While baby mammoth Lyuba was being unwrapped at the Natural History Museum by my boss Adrian Lister, I was at Broadcasting House for Start the Week, to discuss the thorny subject of Alien Invaders. Not the out of space kind but the movement of animals across the globe, and the emotional subject of the value of native vs non-native species.

You can listen to the programme here.

On the programme with me were: Ken Thompson, whose new book Where do Camels Belong? addresses these issues head-on; Monique Simmons from Kew, an organisation tasked with minimising the UK’s risk from invasive plant species; and John Lewis-Stempel, whose new book The Private Life of an English Field mourns the loss of traditional farming methods — and a number of well-loved, if non-native species alongside. I gave a palaeontological perspective to the discussion. Plus a preview of Mammoths: Ice Age Giants! and some bonus dwarf mammoths.

I never really felt the discussion really took off – but it was fun nonetheless. In particular I felt that Ken (on the program and in his book) was a little bit naughty in shifting effortlessly between the idea of ‘non-native’ species and ‘invasive’ species. I agree that the idea of a ‘native’ British fauna is highly problematic, but it isn’t really fair to paint conservationists as idealogical zealots here: the species they most worry about are the invasive ones. The ones that swamp out all others, reducing local biodiversity and often causing other species to go extinct.

And yes, while species distributions change through time making the idea of a natural baseline highly era-specific, once you accept that maybe ‘natural’ isn’t the be-all and end all it is time for a more challenging discussion: what is it that we value about our environment and the species around us? What kind of world do we want to leave behind?

There aren’t any easy answers to that, but I suspect the answer isn’t throwing up our hands and doing nothing at all.

Ken’s book is really a long-form version of this paper by Mark Davis et al [££] from 2011, which he was a co-author on. It generated quite a number of responses from ecologists at the time: see this letter by Dan Simberloff [co-signed by 141 other scientists; ££]. If you have access to Nature, they are both well worth a read, as are the references they cite!