Biology
Roz
Model4.pptKinship
*
Overview
- Inclusive fitness theory
- Recognizing kinship
- Parent-offspring conflict
- Sibling conflict
Inclusive fitness theory
(Hamilton 1964)
- Fitness = total number of an individual’s descendants
- But also share genes with relatives so their offspring are essentially party yours as well (shared genes)
- Conceptualized individual’s total fitness as the number of its own offspring as well as the offspring of its genetic relatives (albeit reduced by relatedness)
- In terms of genetic fitness, my sister having two children is the same as me having one child
Just as helping your own offspring increase your chance of genetic representation in later generations, so does helping others that share your genes as well, albeit to a lesser extent, thus the costs must be low.
Kin recognition: if kinship is important, you should probably know how to detect them
Two models of recognition
- Matching
- Rule of thumb
The global extent of the large supercolony (red, orange) and populations containing other, behaviorally distinct supercolonies (gray). Sites tested in this study and shown to belong to the same transcontinental supercolony are shown as red squares. Sites shown as orange circles also belong to this supercolony, based on data from this and other studies (Tsutsui et al. 2000; Giraud et al. 2002; Wetterer and Wetterer 2006; Corin et al. 2007a; Bjorkman-Chiswell et al. 2008; Suhr et al. 2009). Gray squares mark the locations that do not belong to this colony. Colonies in the native range, which typically show aggression at much smaller spatial scales, are shown as gray circles.
Bank Swallow, Riparia riparia
Rule of thumb:
If there is an individual in your nest, they are probably your kin
…unless of course they are slave-making ants, Polyergus spp.
Ancestrally, if an individual observed an infant in a perinatal association with the individual’s mother, then it was highly probable that that infant was the individual’s sibling.
“Previous studies in animals and humans show that genes in the major histocompatibility complex (MHC) influence individual odours and that females often prefer odour of MHC-dissimilar males, perhaps to increase offspring heterozygosity or reduce inbreeding. Women using oral hormonal contraceptives, [or are pregnant] have been reported to have the opposite preference…”
Parent-Offspring conflict
FGR was greater in polyandrous than monogomous species
Sibling Conflict
In the Ottoman Empire a policy of judicial royal fratricide was introduced by Sultan Mehmet II whose grandfather Mehmed I had to fight a long and bloody civil war against his brothers (which brought the empire near to destruction) to take the throne. When a new Sultan ascended to the throne he would imprison all of his surviving brothers and kill them by strangulation with a silk cord as soon as he had produced his first male heir. The largest killing took place on the succession of Mehmed III when 19 of his brothers were killed and buried with their father. The aim was to prevent civil war. Reflecting public disapproval, his successor Ahmed I abandoned the practice, replacing it with life imprisonment in the Kafes, a section of the Ottoman palace.
Food Amount Hypothesis
