Mutation and the Tree of Life

 Mutation: is the change to a living organism's DNA that can be detrimental, neutral, or helpful to the organism's chances of survival 

In this population of monsters, a mutation occurred in a base that changed the amino acid that codes for a protein that controls how many horns are on the top of a monster's head. 

    This point mutation added an extra horn to the top of the monsters with this mutation's head. 

Mutations can be either beneficial, neutral, or harmful. In the case of this population, an extra horn would become beneficial if the monsters suddenly needed to fight off predators. Having an extra horn would allow the monster to have an additional weapon of sorts. This mutation would remain neutral if nothing in the monster's happy environment changed, and they did not have any competition for mates or resources. Finally, this mutation could become harmful to the population if monsters with two horns would only mate with those also with two horns which could lead to a decrease in population size. 

A beneficial mutation would increase the population's size as more would survive and be able to reproduce due to surviving predators. This means that the population would continue to evolve with more monsters having 3 horns. A neutral mutation would not affect the population's number of monsters with 3 horns as it does not offer an evolutionary advantage. A harmful mutation would mean the population would evolve to continue to have the majority of 2 horned monsters and the lack of mating with 3 horned monsters would mean fewer and fewer are born with the mutation for 3 horns.