Can modern genetic techniques make new species?

We put this to Professor Martin Bobrow from Cambridge University and Veronica van Heyningen, Professor of Genetics at Edinburgh University...

Martin - I think it's mind blowing that one can take a gene which performs a certain function in yeast and put it into a human cell and it still works. However, does that mean that we can make new species? I think the answer to that probably at the moment is not by quite a long shot. 

Veronica - Combining eggs and sperm from different species very rarely works except for closely related species like horse and donkey which can mate together and form a novel hybrid animal known as a mule. Mules can develop to birth and survive to adulthood, but they are not fertile. The mixed horse and donkey chromosomes can't produce viable eggs and sperm.

A sheep cannot be crossed to the kangaroo because even if we had sperm and eggs available, we would not succeed in making hybrid animals by in vitro fertilisation or IVF because development requires two sets of similar parental genes. The genes from sheep cannot work with genes from a kangaroo to drive development producing hybrid "sheegaroos" and "kangareeps".

Hannah - Veronica and Martin discussed other ways that we can combine and tweak genes, including transferring one or two genes from humans into another species, and a line of goats have recently been created in this way to help patients who can't produce their own anti-coagulant. There are also chimeras where stem cells from different species are mixed. For example, there's a mouse with human liver cells and we hope that we can use this mouse to help evaluate the safety of drugs as the liver plays such an important role in drug metabolism. But Martin emphasises...

Martin - There are lots of examples of that sort, but all of those mice look like mice and all of those goats look like goats, and none of them produce what you'd need for it to be a new species. That is, something which has a distinctive appearance and which can continue breeding in a way that you have created something that propagates itself. Even the natural species mixtures, such as mules, there are zebra-horse crosses, and lion-tiger crosses, but they're sterile. They do look pretty intermediate, but they don't breed. So we haven't gotten to the point of creating new species yet.