What do you think the US would be like today had the Colonies not existed?

Had no European powers ever come to North America (which is very unlikely, since if it wasn't Britain it would've been the Spanish or the French) , the territories of the US would probably be of the native americans exclusively.

It's hard to say how the natives would've developed without any European knowledge but it's likely that the US wouldn't exist as one whole nation, but rather several tribes controlling parts of mainland US. It's also complicated to deduce if these different territories would be considered "nations".

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.

the manhattan project's indispensable man