A US scientist investigating the origins of the female orgasm has hit back at JK Rowling after the author appeared to pour scorn on research into the subject.
The Harry Potter writer, 51, posted a sarcastic response after reading about the scientific research carried out by two evolutionary biologists into the origins of the female orgasm.
In a paper published in the Journal Of Experimental Zoology, Mihaela Pavlicev and Gunter Wagner wrote: "In males, orgasm is invariably required for ejaculation and transfer of sperm, but in females its function is unclear."
Mother-of-three Rowling suggested that, given childbirth is so painful, its function was completely obvious.
She linked to an article in The New York Times which reported on the research being undertaken by Dr Pavlicev, from the University of Cincinnati College of Medicine, and Dr Wagner, of Yale University.
Dr Pavlicev told the Press Association that Rowling should read the paper that she and her colleague, Dr Wagner, had produced on the subject.
And she suggested that the British author appeared to have voiced her opinion on the matter without much thought.
"Our work is on the evolutionary origin of female orgasm, very much pre-dating 'the 8lb babies', and in fact pre-dating human lineage," she said.
"We make no claims about the roles that orgasm may have acquired in human lineage but these, if present, are very recent relative to the time we talk about."
Dr Pavlicev added: "Functions of the traits change in evolution and what may sound plausible opinion to us, including Ms Rowling, may not be what evolution is about.
"I think the opinion is not generated with very much thought, and I would suggest actually reading the paper might help."
The evolutionary biologist said she did not want to go "any further into this discussion" as she had put a lot of "knowledge and work" into her paper.
The New York Times article also quoted a philosopher, Elisabeth A Lloyd, who believes the female orgasm - like nipples for men - serves no evolutionary purpose and is the by-product of the development of the male orgasm.
Rowling later hinted on Twitter that she was having a bad week.