Recent studies clarify where the most vulnerable species live, where and how humanity
changes the planet, and how this drives extinctions. We assess key statistics about
species, their distribution, and their status. Most are undescribed. Those we know best
have large geographical ranges and are often common within them. Most known species
have small ranges. The numbers of small-ranged species are increasing quickly, even in
well-known taxa. They are geographically concentrated and are disproportionately likely
to be threatened or already extinct. Current rates of extinction are about 1000 times
the likely background rate of extinction. Future rates depend on many factors and are
poised to increase. Although there has been rapid progress in developing protected
areas, such efforts are not ecologically representative, nor do they optimally protect
biodiversity.