Why did the bronze age civilization need to develop systems of writing?

In the supreme court’s decision in korematsu v. united states, the court said that korematsu

This term, coined by john o’sullivan in 1939, represented the belief that god had preordained the u.s. to settle the whole continent and spread its influence and culture there a.) women’s suffrage b.) the industrial age c.) manifest destiny d.) the abolition movement

Some organisms have a large geographic range. for example, the norway rat lives on every continent except antarctica. a population of norway rats is the number of rats in one particular area. do you think it’s scientifically possible for a population of norway rats in north america to carry different genetic mutations than a population of norway rats in africa? do you think it’s possible that they carry some of the same mutations? what types of information can scientists learn by studying the genomes of these two populations of rats?