Ah. De-extinction. One of the most controversial and hottest topics in conservation biology right now. One I have got increasingly interested in, but one which I have serious mixed feelings about.

Also known as resurrection biology, de-extinction is the process of resurrecting species that have gone extinct. Advances in genetics, selective breeding and cloning techniques have made this a real possibility.

In 2009 it nearly happened with a Pyrenean ibex - a clone was produced using preserved tissues but it died of a lung defect just minutes after being born.

Although it would be amazing to see a woolly mammoth or passenger pigeon or one of the other candidates up for consideration for resurrection, I can't help feeling that the huge expense, expertise and attention would be much better spent on species that haven't yet gone extinct, ones that we have a real chance to save. Not to mention the ethical issues surrounding it. Controversial it is, and definitely intriguing.