 3 | last4 = Plotkin | first4 = Henry C. | last5 = Dunbar | first5 = Robin I. M. | last6 = Richardson | first6 = Jean-Marie | last7 = McFarland | first7 = David }}</ref>
| |
| | |
| ===Observational studies===
| |
| A study of food-sharing practices on the West Caroline islets of Ifaluk determined that food-sharing was more common among people from the same islet, possibly because the degree of relatedness between inhabitants of the same islet would be higher than relatedness between inhabitants of different islets. When food was shared between islets, the distance the sharer was required to travel correlated with the relatedness of the recipient—a greater distance meant that the recipient needed to be a closer relative. The relatedness of the individual and the potential inclusive fitness benefit needed to outweigh the energy cost of transporting the food over distance.<ref>{{cite journal | author = Betzig L., Turke P. | year = 1986 | title = Food sharing on Ifaluk | url = | journal = Current Anthropology | volume = 27 | issue = 4| pages = 397–400 | doi = 10.1086/203457 }}</ref>
| |
| | |
| Humans may use the inheritance of material goods and wealth to maximize their inclusive fitness. By providing close kin with inherited wealth, an individual may improve his or her kin’s reproductive opportunities and thus increase his or her own inclusive fitness even after death. A study of a thousand wills found that the beneficiaries who received the most inheritance were generally those most closely related to the will’s writer. Distant kin received proportionally less inheritance, with the least amount of inheritance going to non-kin.<ref>{{cite journal | author = Smith M., Kish B., Crawford C. | year = 1987 | title = Inheritance of wealth as human kin investment | url = | journal = Ethology and Sociobiology | volume = 8 | issue = 3| pages = 171–182 | doi = 10.1016/0162-3095(87)90042-2 }}</ref>
| |
| | |
| A study of childcare practices among Canadian women found that respondents with children provide childcare reciprocally with non-kin. The cost of caring for non-kin was balanced by the benefit a woman received—having her own offspring cared for in return. However, respondents without children were significantly more likely to offer childcare to kin. For individuals without their own offspring, the inclusive fitness benefits of providing care to closely related children might outweigh the time and energy costs of childcare.<ref>{{cite journal | author = Davis J.N., Daly M. | year = 1997 | title = Evolutionary theory and the human family | url = | journal = Quarterly Review of Biology | volume = 72 | issue = 4| pages = 407–35 | doi = 10.1086/419953 | pmid = 9407672 }}</ref>
| |
| | |
| Family investment in offspring among black South African households also appears consistent with an inclusive fitness model.<ref>{{cite journal | author = Anderson K.G. | year = 2005 | title = Relatedness and investment: Children in South Africa | url = | journal = Human Nature—An Interdisciplinary Biosocial Perspective | volume = 16 | issue = | pages = 1–31 }}</ref> A higher degree of relatedness between children and their caregivers frequently correlated with a higher degree of investment in the children, with more food, health care, and clothing being provided. Relatedness between the child and the rest of the household also positively associated with the regularity of a child’s visits to local medical practitioners and with the highest grade the child had completed in school. Additionally, relatedness negatively associated with a child’s being behind in school for his or her age.
| |
| | |
| Observation of the Dolgan hunter-gatherers of northern Russia suggested that, while reciprocal food-sharing occurs between both kin and non-kin, there are larger and more frequent asymmetrical transfers of food to kin. Kin are also more likely to be welcomed to non-reciprocal meals, while non-kin are discouraged from attending. Finally, even when reciprocal food-sharing occurs between families, these families are often very closely related, and the primary beneficiaries are the offspring.<ref>{{cite journal | author = Ziker J., Schnegg M. | year = 2005 | title = Food sharing at meals: Kinship, reciprocity, and clustering in the Taimyr Autonomous Okrug, northern Russia | url = | journal = Human Nature—An Interdisciplinary Biosocial Perspective | volume = 16 | issue = | pages = 178–210 }}</ref>
| |
| | |
| Other research indicates that violence in families is more likely to occur when step-parents are present and that "genetic relationship is associated with a softening of conflict, and people's evident valuations of themselves and of others are systematically related to the parties' reproductive values".<ref>{{cite journal | author = Daly M., Wilson M. | year = 1988 | title = Evolutionary social-psychology and family homicide | url = | journal = Science | volume = 242 | issue = 4878| pages = 519–524 | doi = 10.1126/science.3175672 | pmid = 3175672 }}</ref>
| |
| | |
| Numerous other studies suggest how inclusive fitness may work amongst different peoples, such as the Ye’kwana of southern Venezuela, the Gypsies of Hungary, and the doomed Donner Party of the United States.<ref>{{cite journal | author = Hames R | year = 1979 | title = Garden labor exchange among the Ye'kwana | url = | journal = Ethology and Sociobiology | volume = 8 | issue = 4| pages = 259–84 | doi = 10.1016/0162-3095(87)90028-8 }}</ref><ref>{{cite journal | author = Bereczkei T | year = 1998 | title = Kinship network, direct childcare, and fertility among Hungarians and Gypsies | url = | journal = Evolution and Human Behavior | volume = 19 | issue = 5| pages = 283–298 | doi = 10.1016/S1090-5138(98)00027-0 }}</ref><ref>{{cite journal | author = Grayson D. K. | year = 1993 | title = Differential mortality and the Donner Party disaster | url = | journal = Evolutionary Anthropology | volume = 2 | issue = 5| pages = 151–9 | doi = 10.1002/evan.1360020502 }}</ref><ref>Hughes, A.L. (1988). ''Evolution and human kinship.'' Oxford: Oxford University Press.</ref><ref>Dunbar, R. (2008). Kinship in biological perspective. In N.J. Allen, H. Callan, R. Dunbar, W. James (Eds.), ''Early human kinship: From sex to social reproduction'' (131-150). New Jersey: Blackwell Publishing Ltd.</ref>
| |
| | |
| ==Non-human examples==
| |
| [[Vervet monkey]]s display kin selection between siblings, mothers and offspring, and grandparent-grandchild. These monkeys utilize [[allomothering]], where the allomother is typically an older female sibling or a grandmother. Other studies have shown that individuals will act aggressively toward other individuals that were aggressive toward their relatives.<ref name="sibships">Lee, P.C. “Sibships: Cooperation and Competition Among Immature Vervet Monkeys.” [[Primates]]. Vol 28(1): 47-59. 1987</ref><ref name="allomother">CFairbanks, Lynn A. “Reciprocal benefits of allomothering for female vervet monkeys.” [[Animal Behaviour]]. Vol 40: 553-562. 1990</ref>
| |
| | |
| ''[[Synalpheus regalis]]'' is a eusocial shrimp that protects juveniles in the colony. By defending the young, the large defender shrimp can increase its inclusive fitness. [[Allozyme]] data revealed that relatedness within colonies is high, averaging 0.50, indicating that colonies in this species represent close kin groups.<ref name=Colony>{{cite journal |author=J. Emmett Duffy, Cheryl L. Morrison & Kenneth S. Macdonald |title=Colony defense and behavioral differentiation in the eusocial shrimp ''Synalpheus regalis'' |journal=[[Behavioral Ecology and Sociobiology]] |year=2002 |volume=51 |issue=5 |pages=488–495 |url=http://www.vims.edu/research/units/labgroups/marine_biodiversity/publications/_pdf/Duffy_et_al_2002_BES.PDF |format=[[Portable Document Format|PDF]] |doi=10.1007/s00265-002-0455-5}}</ref>
| |
| | |
| ==Criticism==
| |
| | |
| The theory of kin selection was criticized in two studies, one published in 1998<ref>{{cite journal | author = Alonso, W| year = 1998| title = The role of Kin Selection theory on the explanation of biological altruism: A critical Review| url = http://www.origem.info/KS/Alonso_1998.pdf | journal = Journal of Comparative Biology| volume = 3| issue = 1| pages = 1–14}}</ref> and another in 2002 in PNAS.<ref>{{cite journal | author = Alonso, WJ; Schuck-Paim C| year = 2002| title = Sex-ratio conflicts, kin selection, and the evolution of altruism| url = http://www.pnas.org/content/99/10/6843.full| journal = PNAS| volume = 99 | issue = 10| pages = 6843–6847| doi = 10.1073/pnas.092584299 | pmid = 11997461 | pmc = 124491 }}</ref> Alonso and Schuck-Paim argue that the behaviours which kin selection attempts to explain are not altruistic (in pure Darwinian terms) because: (1) they may directly favour the performer as an individual aiming to maximize its progeny (so the behaviours can be explained as ordinary individual selection); (2) these behaviours benefit the group (so they can be explained as group selection); or (3) they are by-products of a developmental system of many "individuals" performing different tasks (like a colony of bees, or the cells of multicellular organisms, which are the focus of selection). They also argue that the genes involved in sex ratio conflicts could be treated as "parasites" of (already established) social colonies, not as their "promoters", and, therefore the sex ratio in colonies would be irrelevant to the transition to eusociality. Those papers were mostly ignored until they were re-edited by [[Martin Nowak]], Corina Tarnita, and [[E. O. Wilson]]. These latter authors argue that
| |
| | |
| {{quote|Inclusive fitness theory is not a simplification over the standard approach. It is an alternative accounting method, but one that works only in a very limited domain. Whenever inclusive fitness does work, the results are identical to those of the standard approach. Inclusive fitness theory is an unnecessary detour, which does not provide additional insight or information.|Nowak, Tarnita, and Wilson<ref name=NTW/>}}
| |
| | |
| They, like Alonso (1998) and Alonso and Schuck-Paim (2002) earlier, argue for a [[Group selection|multi-level selection]] model instead.<ref name=NTW/> This aroused a strong response, including a rebuttal published in Nature from over a hundred researchers.<ref>Abbot ''et al'' (2011) Inclusive fitness theory and eusociality. ''Nature'' '''471''': E1-E4 ({{doi|10.1038/nature09831}})</ref>
| |
| | |
| ==See also==
| |
| * [[Ethnic nepotism]]
| |
| * [[Darwinian anthropology]]
| |
| * [[Price equation]]
| |
| * ''[[The Selfish Gene]]''
| |
| * [[The kinship theory of genomic imprinting]]
| |
| | |
| ==References==
| |
| {{reflist|30em}}
| |
| | |
| ==Further reading==
| |
| {{refbegin}}
| |
| * {{cite journal
| |
| | doi = 10.1016/0022-5193(64)90038-4
| |
| | author = Hamilton, W.D.
| |
| | journal = Journal of Theoretical Biology
| |
| | volume = 7
| |
| | issue = 1
| |
| | pages = 1–16
| |
| | year = 1964
| |
| | title = The Genetical Evolution of Social Behaviour. I
| |
| | pmid = 5875341}}
| |
| * {{cite journal
| |
| | doi = 10.1016/0022-5193(64)90039-6
| |
| | author = Hamilton, W.D.
| |
| | journal = Journal of Theoretical Biology
| |
| | volume = 7
| |
| | issue = 1
| |
| | pages = 17–52
| |
| | year = 1964
| |
| | title = The Genetical Evolution of Social Behaviour. II
| |
| | pmid = 5875340}}
| |
| * {{cite journal
| |
| | doi = 10.1006/anbe.1996.0019
| |
| | author = Lucas, J.R.; Creel, S.R.; Waser, P.M.
| |
| | journal = Animal Behaviour
| |
| | volume = 51
| |
| | issue = 1
| |
| | pages = 225–228
| |
| | year = 1996
| |
| | title = How to Measure Inclusive Fitness, Revisited}}
| |
| * {{cite journal
| |
| | doi = 10.1348/000712606X129213
| |
| | author = Madsen, E.A.; Tunney, R.J.; Fieldman, G.; Plotkin, H.C.; Dunbar, R.I.M.; Richardson, J.M.; McFarland, D.
| |
| | journal = British Journal of Psychology
| |
| | volume = 98
| |
| | issue = 2
| |
| | pages = 339–359
| |
| | year = 2007
| |
| | title = Kinship and Altruism: a Cross-Cultural Experimental Study
| |
| | pmid = 17456276}}
| |
| * Queller, D.C. & Strassman, J.E. (2002) [http://www.ruf.rice.edu/%7Eevolve/pdf/20002001/CurBio2002_12_R832.pdf Quick Guide: Kin Selection]. ''[[Current Biology]]'','''12''',R832.
| |
| * West, S.A., Gardner, A. & Griffin, A.S. (2006) [http://westgroup.biology.ed.ac.uk/pdf/West_etal_06_altruism.pdf Quick Guide: Altruism]. ''Current Biology'','''16''',R482-R483.
| |
| {{refend}}
| |
| | |
| <!-- AWB Bots, don't touch this pre-infobox space! --> | |
| | |
| {{sociobiology}}
| |
| {{evolutionary psychology}}
| |
| | |
| {{DEFAULTSORT:Kin Selection}}
| |
| [[Category:Selection]]
| |
| [[Category:Theories of history]]
| |
| [[Category:Evolutionary biology]]
| |
| | |
| {{Link GA|fi}}
| |
each division has its own heavy fire spirit
On that side of the bones, 一枚 white 'color' is satisfied that every now and then the sky, fall into their hands, flexor of a bomb, a roll of pale 'color' of the 腕時計 メンズ casio reel is present in its front, above the reel, drawing some Quintana beast birds braved flames.
'This is the year of the famous old カシオ gps 時計 lady fighting skills,' five from the Fire, 'Oh, that's fighting skills are also some wrong, it should be said that the law must casio 腕時計 データバンク control the fire.' Venerable Skyfire will then reel カシオ 掛け時計 thrown Xiao Yan, said: 'As long as you can help the old lady, then this thing will be yours, if you doubt the sincerity of the old lady, you can take the reel, was found to be no problem, then help me to repair the soul too late.'
cautiously took the reel, Xiao Yan hesitated a moment, just cautious gradually spread.
'five from Fire, fire control method formula, France is divided into five weight, according to the zoomorphic and identified, wolves, leopards, lions, tigers, Jiao, each division has its own heavy 時計 カシオ fire spirit, France tactic Dacheng, five animals gathered ,
相关的主题文章：
his eyes also promised some more excitement' color. '
Thing! 'Words to the end, on the face of the emergence of a large Presbyterian touch ruddy, his eyes also カシオ 腕時計 ソーラー promised some more excitement' color. '
hear this big elders has not been determined, Xiao Yan and Medusa are a heavy sigh of relief, perhaps this is カシオ腕時計 メンズ just an accident
'Whether this is true, you have to remember, perhaps later to be extra careful to wait a period of time, that is, your body is able to determine what the reason.' Qiaode It looks like Medusa, a large Presbyterian brow wrinkled, Chen Sheng said.
'this time is how long?' Xiao Yan stem asked with a smile.
'snake Terran Unlike humans, especially blood or Medusa, if indeed pregnant, time will not short, three to five years is the normal things.' great elders faint.
Wen Yan, Xiao Yan mind カシオ ソーラー 腕時計 again relieved, okay, if this two-month カシオ 腕時計 バンド period to カシオ 腕時計 ソーラー 電波 determine the case, then he really jumped from the wall
相关的主题文章：
vague hoarse voice
Under its frustration when it will exit so state, that is about to dissipate depleted grain dust pregnant spirit within my mind, but it is suddenly a burst of intense light, etc. In this カシオ電波ソーラー腕時計 light, even even Xiao Yan soul are all feeling a sharp pain in the emergence.
pain gradually fade, カシオソーラー時計 in some panic among Xiao Yan, at the outbreak of that light, casio 腕時計 スタンダード it was a faint sound came between extremely low blurred the old 'Yin'
'very soul カシオの時計 of ... close ... Carolina Ling Ling Shou days forging Soul'
vague hoarse voice, whispering in XiaoYan minds back to 'swing', like Fine resounded like to make people kind of get a casio 腕時計 phys sense of trance.
Trance does not make sense
Xiao Yan therefore absence, and that the sound of the minds of old, although vague, but it is possible he jotted down a lot, and this old sound, in retrospect it three times After that is thoroughly dissipated away
room
相关的主题文章：
wooden box open
Smile, the two boxes, open simultaneously.
wooden box open, 'Lucy,' one カシオ電波ソーラー腕時計 of the two items, one is a fist-sized red 'color' round beads, the second is a gray brown 'color' of unusual bamboo.
Hsiao go far people's eyes, first brought together the egg on top of red beads, they can feel it being quite violent and contains an enormous fire is 'sexual' energy.
'This is a magic nucleus?' Xiao Yan eyes firmly fixed on the red beads While カシオ レディース 電波ソーラー腕時計 some less certain way, so a high level of magic nucleus, but the first time I saw him.
'ah, is indeed a magic nuclear grade, but not low, but still kind of afraid of the higher-order form of Warcraft, or difficult to have such a' color カシオ 腕時計 ソーラー 電波 'and energy.'
Soviet casio 腕時計 説明書 Union thousands stroking his beard, his eyes passing touch alarmed, said: 'This is magic nucleus, as I guess 電波時計 カシオ it should be a seven-order fire is' sexual 'magic nucleus, no
相关的主题文章：