E.O. Wilson is championing a goal of “Half Earth” for maintaining biodiversity, meaning we would set aside fifty percent of the planet’s land for preserves and parks where non-human species could thrive. Wonderful idea though it is, that will be a steep climb. Audacity is necessary, however. At the Biodiversity Foundation website, Wilson has republished a Mosaic piece in which he and molecular biologist Sean B. Carroll engage in a wide-ranging conversation about conservation, among other scientific matters. An excerpt:

E.O. Wilson: 

You probably haven’t heard of it, but I’ve been in from the beginning of the campaign in Alabama to create a national park of hundreds of thousands of acres. [The Mobile-Tensaw Delta] would be the most biodiverse park in America, with a tremendous variety of organisms: 350 species of fish and then, to the north, the Red Hills and the Appalachians – deeply divided terrain with relic plants and animals that were left behind during the retreat of the glacier 10,000 years ago. The people down there have just woken up to what we have.

Sean B. Carroll:

I was in Yellowstone National Park in August with Liz Hadly from Stanford University, and it still possesses all the mammal species that were there 3,000 years ago. We know this from what the pack rats put into the caves in Yellowstone – and if all the mammals are there, you can feel pretty comfortable that lots of the other things are there too.

So there’s a very old park, a very large piece of ecosystem set aside, it’s enjoyed by four million people a year, but it’s a success story. It says that the first thing you do is preserve a big ecosystem and then manage it. It can be done, and it can be managed scientifically.

It doesn’t mean everything that was ever done in Yellowstone was correct, but I was impressed when Liz explained that she knows that all the mammals that were here before European settlement are still here because she’s done the cave work to look at the microfossils. We should feel good about that: grizzly bears, bisons and wolves are in Yellowstone, and they’ve been removed from almost the rest of their entire range.

E.O. Wilson:

And if you go from the USA – which, relative to the rest of the world, is in pretty good shape in terms of biodiversity and sustainability – to the tropics, everything gets worse.•