The Role of Natural and Sexual Selection in the Origin and Maintenance of Divergence Within and Between the Mexican Sailfin Mollies, \u3cem\u3ePoecilia velifera\u3c/em\u3e and \u3cem\u3eP. petenensis\u3c/em\u3e

Understanding speciation remains a holy grail of evolutionary biology. One useful approach is studying the evolutionary mechanisms important in population divergence to infer the mechanisms important in speciation. This method is especially useful when closely related species can be compared to determine whether intraspecific differences parallel interspecific differences. I studied population divergence in two species of Mexican sailfin mollies, Poecilia velifera and P. petenensis. These closely related species are particularly useful for this type of study, as they live in habitats that may differ in the importance of natural selection. In addition, these species may differ in the importance and strength of sexual selection, as males exhibit secondary sexual morphological and behavioral traits. To understand population divergence, I compared morphology among populations in both species. In addition, I observed male mating behaviors to understand the pattern of behavioral differences among populations. Finally, I used microsatellite loci to determine neutral genetic differentiation both within and between the two species. Morphologically, I found that populations in both species were differentiated, and while some morphological trait differences were shared among populations in both species, important differences were also present. For example, caudal peduncle differences among populations in P. petenensis, but not P. velifera, suggest that habitat differences may shape some morphological differences. Males of P. velifera showed evidence of an alternative male mating strategy, with small males performing only gonopodial thrusts, while large males performed both courtship displays and gonopodial thrusts. Males of all sizes of P. petenensis performed both mating behaviors, regardless of body length. In addition, little variation existed between populations of P. velifera, however, males of P. petenensis showed more population specific rates of mating behaviors. Finally, microsatellite analysis revealed that while most populations were genetically distinct, patterns of genetic variation were not concordant with patterns of phenotypic variation, suggesting that selection, and not genetic drift, is likely promoting population divergence in P. velifera and P. petenensis. These results, taken together, suggest that differences in population divergence between these species are the results of both natural and sexual selection, which have been important evolutionary mechanisms in sailfin molly speciation

The Ursinus Weekly, October 3, 1974

Statistics prove rumor unfounded • WRUC FM hits the air • New chaplain brings new ideas to U.C. • Musical forum presented by Mme. Agi Jambor • Dr. Williamson authors new study of Corinthians • Editorial • Pages from Ursinus past • Alumni corner: Assurance to insurance • Summer in the city • Letter from London • S.F.A.R.C. and you • Assistant Deans of Men and Women appointed • Festival help needed • Slow boat to China • Harriers sweep Drew and Eastern • The Spirit of the 76ers • Women\u27s hockey season opens • Why Bears?https://digitalcommons.ursinus.edu/weekly/1020/thumbnail.jp

Moyo Vol. VIII N 2

Durica, Paul. Editor\u27s Letter . 4. Fisher, Dan. Heaven for Thunder (Thoughts on the Last Execution) . 5. Anshuman, Karan. Return to Sender (Mail-Order Brides Log-On Love) . 6. Grindstaff, Michelle. Madonna or Whore (Language Traps Female Sexuality) . 7. Thackeray, Alex. Strike Against the Right (Canada Collegians Take Action) . 8. Dotson, Dorothy. Tori Listening to Mullet Boy . 10. Stine, Alison. Tori Story (Secrets of a Toriphile: Good Girl Gets Plugged) . 11. Barret, Laura. Late Night Crush (Girl Crazy for Conan) . 15. Hankinson, Tom. Environmentally friendly, or Else (DURP tough on DU Junk) . 16. Bussan, David. Fantasy\u27s Island (Alums Find Paradise in Northern Cyprus) . 18. Burt, Kara. Innocents on Break (Students Exercise Alternatives in New York) . 21. Werne, Kirsten. Two Turntables and a Ten-Gallon Hat . 23. Million, Chris. Friendship a Modem Away, Sigh (AOL Alters Denison Social Scene) . 34

The Lantern Vol. 39, No. 1, Fall 1972

• A Journey Into Darkness • September 5, 1972 • Atlantic Taperecorder • Aftermath • Linda • Sweet Baby Jane • The Court of the Ebony Clown • The Cosmic Band • Poem to the Dreamer • Dawn • Too Bad Life Isn\u27t • Incident at Tiffany\u27s • Sonnet • Infinitas • Podiatry • 2 and 4a • Autistic Autumn • I Walk Alone • Eyes---and They Were Emptyhttps://digitalcommons.ursinus.edu/lantern/1101/thumbnail.jp

The Lantern Vol. 39, No. 2, Spring 1973

• Days of Rain • Reflections On Clifton, New Jersey • Interlude • Window Scene • Eh! • Odyssey of Malcolm • Tuna on Toast • The Second Avenue Bus • Salutation of the Dawn • So Say Something • Mood • Moriarty\u27s Lament • I\u27ve Been a Lonely Gypsy • Change • Cool Ray • The Thinker • A Southern Sunsethttps://digitalcommons.ursinus.edu/lantern/1102/thumbnail.jp

Female sexual preferences toward conspecific and hybrid male mating calls in two species of polygynous deer, Cervus elaphus and C. nippon

The behavioral processes at the basis of hybridization and introgression are understudied in terrestrial mammals. We use a unique model to test the role of sexual signals as a reproductive barrier to introgression by investigating behavioral responses to male sexual calls in estrous females of two naturally allopatric but reproductively compatible deer species, red deer and sika deer. Previous studies demonstrated asymmetries in acoustic species discrimination between these species: most but not all female red deer prefer conspecific over sika deer male calls while female sika deer exhibit no preference differences. Here, we extend this examination of acoustic species discrimination to the role of male sexual calls in introgression between parent species and hybrids. Using two-speaker playback experiments, we compared the preference responses of estrous female red and sika deer to male sexual calls from conspecifics versus red × sika hybrids. These playbacks simulate early secondary contact between previously allopatric species after hybridization has occurred. Based on previous conspecific versus heterospecific playbacks, we predicted that most female red deer would prefer conspecific calls while female sika deer would show no difference in their preference behaviors toward conspecific and hybrid calls. However, results show that previous asymmetries did not persist as neither species exhibited more preferences for conspecific over hybrid calls. Thus, vocal behavior is not likely to deter introgression between these species during the early stages of sympatry. On a wider scale, weak discrimination against hybrid sexual signals could substantially contribute to this important evolutionary process in mammals and other taxa

The African Cichlid Fish Astatotilapia burtoni Uses Acoustic Communication for Reproduction: Sound Production, Hearing, and Behavioral Significance

Sexual reproduction in all animals depends on effective communication between signalers and receivers. Many fish species, especially the African cichlids, are well known for their bright coloration and the importance of visual signaling during courtship and mate choice, but little is known about what role acoustic communication plays during mating and how it contributes to sexual selection in this phenotypically diverse group of vertebrates. Here we examined acoustic communication during reproduction in the social cichlid fish, Astatotilapia burtoni. We characterized the sounds and associated behaviors produced by dominant males during courtship, tested for differences in hearing ability associated with female reproductive state and male social status, and then tested the hypothesis that female mate preference is influenced by male sound production. We show that dominant males produce intentional courtship sounds in close proximity to females, and that sounds are spectrally similar to their hearing abilities. Females were 2–5-fold more sensitive to low frequency sounds in the spectral range of male courtship sounds when they were sexually-receptive compared to during the mouthbrooding parental phase. Hearing thresholds were also negatively correlated with circulating sex-steroid levels in females but positively correlated in males, suggesting a potential role for steroids in reproductive-state auditory plasticity. Behavioral experiments showed that receptive females preferred to affiliate with males that were associated with playback of courtship sounds compared to noise controls, indicating that acoustic information is likely important for female mate choice. These data show for the first time in a Tanganyikan cichlid that acoustic communication is important during reproduction as part of a multimodal signaling repertoire, and that perception of auditory information changes depending on the animal's internal physiological state. Our results highlight the importance of examining non-visual sensory modalities as potential substrates for sexual selection contributing to the incredible phenotypic diversity of African cichlid fishes

Identification of nine new susceptibility loci for endometrial cancer

Endometrial cancer is the most commonly diagnosed cancer of the female reproductive tract in developed countries. Through genome-wide association studies (GWAS), we have previously identified eight risk loci for endometrial cancer. Here, we present an expanded meta-analysis of 12,906 endometrial cancer cases and 108,979 controls (including new genotype data for 5624 cases) and identify nine novel genome-wide significant loci, including a locus on 12q24.12 previously identified by meta-GWAS of endometrial and colorectal cancer. At five loci, expression quantitative trait locus (eQTL) analyses identify candidate causal genes; risk alleles at two of these loci associate with decreased expression of genes, which encode negative regulators of oncogenic signal transduction proteins (SH2B3 (12q24.12) and NF1 (17q11.2)). In summary, this study has doubled the number of known endometrial cancer risk loci and revealed candidate causal genes for future study

Identification of nine new susceptibility loci for endometrial cancer

Endometrial cancer is the most commonly diagnosed cancer of the female reproductive tract in developed countries. Through genome-wide association studies (GWAS), we have previously identified eight risk loci for endometrial cancer. Here, we present an expanded meta-analysis of 12,906 endometrial cancer cases and 108,979 controls (including new genotype data for 5624 cases) and identify nine novel genome-wide significant loci, including a locus on 12q24.12 previously identified by meta-GWAS of endometrial and colorectal cancer. At five loci, expression quantitative trait locus (eQTL) analyses identify candidate causal genes; risk alleles at two of these loci associate with decreased expression of genes, which encode negative regulators of oncogenic signal transduction proteins (SH2B3 (12q24.12) and NF1 (17q11.2)). In summary, this study has doubled the number of known endometrial cancer risk loci and revealed candidate causal genes for future study

Effects of exclusive use of stored sperm on offspring production in the sailfin molly Poecilia latipinna

This research investigated how the first brood of Poecilia latipinna varied in size, fry characteristics, and interbrood interval when females were only able to rely on stored sperm (compared to females that were remated). Females were isolated after giving birth and then either given access to a potential mate or remain in isolation. Brood sizes, fry sizes at days 1 and 7, and inter-brood intervals were all measure