1st Principle: Genetic Variation Seals eat a lot fish some examples are crustacean, squid, salmon, flounder, etc.
2nd Principle: Overproduction of Offspring/Struggle Although seals only have one baby per year, they still have to struggle with predators which include sharks, whales, orca, etc. Apart from that the seals tend to be really heavy making them heavier and slower therefore not letting them run away from their predators
3rd Principle: Differential Survival and Reproduction Seals who live in other types of environment or also be lighter so they can be able to move quickly but also be able to swim quicker from the predators
4th Principle: Change in the gene pool Lighter but also quicker seals will be able to survive longer increasing in the population Heavier and slower seals will decrease within the population