In the 18th century, Carolus Linnaeus classified

organisms based on their structural similarities.

Modern classification determines relationships

more accurately because it is based on genetic

and other biochemical similarities. This change

in classification method best illustrates that

(1) multiple trials are required to increase the

validity of a scientific explanation

(2) scientific explanations are subject to the

ethical view of the scientist proposing them

(3) peer review is required to validate the results

of scientific investigations

(4) all scientific explanations are tentative and

subject to change and improvement