Principle 2: Overproduction and the struggle to survive
Principle 3: Different survival and reproduction ( Survival of Fittest)
There are many types of jellyfish ,some that sting and some that dont . The moon jellyfish has a sting that is not able to penetrate through the skin causing no probable harm , although if a mutation were to occur there is a chance that the jellyfish could have a stronger sting . (blue one less strong one , maroon red one is the one with stronger sting ).
Principle 4: Change in the gene pool
Jellyfish tend to eat other species of jellyfish. The struggle for moon jellyfish to survive are other jellyfish seeing them as prey . ( they also get seen as prey by sharks ,tuna, &swordfish .)
The jellyfish with the stronger sting would be best fit for the adaption because they wouldn't be seen as prey by predators while the one with the weaker sting , the moon jellyfish would not survive .
if a jellyfish "couple" were to have babies and all of them were to survive and the trait they all caried was the stonger sting then the only gene in the gene pool that would be left is the stronger gene