Which is a factor that likely explains the choice of the united states to be isolationist or internationalist in its foreign policy in the twentieth century?

The US’ being an isolationist or internationalist has to do something with the International law and organizations.  This had been a key element in foreign policy especially when the country deals with other economic powers such as Europe which they historically had conflicts with.

genetics is the study of how dna works, the methodologies defining the new recent technologies allow scientist to have a panoramic view of the entire dna landscape, especially how genomes interact with their environment, including off course, factors outside their organisms.

thus is very possible the existence of both scenarios, where populations of isolated individuals have different genetic traits, and share traits related to genetic mutation, due rats can easily travel overseas using human transport channels. so scientists could get a vast number of data, including human interaction, evolution of rodents, health development, spread of infections, development of new organisms, how genomes evolve in different environments and so on.

i need the diagram.