Their is a large amount of Tiranhas, therefore the Tiranha population has the ability to rapidly multiply. There is also a variation among the population, some Tiranha's have fins and others do not.

The Tiranha's with fins will be fittest to survive, therefore they will pass down their trait of fins to the next generation, then the Tiranha's with fins in that population will survive and pass down their traits, and so on until the population only has fins because Tiranha's without fins were unfit to survive in the rainforest enviornment.

In this environment, the Tiranha's with fins are the fittest because the fins help them to quickly move through the water increasing their chances of catching food. The Tiranha's without fins lose this ability, therefore they cannot use the water as another hunting ground.

Natural Selection: Gills when in water

overproduction/variation

The Tiranha population compete for available resouces both on land and in water. They mostly are competing for food (hunting prey).

Struggle for Survival

Pass it on

Survival of the Fittest