Why are deleterious recessive alleles difcult to purge from a population? 0 They are only selected against when common. Q They are most frequently segregate in heterozygous genotypes when rare where they are not exposed to selection. 0 They never segregate in homozygous genotypes when rare, so are not exposed to selection. Q They are only selected against when they cause a disease. The Plymouth Colony was established by ~100 English separatists in 1620 in what is current day Massachusetts, USA. Allele frequency differences in the descendent of the Plymouth colony relative to those in the larger English population are largely due to: O Mutation O Population bottleneck O Founder event O Natural selection