Hjelmen Lab @ UVU

Evolution of Sex (ALWAYS UNDER CONSTRUCTION)

BIOL 490R-1 Spring 2025

This course is co-instructed with Dr. Jessica A. Cusick

Course description:

What is sex, and why does it matter? In this discussion-based course, we will explore the complexities
and controversies surrounding the evolution of sex. From the origins of genetic sex determination and
sex chromosomes to the drama of sexual selection and reproductive behavior, we’ll take a deep dive
into the biological, ecological, and genetic factors that shape sex across the tree of life.

As an evolutionary geneticist and an evolutionary behavioral ecologist, your instructors bring varying
perspectives to unravel questions such as: Why do some species have two sexes while others defy the binary?
How do cooperation and conflict shape reproductive strategies? And why do scientists study sex
amidst its inherent ambiguity and diversity?

This course will challenge students to critically engage with the latest research, discuss emerging questions,
and reflect on the broader implications of sex in biology. Through activities and assignments, students will gain
skills in scientific literacy and communication and hopefully will leave the course with a new appreciation for the complexity of sex.

Upon completion of this course, students will be able to:

1. Discuss literature and historical figures on the topic of evolution of sex

2. Explain the genetic basis for sex determination and how mechanisms of evolution
can lead to the diversity of sex systems and behaviors

3. Describe the role of behavior in sexual biology (e.g., mating displays, reproduction),
including similarities and differences in behavior between and among sexes
4. Through the reading of scientific papers, evaluate and interpret scientific data to reach
conclusions and to use as evidence when discussing the field.

5. Discuss, write about, and present on various topics in evolutionary biology
as it relates to the evolution of sex, sex determination, and behaviors in sexual biology.

Week	Date	Topics	Assigned Readings
1	Jan. 8	Welcome and Course Introduction	How to Read and Understand a Scientific Article
2	Jan. 15	Discussion: Why Did Sex Evolve?	Ah-King and Nylin 2010: Sex in an evolutionary Perspective: Just another reaction norm
3	Jan. 22	Lecture: Evolution of Sex Chromosomes	Furman et al. 2020: Sex chromosome evolution: So many exceptions to the rules OR Bachtrog et al. 2014: Sex Determination: Why so many ways of doing it?
4	Jan. 29	Discussion: Sex Chromosomes (Lead: Group 1)	Blackmon et al. 2017: Sex Determination, Sex Chromosomes, and Karyotype Evolution in Insects
5	Feb. 5	Lecture: Sex Determination and Pathways	Capel 2017: Vertebrate sex determination: evolutionary plasticity of a fundamental switch
6	Feb. 12	Discussion: Pathways (Lead: Group 2)	Gonen et al. 2018: Sex reversal following a deletion of a single distal enhancer of Sox9
7	Feb. 19	Lecture/Discussion: Mating Systems	Clutton-Brock 1997: Mammalian mating systems
8	Feb. 26	Lecture: Sexual Selection and Sexual Conflict	Watch Pre-Recording: Sexual Dimorphism Clutton-Brock 2009: Sexual selection in females
9	Mar. 5	Discussion: Sexual Selection (Lead: Group 3)	Lipshutz 2017: Divergent competitive phenotypes between females of two sex-role-reversed species
-	Mar. 12	SPRING BREAK--NO CLASS
10	Mar. 19	Lecture: Cooperative Reproduction and Eusociality	Clutton-Brock 2002: Breeding together: kin selection and mutualism in cooperative vertebrates & Nowak et al. 2010: The evolution of eusociality
11	Mar. 26	Discussion: Cooperation (Lead: Group 4)	Krakauer 2005: Kin selection and cooperative courtship in wild turkeys
12	Apr. 2	Lecture: Flexibility in Sex and Reproduction	Vega-Frutis et al. 2014: Sex change in plants and animals: a unified perspective
13	Apr. 9	Discussion: Sex Flexibility (Lead: Group 5)	Mahmud and Struwe 2020: when the going gets tough, the tough turn female: injury and sex expression in a sex-changing tree
14	Apr. 16	Discussion: Sex Implications in Society	TBA
16	Apr. 28	Final Assignment Submissions by 11:59pm	-