The search for extraterrestrial life centres on the search for ‘biosignatures’. Yet there is little agreement within the scientific community with respect to what exactly it is for something to be a biosignature. Existing accounts are presented and criticised. An alternative is provided that resolves problems with existing accounts by distinguishing clearly between types and tokens.

中文翻译：

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生物特征的新工作

寻找外星生命的核心是寻找“生物特征”。然而，对于生物特征到底是什么，科学界内部几乎没有达成一致。现有的账目被提出并受到批评。提供了一种替代方案，通过明确区分类型和令牌来解决现有帐户的问题。