Genes Preserved in Relatives
S.W. Guo, M. Xiong
Human Heredity,
47(3), 138-154 (May-June 1997)
Abstract
The genes of an individual are said to be preserved in his relatives if
they possess, collectively, all copies of his genes. We present a method
for computing the probability that an individual's genes are preserved
in his relatives. Using this method, we compute gene preservation
probabilities (up to three linked loci) for a variety of relationships for
humans and for haplodiploid species. The results suggest that some
widely held notions in ethology and sociobiology seem to be
questionable. From the gene preservation viewpoint, two brothers are
far from enough to justify the sacrifice of one's own life, because the
probability that an individual's genes are preserved in his two siblings
is dismally small. The precise probability that an individual's genes
are all preserved in a group of his relatives depends on the precise
specification of the pedigree structure. We also demonstrate that, for a
hymenopteran female, there is no practical difference, in terms of
gene preservation probability, between helping her sisters to breed and
breeding her own offspring. In fact, since the genes of her sister will
be either lost or preserved in her nieces/nephews, it is more
appropriate to compare the probability of preserving her genes
through her own offspring with that through her nieces/nephews. We
show that her chance of preserving all her genes is much higher if she
chooses to breed her own offspring instead of helping her sister.