Anisogamy: The Beginning of Male and Female #509

January 18, 2019

This week we discuss how the sperm and egg came to be, and how a difference of reproductive interest has led to sexual conflict in bed bugs. We'll be speaking with Dr. Geoff Parker, an evolutionary biologist credited with developing a theory to explain the evolution of two sexes, about anisogamy, sexual reproduction through the fusion of two different gametes: the egg and the sperm. Then we'll speak with Dr. Roberto Pereira, research scientist in urban entomology at the University of Florida, about traumatic insemination in bed bugs.


  • Geoff Parker
  • Roberto Pereira
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Guest Bios

Geoff Parker

Geoff Parker studies the evolutionary biology of reproduction and sexuality, behaviour, and life histories. Early in his career, most ethologists and ecologists interpreted adaptations in terms of 'survival value to the species'. His early work on the dung fly mating system strove to make quantitative analyses of behaviour patterns in terms of selective benefits accruing to individuals. Around the same time, a handful of others were also engaged in research with similar focus; this had coalesced by 1974-8 into the discipline now known as behavioural ecology. His most important contributions in evolutionary biology include a theory for why there are two sexes, the first formal analysis and definition of sexual conflict, identification and development of sperm competition and post-copulatory sexual selection, and early theories of contest behaviour and animal distributions. Most recently, his work centers on the evolution of complex life cycles in helminths, and on development of an evolutionary theory for sequential transitions in sexual strategy (the 'sexual cascade'). He is now retired, but continues research.

Roberto Pereira

Roberto Pereira is an entomologist with a B.S. degree in Agriculture from the University of Sao Paulo, Brazil, a M.S. degree from Cornell University, and a Ph.D. degree from the University of Florida. Earlier in his career, Roberto worked on insect pathology and microbial control and served as the coordinator for large scale projects on "Area-wide Suppression of Fire Ants in Pastures" and "Deployed War-Fighter Protection". Roberto now serves as a Research Scientist at the Urban Entomology Lab at the University of Florida, where he conducts research, educates, and runs extension activities in several areas of urban entomology. His work involves ants, cockroaches, termites, bed bugs, flies, mosquitoes, and other pests. Roberto has authored or coauthored 96 scientific publications, 22 book chapters, 19 US and international patents on pest control, and numerous non-refereed and trade journal publications. He currently serves as Managing Editor for PestPro Magazine, is a member of the Society for Invertebrate Pathology, the Entomological Society of America, the Entomological Society of Brazil, and the Florida Entomological Society.