the percentage of the inheritance of obesity that is accounted for by genetic factors is about
Genetics of obesity Polymorphisms in various genes controlling appetite and metabolism predispose to obesity under certain dietary conditions. The percentage of obesity that can be attributed to genetics varies widely, depending on the population examined, from 6% to 85%.[6] As of 2006, more than 41 sites on the human genome have been linked to the development of obesity when a favorable environment is present.[7] The involvement of genetic factors in the development of obesity is estimated to be 40â€“70%. Some of these obesogenic or leptogenic genes may influence obese individuals response to weight loss or weight management.[8]
Kin selection 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. Under natural selection, a gene encoding a 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 behaviour, 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".[15] This analysis has been challenged,[16] Wilson writing that "the foundations of the general theory of inclusive fitness based on the theory of kin selection have crumbled"[17] and that he now relies instead on the theory of eusociality and "gene-culture co-evolution" for the underlying mechanics of sociobiology.