[2] Presence of cholestane, its derivatives and related chemical compounds in environmental samples is commonly interpreted as an indicator of animal life and/or traces of O2, as animals are known for exclusively producing cholesterol, and thus has been used to draw evolutionary relationships between ancient organisms of unknown phylogenetic origin and modern metazoan taxa.

Cholesterol is responsible for membrane rigidity and fluidity, as well as intracellular transport, cell signaling and nerve conduction.

Embryophytes generally produce a variety of sterols, which are collectively known as phytosterols,[11] and cholesterol remains a minor component.

In contrast, bacteria produce other cyclic triterpenoids such as hopanoids and their diagenetic products hopanes are utilized as bacterial biomarkers.

This process occurs without the loss or gain of carbon atoms and therefore can serve as an indicator of the original steroid produced by the organism in the environment.

This measurement is done by extraction of the steranes into a non-polar solvent (e.g., dichloromethane or chloroform) and purified into a “saturates” fraction using silica gel column gas chromatography.

δ13C values of cholestane reflect the carbon isotope composition of the animals that created the original cholesterol molecules.

[14] Presence of cholestane does not necessarily indicate presence of animals, but is often used in conjunction with other biomarkers to note the rise of distinct taxa in the fossil record; with regard to this, a study measured relative abundance in cholestane versus other triterpenoid biomarkers to demonstrate the rise of algae during the Neoproterozoic.

[7][18] Tracing the actual origins of cholestane within the fossil record is challenging, as most of the rocks from that time period are heavily metamorphosed and thus potential biomarkers are thermally altered.