Gary Clark
Evolutionary biologist and paleoanthropologist
Gary Clark is an evolutionary biologist and paleoanthropologist whose career spans fossil anatomy, sexual dimorphism and fieldwork in Australia. A self-described leftist, he challenges the assumption that acknowledging biological sex is a conservative position — a distinction the Cass Review implicitly demanded of NHS clinicians and that Britain's schools debate urgently needs.
Gary Clark is an evolutionary biologist and paleoanthropologist whose career spans fossil anatomy, the study of sexual dimorphism in early hominids, and extended fieldwork with Aboriginal communities in Australia. That empirical grounding — decades spent reading sex difference in bone and field observation — makes him an unusual and credible voice in Britain's post-Cass reckoning with what medicine owes its patients.
In Biology Is Right-Wing? This Leftist Scientist Begs to Differ (episode 23, July 2025), Clark joined hosts Stella O'Malley, Mia Hughes, and Dr Bret Alderman to challenge a damaging conflation: the idea that accepting biological sex as a real, material fact is an inherently conservative position. Clark identifies as a leftist, and he argues that ceding biology to the political right impoverishes science and abandons the patients who depend on honest, evidence-based medicine.
His argument lands with particular force in Britain. The Cass Review found that NHS gender services had drifted from standard evidentiary practice, that Tavistock GIDS had failed children who deserved rigorous clinical care, and that treatment decisions had been shaped by ideology rather than evidence. Clark's insistence that evolutionary biology must underpin clinical medicine — not political preference — echoes precisely the reform agenda the Review set in motion. The same logic extends to British schools, where teachers and governors still face acute uncertainty about how to handle discussions of sex and gender with young people.
What Clark brings to the British conversation is a corrective from an unexpected quarter: a credentialled scientist of the left willing to say that science is not partisan, and that pretending otherwise causes measurable harm. For clinicians, policymakers and parents navigating the landscape after Tavistock, that reframing is both timely and necessary.
