In the wild, where individuals of a species are dotted around and have to be sought out by their predators, having a few leaves nibbled away is a minor nuisance compared with having your root system strangled and poisoned by your neighbours.
The search is difficult because doctors, scientists and patients aren't used to thinking of rheumatoid arthritis, asthma and Alzheimer's disease as having the same root cause.
Having dedicated his career to discovering the root causes of illness, to hear him talk and to see his slides was enough to make even the most ardent junk-food aficionado rethink his or her eating habits.
But having failed to get anywhere with its proposal for voting weights based on the square root of a country's population, Poland is now talking about ways of making it more difficult for large countries to block a qualified majority vote.
He is not a natural ally of Mr Mbeki, having been ousted from his job as premier of the Free State last year: he had been trying to root out corruption.