Navigating the Semantic Labyrinth of “Sex” in the Study of Reproductive Trait Evolution

"Sex" is a compound of many different concepts that contribute to a multiplicity of meanings. As a result, "sex" appears in a wide range of scientific research for different purposes, from describing a process of recombination and cell division to systems of categorising individuals. Identifying the meaning of "sex" in any particular context requires understanding the construction of contributing component concepts and their relationship with one another. We offer the metaphor of a labyrinth to describe the process of interpreting the meaning "sex" and uncovering its context-dependent purpose. In this way, the meanings of "sex" related to "sexual reproduction", "sex types", "sex determination", and/or "sexual systems" can be elucidated by identifying how these concepts relate to suppositions about what properties of "recombination, "meiosis", "syngamy", or "gametes" are present and to which aspects of a trait, individual, or lineage they apply. By denoting "sex" and related terminology within quotation marks, we emphasise the contextualism of language in the theory and practise of research and resultant knowledge about the natural world. The structure of a labyrinth reflects the incredible capacity of "sex" to describe the diversity and disparity of eukaryotic reproductive strategies. The analytical framework of the labyrinth highlights that different conceptual versions can arise in the consideration of reproductive trait evolution based on the relationships among concepts. Through a critical evaluation of the concepts that contribute to the labyrinth of "sex" across biology, we gain a more nuanced appreciation for the operation of "sex" within scientific knowledge.