something, for example a gene, substance, or feature, that shows that a particular biological process or condition is present

The goal of the study was to find a biosignature that would enable the detection of Alzheimer's disease before the onset of clinical symptoms. 这项研究的目标是找到一种生物特征，以便能够在临床症状出现之前检测出阿尔茨海默氏症。

something, for example a chemical element, substance, or feature, that shows the past or present existence of living things in a place

Oxygen is a major biosignature in the search for life outside the Earth. 氧气在寻找地球外生命时被用作主要的生命迹象。

The space mission plans to detect O₂ or its product O₃ as a biosignature of life.