A substance is anhydrous if it contains no water, for example, salts lacking their water of crystallisation.

Fat free mass (muscle) is a good conductor as it contains a large amount of water (approximately 73 ) and electrolytes, while fat is anhydrous and a poor conductor of electric current.

It is seen in ice at high pressure (Ice X), and also in the solid phase of many anhydrous acids such as hydrofluoric acid and formic acid at high pressure.

Far from providing immunity against evolutionary pressures, culture often creates new ones. For example, the genes associated with digestion of lactose are more prevalent in populations that have traditionally bred cattle and consumed milk.

Furthermore, the inclusion of milk as a group unto itself implies that is an essential part of a healthy diet, despite the many people who are lactose intolerant or choose to abstain from dairy, and a number of cultures that have historically consumed little if any dairy products.