While primary sources could include documents, objects, persons, or works of art created by a person that has witnessed or participated in an event and tries to explain it, secondary sources are texts commonly written by scholars that analyze, describe, discuss, summarize,interpret, evaluate, and process primary sources, or uses primary sources as evidence to support their points of view.
Examples of primary sources are autobiographies, diaries, personal letters, interviews, surveys, books, works of art and literature, or speeches. Examples of secondary sources could include bibliographies, history books, works of criticism and interpretation, literary reviews and magazines.
Regarding to this book, it is clear that someone has already discussed this topic before, and the author of this excerpt is only providing his own analysis on the work of other people. This conclusion can be inferred from the sentences ‘<em>these questions and problems are not new</em>’ and ‘<em>we will first provide some background information on the genetic revolution itself</em>’ Therefore, this particular text could not be relevant as a primary source as it is quoting or using primary sources.