OPINION: Few acts in the living world involve more intimate cooperation than sex. Two individuals combining their DNA to create a new and unique individual. And that’s only conception. In long-lived species, especially our own, it can take decades of hard cooperative work to raise a family.

But the mirror-twin of this capacity for self-sacrificing parental cooperation is an inherent susceptibility for conflict. Regular readers of this column will recognise a common theme: females and males in general, and women and men in particular, tend to differ in their evolutionary interests. From whether or not to mate, how many offspring to bear, how long to care for them before weaning or kicking them out, and whether to begin the whole business over again, what’s good for the goose isn’t always what’s good for the gander.

When you research and write about sexual conflict for a living, the newspapers look a whole lot different. Conflict between women and men pervades every sphere of human life. Here are a few stories that caught my attention this week:

  • Distinguished surgeon Lamar Greenfield, resigned as editor of Surgery News and as president-elect of the American College of Surgeons after commenting, with reference to published research, about the possible effects of semen in reducing depression. In a fit of creativity, the American press have dubbed the affair “Semengate”.
  • The United Arab Emirates passed a law compelling mothers to breastfeed their children for two years, denying mothers the agency to make this crucial childcare decision.
  • Sydney mother Comrie Cullen was violently killed, found dead near her car. Her estranged husband, Christopher Cullen, against whom she had an apprehended violence order, was found in mangroves nearby with cuts police say were “consistent with being self-inflicted”.
  • The history of Jude Law and Sienna Miller’s mutual infidelity got dragged into the light again, at the phone hacking trial of Andy Coulson and Rebekkah Brooks.
  • The world’s most prominent feminist thinker, Beyoncé, performed Drunk in Love alongside her husband Jay-Z to open the Grammy’s. Her racy outfit and Jay-Z’s grabbing of his own crotch throughout set off conservative New York Post columnist Naomi Schaeffer Riley, who criticised Jay-Z as ‘a poor excuse for a husband’. Think Progress' Alyssa Rosenberg reckons conservatives should be grateful for the Knowles-Carter union, as Beyoncé and Jay-Z might just be the best advertisement for marriage in contemporary America.

These stories lurch between absurdity and utter tragedy. But they, and others like them, compel our attention because they concern the central dilemma of sex and relationships: the differing interests of the partners – or potential partners – involved.

These are the differences of interest that romantic love evolved to ameliorate, however imperfectly. They are the dark force that animates great art, from Thesmophoriazusae to Madame Bovary, and from Carmen to Breakfast at Tiffany’s.

Economists, too, are fascinated by the push-pull of cooperation and conflict over sex, reproduction and family life. Which is why, this week, Jason Collins, some colleagues at UNSW’s Evolution & Ecology Research Centre, and I are hosting an exciting mix of evolutionary biologists, economists and social scientists to discuss our research on these complex issues.

I hope, in the coming weeks to post about some of the talks at the conference, and the connections made. In the mean time, Sydneysiders interested in these issues might enjoy either of two public lectures that are happening as part of the conference.

Rob Brooks is a professor of evolution at UNSW and author of Sex, Genes & Rock'n'Roll: How Evolution Has Shaped the Modern World. He is the winner of the 2013 Eureka Prize for promoting understanding of Australian science research. Twitter: @Brooks_Rob

This piece was first published in The Conversation.