Intrasexual male dimorphism and alternative mating tactics: a multidisciplinary approach

• Grant number: 21/00915-5
• Support Opportunities: BIOTA-FAPESP Program - Regular Research Grants
• Duration: August 01, 2021 - October 31, 2024
• Field of knowledge: Biological Sciences - Zoology - Animal Behavior
• Principal Investigator: Glauco Machado
• Grantee: Glauco Machado
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated researchers: Bruno Alves Buzatto ; Fábio Santos do Nascimento ; Mercedes Burns ; Monique Nouailhetas Simon ; Solimary García Hernández

Abstract

In many animal species, some males exhibit an alternative reproductive tactic that differs from conventional tactics. For example, if the majority of males defend reproductive territories, males who exhibit an alternative tactic 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 a conventional tactic and small males (minors) who exhibit the alternative tactic. Male dimorphism associated with alternative reproductive tactics is relatively common in arthropods and, among arachnids, most cases are concentrated in the order Opiliones. The group offers a unique opportunity to advance our theoretical and empirical knowledge on the subject, because: (1) we have a good base of natural history for several species with male dimorphism; (2) many of these species are easily observed in the field; (3) there are phylogenies that allow comparative studies to be carried out; and (4) the number of researchers working with the group around the world increased a lot in the last 15 years. Therefore, we reached the necessary scientific maturity to compose an international team that use harvestmen as a study system to answer questions that are on the frontier of our knowledge on sexual selection. In general, the objective of this project will be to answer questions related to the causes and consequences of male dimorphism. The project is divided into four subprojects with complementary questions that will be answered using a multidisciplinary approach, which involves geometric morphometry, chemical ecology, molecular ecology, and comparative methods. The results that will be obtained are of interest to everyone who works with the evolution and maintenance of polymorphisms. Thus, our findings have the potential to be published in highly profile journals in the area of evolutionary biology. (AU)

Scientific publications

(4)

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

PALAORO, ALEXANDRE, V; GARCIA-HERNANDEZ, SOLIMARY; BUZATTO, BRUNO A.; MACHADO, GLAUCO. Function predicts the allometry of contest-related traits, but not sexual or male dimorphism in the amazonian tusked harvestman. EVOLUTIONARY ECOLOGY, v. 36, n. 4, p. 26-pg., 2022-02-15. (16/22679-3, 21/00915-5, 17/05283-1)

CALDART, VINICIUS MATHEUS; DOS SANTOS, MAURICIO BEUX; MACHADO, GLAUCO. Function of a multimodal signal: A multiple hypothesis test using a robot frog. Journal of Animal Ecology, NOV 2021. (21/00915-5, 15/14336-6)

MACHADO, GLAUCO; BURNS, MERCEDES. Reproductive biology of harvestmen (Arachnida: Opiliones): a review of a rapidly evolving research field. CURRENT ZOOLOGY, v. N/A, p. 21-pg., 2022-12-26. (21/00915-5)

STANLEY, ESTEFANIA; MACHADO, GLAUCO; AISENBERG, ANITA. Sexual dialogue in Pachyloides thorellii (Opiliones: Gonyleptidae): a Neotropical harvestman with much to say. JOURNAL OF ARACHNOLOGY, v. 51, n. 1, p. 11-pg., 2023-03-01. (21/00915-5)