A familiar number was much bandied about during the otherwise wonderful celebration that has been the just-ended Settimana della Biodiversitá here in Rome. We have lost 75% of the diversity of crops during the past century, we were repeatedly told. So I will take this opportunity to repeat from my part that while for all I know this number may indeed be accurate, we have no evidence to that effect. Nobody has counted up all the tomato heirlooms lost in Italy, all the bean landraces lost in Mexico, all the mango varieties lost in India, all the taro clones lost in Papua New Guinea, divided by the number of those things that there used to be, repeated the feat for all other countries in which these crops are grown,1 done the whole thing again for all other crops, taken an overall average and come out with 75%. In fact, as we have said here before, that 75% number is probably an extrapolation from one, probably hardly representative, data point. We should recognize this fact, admit that we don’t know how much crop diversity has been lost overall, quote what numbers there are for genetic erosion with circumspection, and go out and get better numbers.
- Taking care to account for synonyms etc. [↩]