Animal experts are queuing up to support the case. Professor Volker Sommer, a chimp expert at University College London, says that "It's untenable to talk of dividing humans and humanoid apes because there are no clear-cut criteria, neither biological, nor mental, nor social."

The looming debate was the occasion for some thoughtful commentary from both sides of the debate. Harvard professor Michael Sandel, a supporter of destructive embryo research, points out in the Boston Globe that President Bush's position is inconsistent. If he really does believe that embryos are human persons, surely he ought to seek to ban it completely, not merely deny it federal funding.

Austrian demographers studied Danish birth rates and concluded that with IVF included in their analysis, the birth rate was steady. Without it, it declined to below 1.8 children per woman. Since an important reason for declining birth rates is delayed child bearing, this suggests that making IVF readily available for women over 35 helps to keep the birth rate up.

However, human rights groups were sceptical of genuine improvements in China's opaque system for obtaining organs. The official news agency Xinhua maintains that most come from deceased donors who have voluntarily donated. While this may be true, in 90% of these cases, the cause of decease is a judicial execution. If so, voluntary consent is virtually meaningless, claims Nicholas Bequelin, of Human Rights Watch.

Whatever the public might feel, suggests the letter, the views of scientists should prevail: "They highlight the need for this work because of the shortage of human eggs for medical research and because they see it as a vital avenue of inquiry which could greatly increase our understanding of serious medical conditions and ultimately lead to new treatments."

Within Parliament, members of a science and technology select committee are giving hybrid embryos vigorous support. "Ministers have never provided a rational basis for their ban and their only supporters are pro-life groups and anti-science campaigners who oppose all embryo research," says MP Evan Harris.

A number of recent books support variations of this claim. There is In Gods We Trust: The Evolutionary Landscape of Religion, by anthropologist Scott Atran. Last year Newberg published Why We Believe What We Believe: Uncovering Our Biological Need for Meaning, Spirituality, and Truth. Matthew Alper also released last year a revised edition of his 1996 book The 'God' Part of the Brain: A Scientific Interpretation of Human Spirituality and God.

Growing heart valves is a big step forward in scientists' efforts to grow whole organs from stem cells. They have already grown tendons, cartilages and bladders from adult stem cells.

The increasingly messy dispute is described in the current issue of the British Medical Journal. Jeong Hwan Kim, a Korean doctor now working in Singapore, wrote a PhD on premature ovarian failure. His conclusions were published as a Korean-language paper in the Korean Journal of Obstetrics and Gynaecology in January 2004. Much to his surprise, he discovered that substantially the same paper was published in English in the leading journal Fertility and Sterility in December 2005 without his knowledge. Six authors were listed -- and he was not one of them. The leading author was his former boss, Dr Cha, and another was the head of genetics at CHA General Hospital, Sook Hwan Lee.

Without going into all the claims and counter claims, the current situation is as follows. Dr Lee is now facing criminal copyright infringement charges in Korea. Dr Cha's lawyers have accused Fertility and Sterility of defamation. The Korea journal has demanded that the American journal issue a retraction on the ground of duplicate publication. The CHA group has described Dr Kim as a bit player in the research whose email address was lost after he moved to Singapore.

The meat in the sandwich is Kwang Soo Kim, a Harvard professor who had joined the CHA research group only a short time before the scandal broke. He now has the unenviable task of both defending his colleagues and conducting his own campaign for Western standards of publication in Korea. If the issue cannot be smoothed over, a US$2.6 million research grant which CHA received from the California Institute for Regenerative Medicine is at risk.

More bad news for boys: Adult stem cells from females are more successful at regeneration than those from males, scientists at the Pittsburgh School of Medicine have found. "Regardless of the sex of the host, the implantation of female stem cells led to significantly better skeletal muscle regeneration," they wrote in the Journal of Cell Biology. ~ MSNBC.com, Apr 9