Answer:
Mutations can create entirely new alleles in a population which changes the allele frequencies of a gene pool.
Answer:

Explanation:
Predators are those animals which hunt prey. Prey is the animals which is "hunted".
When the prey population is less (a decrease in prey population), There will not be more animals for "predators" to hunt and so, the competition of living will become more. Decrease in preys population would lead to a decrease in predator's population because many predators will die of hunger.
![\rule[225]{225}{2}](https://tex.z-dn.net/?f=%5Crule%5B225%5D%7B225%7D%7B2%7D)
Hope this helped!
<h3>~AnonymousHelper1807</h3>
Matching codon= CGA
Amino acid = Alanine
Yes, dolphins are mammals.