Answer:
decreased genetic difference between the two populations
Step-by-step explanation:
Gene flow involves the movement of genetic material from one population to another population of the same specie. Gene flow between two different population tend to reduce the genetic variations between the two population.
When the gene flow between the two population is very high, the two population can be considered to have the same allele frequencies, in other words, we can say they are a single population. High gene flow rate can reduce genetic differences or genetic differentiation between to two population and hence increase homogeneity.
Therefore the most predictable outcome of increased gene flow between two population is decreased genetic difference between the two populations