Edited by Dava Sobel.


We think the world belongs to us
but scientists have weighed life
on Earth, which turns out to be

mostly trees. Only one hundredth
of the living swim the seven seas.
One-eighth are buried: bacteria.

Underground bacteria weigh more
than a thousand times more than us.
Even worms outweigh us, three to one.

So does the lowly virus.
Humans comprise a mere hundredth of a hundredth
of the living, .01%.

Yet we have paved the earth with chicken bones.
Weep into your soup: under a third of birds
fly free—the rest, poultry.

Garden turned feedlot
and slaughterhouse—we, Homo sapiens,
one-third of all mammals, keep

almost two-thirds to eat, mostly cow
and pig. Only four percent left
for all wild animals, elephant to shrew.

Half of Earth's creatures
have vanished in the last half-century
while we've redoubled.

Even half-gone, plants outweigh us seventy-five hundred to one.


I let the cat out—
I felt the cat
hunkered in her fur

eyes bright in the dark
amidst all the wild things
crouched in their night

tygers to mice
the tiny remnant left
each one fighting for its life.

Author's Note: Proportions are based on percentages of biomass, not numbers of creatures. Source: “The Biomass Distribution on Earth,” by Yinon M. Bar-On, Rob Phillips and Ron Milo, in PNAS; June 19, 2018.