Recessiveness is the target here, since recessive alleles often code for proteins that don’t work properly, if at all.
For instance, Mendel’s original tall-short alleles were a "normal" growth hormone allele, and an allele that produced a non-functioning version. With one OR two alleles present, growth hormone is produced and the plants grew to normal height; with two recessive alleles, no working growth hormone was made and the plants were very short.
Its like that only …only thing is that we dont call it evolution/adaptation..we call it dominance!
Accordin to Hardy Weinberg equalibrium the removal of allele needs a lot of time and it is impossible in Natural Populations hence onlt recessive gets survived ( in the form of Heterozygots also)…