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AbstractMany initiatives attempt to smooth transitions between 2-year colleges and 4-year universities, but retention and graduation rates for transfer-students are still low, especially in STEM. The Transfer-student Research and Integration Program (TRIP) at the University of Central Florida was developed to meet the needs of a diverse transfer population. TRIP alleviates attrition of life sciences students by providing research experiences, professional development, community integration, and mentorship. We review the model design and share early successes including higher retention rates versus comparison groups. Students reported benefitting from the skills and experiences gained and indicated TRIP’s positive impact on their STEM success and career growth. Given the quantitative and qualitative results, our model could be a template for universities attempting to improve STEM transfer-student outcomes.

How natural selection facilitates sexually dimorphic evolution despite a shared genome is unclear. The patrilineal inheritance of Y-chromosomes makes them an appealing solution. However, they have largely been dismissed due to their gene-poor, heterochromatic nature and because the additive genetic variation necessary for adaptive evolution is theoretically difficult to maintain. Further, previous empirical work has revealed mostly Y-linked sign epistatic variance segregating within populations, which can often impede adaptive evolution. To assess the evolutionary impact of Y-linked variation, we established replicate populations in Drosophila simulanscontaining multiple Y-chromosomes (YN populations) or a single Y-chromosome variant (Y1 populations) drawn from a single population. We estimated male and female heritabilities for several traits known to be influenced by Y-chromosomes, including the number of sternopleural bristles, abdominal bristles, sex comb teeth, and tibia length. A decrease in YN heritabilities compared with Y1 would be consistent with Y-chromosome variation being sign epistatic. A decrease in Y1 heritabilities would be consistent with Y-chromosome variation being additive, though additive-by-additive epistatic variation cannot be entirely dismissed. Female heritability estimates served as controls and were not expected to differ. We found male Y1 populations exhibited lower heritabilities for all traits except tibia length; consistent with Y-linked additivity (on average YN trait heritabilities were 25% greater than Y1). Female estimates showed no difference. These data suggest Y-chromosomes should play an important role in male trait evolution and may even influence sexually dimorphic evolution by shaping traits shared by both sexes.