Mark each statement if it correctly describes events that led to the fall of rome.
a. the eastern empire gained strength while the western empire grew weaker.
b. invasions along the borders of the empire created chaos.
c. the roman army was strong, but was still unable to defend rome from the visigoths.

The answer is in fact A and B the person above me is completely correct and should have better ratings!

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.