The answer is an overhunting.
<span>The bottleneck event means drastic reduction of the population size because of environment changes. The consequence of this is the reduction of genetic variation. The bison population is a good example of the population bottleneck. The bison population drastically reduced its size due to overhunting which culminated at the end of the 19th century, when bisons almost extinct. </span>
It is 0%. They only have the recessive alleles (ss) so there is no possibility it can ever produce a gamete with a dominant allele (S). For example, if it was Ss it would be 50%, and for SS it would be 100%.
