Some researchers suggest that, taken as a whole, active powers of recognition play a negligible role in mediating social cooperation relative to less elaborate cue-based and context-based mechanisms, such as familiarity and imprinting, whereas other researchers argue that specialized kin recognition mechanisms, such as phenotype matching, are widespread in facilitating nepotism.
A well-known human example of an inbreeding avoidance mechanism is the Westermarck effect, in which unrelated individuals who happen to spend their childhood in the same household find each other sexually unattractive.
Hamilton's early papers, as well as giving a mathematical account of the selection pressure, discussed possible implications and behavioural manifestations.
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.
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."
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 ).
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.
(Grafen 1991, 1095)[8]Others have cast similar doubts over the enterprise: [T]he fact that animals benefit from engaging in spatially mediated behaviors is not evidence that these animals can recognize their kin, nor does it support the conclusion that spatially based differential behaviors represent a kin recognition mechanism (see also discussions by Blaustein, 1983; Waldman, 1987; Halpin 1991).
[11] Mateo notes that the squirrels spent longer investigating non-kin scents suggesting recognition of kin odor.
It's also noted that Belding's ground squirrels produce at least two scents arising from dorsal and oral secretions, giving two opportunities for kin recognition.
Black Rock Skink recognize their family groups based on prior association and not how genetically related the other lizards are to themselves.
[14] Studies suggest that the bald-faced hornet, Dolichovespula maculata, can recognize nest mates by their cuticular hydrocarbon profile, which produces a distinct smell.
Laboratory tests[16] indicate that females can discriminate between kin and nonkin, close and distant relatives and, within-litters, between full-siblings and maternal half-siblings.
[24] Kin recognition is an adaptive behavior observed in living beings to prevent inbreeding, and increase fitness of populations, individuals and genes.
This study was performed using secretion inhibitors, which disabled the mechanism responsible for kin recognition in this species, and showed similar growth patterns to Bhatt et al., (2010) and Murphy and Dudley (2009) in control groups.
Researchers also concluded that the auxin-synthesis gene TAA1 is involved in the process, downstream of the photoreceptors, by performing a similar experiments using Sav3 knock-out mutants.
This mechanism leads to altered leaf direction to prevent shading of related neighbors and to reduce competition for sunlight.
In the house mouse, the major urinary protein (MUP) gene cluster provides a highly polymorphic scent signal of genetic identity that appears to underlie kin recognition and inbreeding avoidance.
[36] Thus, kin recognition at the level of the pollen tube apparently leads to post-pollination selection to avoid inbreeding depression.