[ **up: [[Biology]]** ] --- # Sex (Biology) > [!info] Note: **[[Gender vs. sex]]** --- + [[Gonochorism|Gonochorism]] + [[Intersexuality|Intersex variations]] + [[Hermaphroditism]] - [[Sequential hermaphroditism]] - [[Simultaneous hermaphroditism]] - [[Systems with more than two sexes (Biology)]] > [!tip] > - [[2024-0419. 'Endosex' is the state of individuals born with the sexual anatomy, reproductive system, and chromosomes associated with their assigned sex.|'Endosex' is the state of individuals born with the sexual anatomy, reproductive system, and chromosomes associated with their assigned sex.]][^1] > + [[2024-0419. 'Intersex variations' is a term used to refer to a wide range of variations in sex characteristics.|'Intersex variations' is a term used to refer to a wide range of variations in sex characteristics.]][^2] > - ***Do not* call your fellow humans ‘hermaphrodites’: say [[Intersexuality|intersex]].** --- - [[Sex determination]] [[2025-0313. 'In sexually reproducing isogamous organisms, gametes (or diploid cells in ciliates) are classified into two or more groups called sexes, and mating occurs only between cells of different sexes.'|'In sexually reproducing isogamous organisms, gametes (or diploid cells in ciliates) are classified into two or more groups called sexes, and mating occurs only between cells of different sexes.']][^3] --- ## Phenotypes (Sexual Differences in Phenotype) [[2025-0313. ‘Most sex differences in phenotype are controlled by gonadal hormones … (but) sex chromosome complement can have a direct influence on the establishment of sex-specific behaviours, independently from gonads.’|‘Most sex differences in phenotype are controlled by gonadal hormones… [but] sex chromosome complement can have a direct influence on the establishment of sex-specific behaviours, independently from gonads.’]][^4] --- ## Evolution of the Sexes [[2023-0917. Sexual conflict (as male coercion) has been suggested as a possible mechanism for the maintenance of costly sexual reproduction, offering a potential resolution to the paradox of sex.|Sexual conflict (as male coercion) has been suggested as a possible mechanism for the maintenance of costly sexual reproduction, offering a potential resolution to the paradox of sex.]][^5] [[2024-0602. The costs and limitations of female resistance can be key factors in the maintenance of sexual reproduction; males ability to overcome female resistance can turn sex into an evolutionary trap.|The costs and limitations of female resistance can be key factors in the maintenance of sexual reproduction; males ability to overcome female resistance can turn sex into an evolutionary trap.]][^6] --- ### Searching & non-searching phenotypes > male & female [[2025-0321. 'When mate search is efficient, disruptive frequency-dependent selection on time allocation to mate search leads to the evolution of searching and nonsearching phenotypes and, ultimately, to the evolution of males and females.'|'When mate search is efficient, disruptive frequency-dependent selection on time allocation to mate search leads to the evolution of searching and nonsearching phenotypes and, ultimately, to the evolution of males and females.']][^7] --- ## Note re. Sex in Animals re. Humans [[2025-0313. '... animals don’t have a sense that they are acting male or female.'|'... animals don’t have a sense that they are acting male or female.']][^8] [^1]: ‘Endosex’, *[['Homosaurus - An International LGBTQ+ Linked Data Vocabulary' (website)|Homosaurus: An International LGBTQ+ Linked Data Vocabulary]]* updated 28 February 2022, https://homosaurus.org/v3/homoit0001896 [^2]: ‘Intersex variations’, *[['Homosaurus - An International LGBTQ+ Linked Data Vocabulary' (website)|Homosaurus: An International LGBTQ+ Linked Data Vocabulary]]*, updated 8 December 2021, https://homosaurus.org/v3/homoit0000669. [^3]: Yoh Iwasa and Akira Sasaki, ‘[[Iwasa & Sasaki. ‘Evolution of the number of sexes’, 1987.|Evolution of the number of sexes]]’, *Evolution* 41, Issue 1, 1 January 1987, p.49. [^4]: P. A. Saunders, et al., ‘[[Saunders, et al. ‘Masculinised behaviour of XY females in mammal with naturally occurring sex reversal’, 2016.|Masculinised behaviour of XY females in a mammal with naturally occurring sex reversal]]’, *Scientific Reports*, vol. 6 (11 March 2016), p. 1. [^5]: Nathan W. Burke and Russell Bonduriansky, ‘[[Burke & Bonduriansky. ‘Male Coercion, Female Resistance and the Evolutionary Trap of Sexual Reproduction’, 2017.|Male Coercion, Female Resistance and the Evolutionary Trap of Sexual Reproduction]]’, *bioRxiv* (5 June 2017), p. 146076. [^6]: Nathan W. Burke and Russell Bonduriansky, ‘[[Burke & Bonduriansky. ‘Male Coercion, Female Resistance and the Evolutionary Trap of Sexual Reproduction’, 2017.|Male Coercion, Female Resistance and the Evolutionary Trap of Sexual Reproduction]]’, *bioRxiv* (5 June 2017), p. 146076. [^7]: Nelson R. Cabej, ‘[[Cabej. ‘Epigenetics of Reproduction in Animals’, 2013.|Epigenetics of Reproduction in Animals]]’, in *Building the Most Complex Structure on Earth* (Elsevier, 2013), p. 101. [^8]: Paul Vasey, in Amanda Leigh Mascarelli, ‘[[Leigh. ‘Explainer_ Male-female flexibility in animals’, 2015.|Explainer: Male-female flexibility in animals]]’, *ScienceNewsExplores*, 31 July 2015, https://www.snexplores.org/article/explainer-male-female-flexibility-animals.