The rateof divergence for Z or X chromosomes is usually observed to be greater than autosomes, but the proposed evolutionary causes for this pattern vary, as do empirical results from diverse taxa. Even among moths and butterflies (Lepidoptera), which generally share a single‐origin Z chromosome, the handful of available studies give mixed support for faster or more adaptive evolution of the Z chromosome, depending on the species assayed. Here, we examine the molecular evolution of Z chromosomes in two additional lepidopteran species: the Carolina sphinx moth and the monarch butterfly, the latter of which possesses a recent chromosomal fusion yielding a segment of newly Z‐linked DNA. We find evidence for both faster and more adaptive Z chromosome evolution in both species, although this effect is strongest in the neo‐Z portion of the monarch sex chromosome. The neo‐Z is less male‐biased than expected of a Z chromosome, and unbiased and female‐biased genes drive the signal for adaptive evolution here. Together these results suggest that male‐biased gene accumulation and haploid selection have opposing effects on long‐term rates of adaptation and may help explain the discrepancies in previous findings as well as the repeated evolution of neo‐sex chromosomes in Lepidoptera.

Sperm are among the most variable cells in nature. Some of this variation results from nonadaptive errors in spermatogenesis, but many species consistently produce multiple sperm morphs, the adaptive significance of which remains unknown. Here, we investigate the evolution of dimorphic sperm in Lepidoptera, the butterflies and moths. Males of this order produce both fertilizing sperm and a secondary, nonfertilizing type that lacks DNA. Previous organismal studies suggested a role for nonfertilizing sperm in sperm competition, but this hypothesis has never been evaluated from a molecular framework. We combined published data sets with new sequencing in two species, the monandrous Carolina sphinx moth and the highly polyandrous monarch butterfly. Based on population genetic analyses, we see evidence for increased adaptive evolution in fertilizing sperm, but only in the polyandrous species. This signal comes primarily from a decrease in nonsynonymous polymorphism in sperm proteins compared to the rest of the genome, suggesting stronger purifying selection, consistent with selection via sperm competition. Nonfertilizing sperm proteins, in contrast, do not show an effect of mating system and do not appear to evolve differently from the background genome in either species, arguing against the involvement of nonfertilizing sperm in direct sperm competition. Based on our results and previous work, we suggest that nonfertilizing sperm may be used to delay female remating in these insects and decrease the risk of sperm competition rather than directly affect its outcome.

Objectives: Our goal was to explore prenatal practices and birthing experiences among Black women living in an urban North Florida community.Design: Non-random qualitative study.Setting: Private spaces at a convenient loca­tion selected by the participant.Participants: Eleven Black women, aged 25-36 years, who were either pregnant or had given birth at least once in the past five years in North Florida.Methods: Semi-structured interviews were completed in July 2017, followed by the­matic analysis of interview transcripts.Results: Four main themes emerged: a) decision-making strategies for employ­ing alternative childbirth preparation (ie, midwives, birthing centers, and doulas); b) having access to formal community re­sources to support their desired approaches to perinatal care; c) seeking advice from women with similar perspectives on birthing and parenting; and d) being confident in one’s decisions. Despite seeking to incorpo­rate “alternative” methods into their birth­ing plans, the majority of our participants ultimately delivered in-hospital.Conclusions: Preliminary results suggest that culturally relevant and patient-centered decision-making might enhance Black women’s perinatal experience although further research is needed to see if these findings are generalizable to a heterogenous US Black population. Implications for child­birth educators and health care profession­als include: 1) recognizing the importance of racially and professionally diverse staffing in obstetric care practices; 2) empowering patients to communicate and achieve their childbirth desires; 3) ensuring an environ­ment that is not only free of discrimination and disrespect, but that embodies respect (as perceived by patients of varied racial backgrounds) and cultural competence; and, 4) providing access to education and care outside of traditional work hours.Ethn Dis. 2021;31(2):227-234; doi:10.18865/ed.31.2.227

10The rate of divergence for Z or X chromosomes is theoretically predicted to be greater than autosomes, 11 but the possible explanations for this pattern vary, as do empirical results from diverse taxa. Even 12 among moths and butterflies (Lepidoptera), which generally share a single-origin Z chromosome, the 13 handful of available studies give mixed support for faster or more adaptive evolution of the Z 14 chromosome, depending on the species assayed. Here, we examine the molecular evolution of Z 15 chromosomes in two additional lepidopteran species: the Carolina sphinx moth and the monarch 16 butterfly, the latter of which possesses a recent chromosomal fusion yielding a segment of newly Z-17 linked DNA. We find evidence for both faster and more adaptive Z chromosome evolution in both 18 species, though this effect is strongest in the neo-Z portion of the monarch sex chromosome. The neo-Z 19 is less male-biased than expected of a Z chromosome, and unbiased and female-biased genes drive the 20 signal for adaptive evolution here. Together these results suggest that male-biased gene accumulation 21 and haploid selection have opposing effects on long-term rates of adaptation and may help explain the 22 discrepancies in previous findings as well as the repeated evolution of neo-sex chromosomes in 23Lepidoptera. 24 388 This project was funded by the NSF DDIG (DEB-1701931). The authors wish to acknowledge Wesley 389Mason and Michael Hulet and the rest of the Information and Telecommunication Technology Center 390 (ITTC) staff at the University of Kansas for their support with our high-performance computing. We are 391 continually grateful to Chip Taylor and Ann Ryan from MonarchWatch for access to butterflies and to 392 Clyde Sorenson for logistical and moral support in obtaining sphinx moths. Thanks, as well, to Alex 393Mackintosh and other frequenters of the Darwin Dance Hall for conversations during the interpretation 394 of these results. 395

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