Out of the 20 most common amino acids, proline appears with a frequency of about 5%.
So, if a peptide were to be made up of a completely random assortment of the 20 most common amino acids, proline would appear about 5 times in 100 amino acids.
Because as natural selection occurs and species mate and create offspring this leads to a change in DNA which can lead to new species or evolutionists versions of that species
Bears hibernates during winter
