So, in the clamour to conserve a host of iconic species, is there a case for us to be more realistic about our ability to intervene? Might the awkward fact be that we can't save everything?
It is certainly the case that the creatures with the best chance are those whose looks or adorability or loveable eyes have attracted the strongest support. No-one is fighting to save the tubeworm.
But should the emphasis change if extinctions are our fault? Or, worse than that, if the losses are accelerating because of us - by tearing up habitats or causing pollution or simply slaughtering every member of a species?
There is a long list of animals whose disappearance can be blamed squarely on human actions.
I met one of them on the Galapagos Islands a few years ago - Lonesome George, external, the last giant tortoise of his species, a lumbering, sad-eyed, endearing creature.
On his home island, the plants that he and his kind depended on had been nibbled away by goats brought by sailors, while their eggs were eaten by rats that jumped from the ships. The tortoises themselves used to be carried on board to serve as living larders.
Clearly attitudes to the natural world change over time - and vary between regions.
For a poor villager in Africa, poaching an elephant for its tusks is easy money. For people in China, ivory and rhino horn are important culturally and - wrongly - medicinally.
Conservation is a fairly new idea - ivory used to be a major staple of British Empire trading.
By contrast, I found the sight of a haul of smuggled tusks in Bangkok Airport profoundly depressing. The stench was intense and a customs officer said the ivory "smelled like death".
So what are the arguments for resisting extinction? One is purely selfish - economics.
For example, if we fish every last tuna, thousands of people in the fishing industry will lose their jobs. Likewise, if every lion or elephant is shot, the tourist trade will suffer. Extinction can cost in hard cash.
Furthermore, there may be unintended effects from eliminating "keystone" species - the loss of one plant or creature in a food chain may affect a whole web that we depend on in some way that we have not yet understood.
In Thailand, I heard that too few tigers could mean too many deer. In turn, that would mean more destruction of vegetation with a knock-on impact on the birds and monkeys that live in the trees.
Another argument is moral - that as the most powerful species on the planet, we have an obligation not to obliterate others, especially if it is through wanton carelessness.
In other words, a mark of civilisation would be to feel responsibility for the survival of weaker species.
A final point that I find compelling is that we are the first species to have gained the remarkable knowledge that every living thing has its DNA at its heart. We all share that.
We may not like everything - ants, spiders, slugs and snakes - but we are related to them. In an extremely loose sense, they are family. And that casts the threat of extinction - and our role in it - in a very different light.
David Shukman's report What's wrong with extinction? will be broadcast in a new programme, BBC News: The Editors, starting on BBC1 on 25 March at 23:15 GMT.