[3] The book's author, Matt Ridley, is a British journalist and businessman, known for writing on science, the environment, and economics.

This chapter discusses the interplay between early geneticists, including Gregor Mendel, Charles Darwin, Hermann Joseph Muller and Francis Crick.

Ridley continues his premise in this chapter that the use of simple genetic markers is inadequate to describe the complete function of the genome, or the causation of disease.

Proof that this is wrong comes from answering the question, which of the several choices of blood typing genetic sequence is selected, since each one has different disease-resistant and evolutionary consequences?

Ridley points out the relationship between cholesterol, steroidal hormones such as progesterone, cortisol, aldosterone, testosterone and oestradiol.

Ridley describes the relationship between the development of Indo-European and other ancient root languages and the classical polymorphisms which map genetic frequencies in Eurasia.

He concludes that since the herding tribes of the world all evolved this mutation earliest, these people's genes adapted to their environment.

The controversial conclusion is that willed action can alter our evolutionary history and genetic composition, by changing the environment to which we have to adapt.

Genetic engineering has been highly controversial, especially in food production; it might, writes Ridley, one day be used in humans.

The disaster of Creutzfeldt–Jakob disease in humans was found to be caused by the PRP gene which produces a prion protein that aggregates into clumps, destroying brain cells.

Eugenics a century ago, based on faulty knowledge of genetics, led to immoral actions by governments and the US Supreme Court, pushing through compulsory sterilization of people such as those with trisomy 21 which causes Down syndrome.

I envy Ridley's talent for presenting, without condescension, complex sets of facts and ideas in terms comprehensible to outsiders.

Silver calls Ridley "adamant" in believing that the use of "personal genetics" must not be left for doctors or governments to control, following on from the mistakes of eugenics a century ago, but that it's a fundamental human right to "see and use the messages in their own DNA as they see fit."

Silver describes the book as remarkable for focusing on "pure intellectual discovery", providing "delightful stories".

[2] The biologist Jerry Coyne, writing in the London Review of Books, criticises Genome as "at once instructive and infuriating.

"[3] For example, Coyne mentions Ridley's incorrect claim that "half of your IQ is inherited";[3] that Ridley assumes that the marker used by Robert Plomin, IGF2R, is the purported "intelligence gene"[3] that it marks; and that social influences on behaviour [always] work by switching genes on and off, something that Coyne states is "occasionally true".

[3] Coyne argues that Ridley is an "implacable"[3] genetic determinist, denying the influence of the environment, and calling his politics "right-wing".

"[8] In Shermer's view, "It is a facile literary device to help readers get their minds around this illimitable subject, but I fear that it gives the wrong impression, disclaimers notwithstanding, that such things as intelligence, instinct, or self-interest are wholly located on that chromosome (and, therefore, genetically programmed and biologically determined).