The difference in appearance between males and females of the same species, beyond the reproductive organs. This can include differences in size, color, ornamentation, or body structure.
From Greek 'di-' meaning two, 'morphe' meaning form or shape, combined with 'sexual' from Latin. The term describes the two different forms that males and females can take within a single species.
In some species like anglerfish, sexual dimorphism is so extreme that scientists originally thought males and females were different species! Female spotted hyenas are larger and more aggressive than males, and even have pseudo-penises due to high testosterone levels.
Measurement and interpretation historically centered on male traits as reference; female variance was undersampled. Language presumed male size/ornamentation as 'the' dimorphism; female trait evolution was sidelined.
Describe sexual dimorphism symmetrically: specify which traits differ, in which direction, and for both sexes. Avoid defaulting male body as baseline.
["sex-biased trait evolution","phenotypic sex differences"]
Kimberly Hubbard, Fiona Crick, and others documented female weaponry and ornamentation evolution; female dimorphism is equally important to fitness landscapes.
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