The Sexual Evolution: How 500 Million Years of Sex, Gender, and Mating Shape Modern Relationships

“When it comes to a more expansive, diverse, and flexible attitude toward gender and sexuality, we can learn a lot by looking beyond our own species,” according to this enthralling survey. Lents (Human Errors), a biology professor at John Jay College, CUNY, explains that same-sex intercourse is extremely common in the animal kingdom, noting, for instance, that female bonobos have sex with each other more often than with males as a form of bonding and social climbing. Many species have more than two ways to express gender (loosely construed as “patterns of behavior that are either sexualized or tied to reproduction”), Lents contends, discussing how male bluegill sunfish come in two biologically distinct types, the smaller of which resembles a female and engages in three-way mating rituals with larger males and females. Elsewhere, Lents emphasizes how few animals practice sexual monogamy, explaining how couplings among birds were long assumed to equate with sexual exclusivity until genetic testing in the late 1980s revealed the high prevalence of hatchlings sired by a male other than their mother’s partner. Lents gleefully tears down cis, hetero, and monogamous norms, outlining surprising case studies that give the lie to restrictive conceptions of gender and sex. The result is an indispensable glimpse into the queerness of animals. Agent: Larry Weissman, Larry Weissman Literary. (Feb.)