Select from:
(1). animals;
(2). mammals;
(3). humans;
(4). plants;
(5). goats;
(6). offspring;
(7). Species;
(8). alleles;

Fact 1: Gene flow occurs when individuals move into or out of a population. Fact 2: Populations Populations are subsets of a species. Given the two facts above, gene flow occurs when individuals move into or out of a subset of a what?
Answer:
(7).