The right answer for the question that is being asked and shown above is that: (1) removing metabolic wastes from the body; (2) urea is not soluble in water; (3) simple diffusion across the skin; (4) They both actively pump salt across their gills; (5) <span>They both produce lots of diluted urine."</span>
An error is that the scientist did not control their variables. They had one group of people playing the game at 6, and another group playing at 12. This means that other things might have affected the scores other than what was being tested, which was caffeine.
I remember back in 10th grade I learned that birds that had beaks that were easier to break the seeds carried those traits to their babies and the whole area had that type of beak since it was necessary to break some seeds. So the beaks that were a disadvantage no longer existed and the beaks that became an advantage passed along to all the other birds.
Side note: if they all had the same beak they could all fight for the same type of seeds and probably have some sort of intense competition but idk if that’s necessary