Pre and post copulatory processes in harvestmen with male dimorphism and alternative reporductive tactics

• Grant number: 21/03200-7
• Support Opportunities: Scholarships in Brazil - Doctorate
• Effective date (Start): August 01, 2021
• Status: Discontinued
• Field of knowledge: Biological Sciences - Ecology
• Principal Investigator: Glauco Machado
• Grantee: Diego Esteban Solano Brenes
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated scholarship(s): 23/17564-6 - Does directional selection on fighter males have correlated effects on the scrambler male phenotype of bulb mites?, BE.EP.DR

Abstract

In many animal species, some males exhibit an Alternative Reproductive Tactic (ART) that differs from conventional tactics. For example, if most males defend reproductive territories, males that exhibit ARTs can act as satellites or even mimic females to invade such territories. When more than one reproductive tactic is successfully employed by males in a population, disruptive selection can favor the evolution of male dimorphism, which implies the presence of two discrete morphs: large males (majors) who exhibit conventional tactics and small males (minors) that exhibit ART. Male dimorphism associated with ARTs is relatively common in arthropods and, among arachnids, most cases are concentrated in the order Opiliones. The group, therefore, offers an unique opportunity to advance our empirical knowledge on several unanswered questions, such as: (I) how do minors circumvent the territorial custody of majors to gain access to females (pre-copulatory intrassexual selection)?; (II) does the quantity and/or quality of sperm differ between morphs (post-copulatory intrassexual selection)?; (III) are larger majors preferred by females (pre-copulatory intersexual selection)?; (IV) do females bias the offspring's paternity according to the identity of the morphs (post-copulatory intersexual selection)? The general objective of this project is to fill these knowledge gaps and, for this, the proposal is divided into four subprojects, each focused on a type and on a particular moment in which sexual selection takes place. The questions proposed here will be answered using a multidisciplinary approach that involves Chemical Ecology, comparative phylogenetic methods, paternity data and computational modeling. The results that will be obtained are of general interest to researchers working with sexual selection and, therefore, have the potential to be published in highly visible journals in the areas of Behavioral Ecology and Evolutionary Biology. (AU)