Aresearcher is studying two different populations of dolphins that live in two different oceans. you read the research paper, and it states that the main difference between the populations is the number of individuals in each group. what is the best summary of this finding? the two populations have the same size and age structure. this species does not vary in its population size in different areas. these two populations differ in their location and population size. the populations are in same areas but differ in population size.