Women of child-bearing age steadily run out of eggs by the continuous process of cell death. While reading a copy of the 'Guardian' carefully from cover to cover, a normal woman will have lost on average two eggs - while, typically, a normal man will have made 70,000 new sperm.
Following 25 children for the TV series 'Child of Our Time' has been extraordinary. The BBC's original plan was to commemorate the new millennium. What better way than to film a number of expectant mums from across the U.K.? Coming from widely different backgrounds, all were due to give birth on January 1, 2000.
Much as I like and admire Richard Dawkins, I do think that to call a book 'The God Delusion' is very worrying because the title implies that if you don't believe in what I believe then you are 'deluded.' That, I think, is a dangerous concept and one that is unlikely to win hearts and minds.
I used to work for the World Health Organisation in poor countries all over the world - Bangladesh, Korea, the Philippines and India. You learn a whole range of things about how other people are living and try to connect with them to gain an understanding of where they're coming from.
Man is a competitive creature, and the seeds of conflict are built deep into our genes. We fought each other on the savannah and only survived against great odds by organising ourselves into groups which would have had a common purpose, giving morale and fortitude.
Childhood depression tends to be more common in inner cities, being most frequently related to serious social deprivation, bullying, domestic violence, wartime experience and famine. It is, for example, a serious problem among children who are traumatised refugees.
You can't be judgmental about babies. They are all have different needs. I was left with an enduring hatred of cheese because it was forced down me when I was young.
I don't believe in regretting - one should try to move on. My mum was good at that. She was deeply in love with my father, and he died when I was nine. She remarried, and her second husband died, too. I saw the grieving process she went through. My mother had this way of moving on. It was a fine trait.
We must not fail to recognise that television can be a hugely positive influence in children's lives, one of the greatest educators in contemporary society and an increasing influence on all the children followed in 'Child of Our Time.'
In reality, both religion and science are expressions of man's uncertainty. Perhaps the paradox is that certainty, whether it be in science or religion, is dangerous.
Some people, both scientists and religious people, deal with uncertainty by being certain. That is dangerous in the fundamentalists and it is dangerous in the fundamentalist scientists.
We live longer and healthier lives than ever before. Animal research has improved the treatment of infections, helped with immunisation, improved cancer treatment and had a big impact on managing heart disease, brain disorders, arthritis and transplantation.
Nearly all inventions are not recognised for their positive side either when they're made. So, for example, scientists didn't go out to design a CD machine: they designed a laser. But we got all sorts of things from a laser which we never remotely imagined, and we're still finding things for a laser to do.
About 3 million IVF babies have been born since Louise Brown's birth in 1978. Bizarrely, when this life-giving treatment was first considered, it was massively controversial. A storm of vitriolic protest came from many religious leaders, journalists, politicians, regrettably even other scientists and doctors.
We give antibiotics to people when they're dying or when they're not well; that's acting God. I mean, acting God is using the tools of creation to try and improve human life, human existence. I don't think that that's a huge problem.
Both in Britain and America, huge publicity has been given to stem cells, particularly embryonic stem cells, and the potential they offer. Of course, the study of stem cells is one of the most exciting areas in biology, but I think it is unlikely that embryonic stem cells are likely to be useful in healthcare for a long time.
Now we have technology where we can modify the genomics of individuals by gene transfer and genetic meddling, we may find that people will want to modify their children, enhance their intelligence, their strength and their beauty and all the other so-called desirable characteristics.
Animal rights activists talk about cruelty and torture, some backing their assertions by publishing out-of-date photographs of 'experiments' banned long ago. This is a misrepresentation. The work we do is performed with compassion, care, humanity and humility. I have never seen an animal suffer pain.
We must not confuse religion with God, or technology with science. Religion stands in relationship to God as technology does in relation to science. Both the conduct of religion and the pursuit of technology are capable of leading mankind into evil; but both can prompt great good.
I remember eating in school in the years after the Second World War. Most of my friends had miserable portions of Spam with an inedible, glutinous pudding served in containers we called 'coffins.' As a vegetarian, I had a lump of loathsome cheese and some bread.