Animals that have successfully fought to get food or mates become increasingly ferocious. this best illustrates that aggression is influenced by what factors?

According to sources, the most probable answer to this query is the selection factors. Selection factors are those that are of the environment that causes organisms to adapt for them to survive. Thank you for your question. Please don't hesitate to ask in your queries. 

I'm going to go with 1,982 feet because of all of the ice.                                               ps its this is not the answer go with d 6,500.

Yes, they are always very triggered