A novel approach based on graph theory is presented to reason about the genetic contribution of
ancestors at
different genealogical distances from today's individuals (different definitions of
layers and distances are propos
ed and discussed). It allows the maximum likelihood
classification of specific founders who predominantly
contribute to one class of individuals and the analysis of separability of specific founders with respect to two
classes of individuals that have been selected based on LOD (logarithm of odds) score
determined by a total genome scan and on ScaI
marker genotype of a candidate gene of
hypertension, ANP. Several experiments have
been performed on a genealogy comprising more
than 40,000 people and spanning 17
generations from the Saguenay-Lac-Saint-Jean
population.
We have computed: the founders obtained by using
different definitions of layers and distances,
the contribution of specific and unique founders, and the separability of specific founders. The
results indicate that most defini
tions of layers of founders show a similar trend over layers for
size and content, that specific and unique genetic contributions are very high for recent
generations and, as expected, decrease for older generations, and, also, that separability is higher
for recent generations than for older ones. The
presented approach allows a much finer grain
analysis of genetic contribution of founders than previously-reported approaches