The past 50 years have seen heated debate in the reproductive sciences about global trends in human sperm count. In 2017, Levine and colleagues published the largest and most methodologically rigorous meta-regression analysis to date and reported that average total sperm concentration among men from 'Western' countries has decreased by 59.3% since 1973, with no sign of halting. These results reverberated in the scientific community and in public discussions about men and masculinity in the modern world, in part because of scientists' public-facing claims about the societal implications of the decline of male fertility. We find that existing research follows a set of implicit and explicit assumptions about how to measure and interpret sperm counts, which collectively form what we term the Sperm Count Decline hypothesis (SCD). Using the study by Levine and colleagues, we identify weaknesses and inconsistencies in the SCD, and propose an alternative framework to guide research on sperm count trends: the Sperm Count Biovariability hypothesis (SCB). SCB asserts that sperm count varies within a wide range, much of which can be considered non-pathological and species-typical. Knowledge about the relationship between individual and population sperm count and life-historical and ecological factors is critical to interpreting trends in average sperm counts and their relationships to health and fertility.
The U.S. Food and Drug Administration’s (FDA) 2013 decision to lower recommended Ambien dosing for women has been widely cited as a hallmark example of the importance of sex differences in biomedicine. Using regulatory documents, scientific publications, and media coverage, this article analyzes the making of this highly influential and mobile ‘sex-difference fact’. As we show, the FDA’s decision was a contingent outcome of the drug approval process. Attending to how a contested sex-difference fact came to anchor elite women’s health advocacy, this article excavates the role of regulatory processes, advocacy groups, and the media in producing perceptions of scientific agreement while foreclosing ongoing debate, ultimately enabling the stabilization of a binary, biological sex-difference fact and the distancing of this fact from its conditions of construction.
This article examines the work of conservation photographer Krista Schlyer who documented the impact of the U.S.-Mexico border wall on people, wildlife, and the land between 2009 and 2012. While scholars in the environmental humanities have previously analyzed literary and artistic representations of the U.S.-Mexico borderlands, this is the first analysis of how conservation photography portrays biodiversity in the borderlands. I analyze Schlyer’s works including Continental Divide (2012), a collection of photography, and Ay Mariposa (2019), a documentary film, in the historical context of the controversy concerning the environmental consequences of border wall construction that escalated during the 2016 election cycle and under the Trump administration. I argue that Schlyer’s work depicts the intersection of cultural and biological diversity in the borderlands in such a way as to unsettle and transcend oppositions of nature-culture and human-animal. These findings have implications for cultural productions that advocate for social and environmental justice.
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