Across natural phenomena, living organisms are unique in showing seemingly goal-oriented chemical actions which achieve self-maintenance and replication. Despite the appearance of direction, these functions are fulfilled through the random motions of molecules. The central questions of biology derive from this strange phenomenon — the emergence of “form” from “non-form.” Fungi — through displaying remarkable tolerance for aberrations in form — can be a window into basic properties of complex traits and their evolution. However, in order to make sense of “traits” in a genetic context, it is necessary to re-evaluate the assumptions we make about how life operates in general. Specifically, in asking the question “Why does this mushroom look abnormal?”, we are confronted with a more intimidating question — “How can separate individuals look the same?” To this, a common answer may claim that genes encode a “program” for the construction of forms, and by sharing the “same” genes, two individuals follow the same program. However, the genetic control of biological traits is not predetermined (Diaz et al., 2023). Rather, it is more appropriate to view similarities between individuals of a species as owing to genetic (i.e., informational) “constraints.” In mushroom-forming Fungi, loose-enough constraints on development seem to have allowed many instances of repeated evolution in reproductive forms.

Diaz, R., Wang, Z., & Townsend, J. P. (2023). Measurement and Meaning in Gene Expression Evolution. In M. Ajmal Ali & J. Lee (Eds.), Transcriptome Profiling (pp. 111–129). Academic Press.